Mechanical behaviour and energy absorption of closed-cell aluminium foam
Quasi-static axial compression of thin-walled circular aluminium tubes
International Journal of Mechanical Sciences 43(2001)2103–2123Quasi-static axial compression of thin-walled circular aluminium tubesS.R.Guillow a ,G.Lu a ;∗,R.H.Grzebieta ba School of Engineering and Science,Swinburne University of Technology,PO Box 218,Hawthorn,Victoria 3122,Australiab Department of Civil Engineering,Monash University,Clayton,Victoria 3168,AustraliaReceived5October 2000;receivedin revisedform 26March 2001AbstractThis paper presents further experimental investigations into axial compression of thin-walledcircular tubes,a classical problem studied for several decades.A total of 70quasi-static tests were conducted on circular 6060aluminium tubes in the T5,as-receivedcond ition.The range of D=t considered was expanded over previous studies to D=t =10–450.Collapse modes were observed for L=D 610anda mod e classiÿcation chart developed.The average crush force,F AV ,was non-d imensionalisedandan empirical formula establishedas F AV =M P =72:3(D=t )0:32.It was foundthat test results for both axi-symmetric and non-symmetric modes lie on a single prehensive comparisons have been made between existing theories andour test results for F AV .This has revealedsome shortcomings,suggesting that further theoretical work may be required.It was found that the ratio of F MAX =F AV increasedsubstantially with an increase in the D=t ratio.The e ect of ÿlling aluminium tubes with di erent density polyurethane foam was also brie y examined.?2001Elsevier Science Ltd.All rights reserved.Keywords:Axial compression;Circular tube;Foam;Plastic collapse;Thin-walledtubes0.IntroductionThe behaviour of thin-walledmetal tubes subjectedto axial compression has been stud iedfor many years.Such tubes are frequently usedas impact energy absorbers andReid[1]has pre-sented a general review of deformation mechanisms.Fig.1shows a typical force–displacement curve for quasi-static loading.Generally speaking,the axial load rises until a ÿrst buckle is formedat a characteristic maximum force value,F MAX .This initial buckling behaviour is well ∗Corresponding author.Fax:+61-3-9214-8264.E-mail address:glu@.au (G.Lu).0020-7403/01/$-see front matter ?2001Elsevier Science Ltd.All rights reserved.PII:S 0020-7403(01)00031-52104S.R.Guillow et al./International Journal of Mechanical Sciences43(2001)2103–2123NomenclatureD average diameterF AV average axial forceF MAX maximum axial force forÿrst peakg acceleration due to gravityH half-wavelength of foldL lengthM P full plastic bending moment of tube wall per unit lengthm geometric eccentricity factor—i.e.ratio of outward s foldlength to total foldlength N number of circumferential lobes(or corners)in non-symmetrical bucklingR average radiust wall thickness of tubeV Vickers hardness number(kg=mm2)e e ective crushing distancef density of foam0 ow stress0:20.2%proof stressult ultimate tensile stressFig.1.Typical load–de ection curve for an axially loaded thin-walled metal tube which collapsed by progressive folding.S.R.Guillow et al./International Journal of Mechanical Sciences43(2001)2103–21232105Fig.2.Examples of various collapse modes for thin-walled circular6060-T5aluminium tubes under axial load-ing(more examples shown in Fig.11):(a)axi-symmetric mode(D=97:9mm;t=1:9mm;L=196mm);(b)non-symmetric mode(D=96:5mm;t=0:54mm;L=386mm);(c)mixedmod e(D=97:5mm; t=1:5mm;L=350mm).known and will not be studied in depth here.Thereafter,depending on geometrical parameters such as the ratios of D=t(diameter=thickness)and L=D(length=diameter)and also on material properties,there are a variety of possible modes of collapse.Generally,collapse involves plastic2106S.R.Guillow et al./International Journal of Mechanical Sciences43(2001)2103–2123Fig.3.Schematic axial view of non-symmetric or diamond collapse mode.Two cases are shown,N=3and4 circumferential lobes.buckling andthe formation of progressive fold s(whether axi-symmetric or non-symmetric).The formation of these folds causes the characteristic uctuation in the axial force shown in Fig.1. This plastic collapse behaviour is of primary interest in this paper.Experimentally the following modes of collapse have been observed and Fig.2shows some typical examples:(i)axi-symmetric concertina bellowing,(ii)non-symmetric buckling(also known as diamond or Yoshimura mode),with a variable number of circumferential lobes or corners(refer to Fig.3),(iii)mixed mode(combination of the two previous modes),(iv)Euler or global buckling;and(v)other(simple compression,single fold s,etc.).Research on circular tubes in the past has generally concentratedon annealedaluminium or steel tubes with D=t ratios between10and150.It is common ind ustrial practice to use aluminium alloys in the heat treatedas-receivedcond ition,but little research appears to have addressed this particular case.Moreover,Gupta and Gupta[2]have identiÿed metal temper as one of the signiÿcant factors in determining behaviour.Hence,it was decided to undertake an experimental program to extendthe range of research up to approximately D=t=450andto test aluminium alloy tubes which were in the heat treatedas-receivedcond ition.This work is of potential application in civil,mechanical,marine andaeronautical engineeringÿeld s.1.Review of previous studiesThe following section summarises the available literature on the plastic collapse behaviour of thin-walledcircular metal tubes subject to quasi-static axial load ing.It is arrangedbroad ly in a chronological order.Theÿrst signiÿcant work to address the mechanics underlying the observed behaviour of axially load edthin-walledtubes was by Alexand er[3].He proposeda simple mod el for the axi-symmetric foldpattern(refer to Fig.4)basedon experiments with metal tubes of D=t= 29–89.At a global level,external work done was equated with internal work from bending at three stationary plastic hinges andcircumferential stretching of the metal between the hinges.S.R.Guillow et al./International Journal of Mechanical Sciences 43(2001)2103–21232107Fig.4.Axi-symmetric collapse mechanism assumedby Alexand er [3].Thus the following theoretical equation was obtainedfor average crush force (axi-symmetric folds):F AV =K o t1:5√D;(1)where K is a constant and o is the ow stress.Also,plastic half-wavelength,H (refer to Fig.4)was determined as follows:H =C √Dt;(2)where C is a constant.The experimental results observedby Alexand er were generally in agreement with the above two equations.Although simple,this model seems to re ect the und erlying physical processes involvedandmany subsequent researchers have usedit as a starting point.Pugsley andMacaulay [4]were among the ÿrst researchers to consid er the non-symmetric folding mode,their study being largely empirical.Johnson et al.[5]attempted to develop a theory for the non-symmetric mode based on the actual geometry of folding,with the tube material at the mid-surface being considered inextensional.Hence they were able to develop equations to predict average axial crush force,F AV .However,agreement between their model andtest results for P.V.C.tubes was not particularly good .In 1978Magee andThornton [6]cond ucteda review of previous work by researchers who hadcond uctedaxial crushing tests on circular metal tubes.By consid ering these collectedd ata they d evelopeda number of empirical equations which involvedthe speciÿc ultimate tensile strength of the metal.Andrews et al.[7]conducted a comprehensive series of tests on annealed aluminium alloy tubes covering a wide range of D=t (4–60)and L=D (0:2–8:8).Consequently,they developed a collapse mode classiÿcation chart which predicted the mode of collapse for any given D=t and L=D combination.2108S.R.Guillow et al./International Journal of Mechanical Sciences43(2001)2103–2123Fig.5.Axi-symmetric mod el usedby Abramowicz andJones[8,9].H is the half-wavelength of the fold. Abramowicz andJones[8,9]cond uctedaxial compression tests on a range of thin-walledcir-cular andsquare steel tubes.They analytically consid eredboth axi-symmetric andnon-symmetric modes.Abramowicz introduced the important concept of e ective crushing distance, e(refer to Fig.5),where a foldconsistedof two equal rad ii segments of length H,curvedin opposite d irections andthe material hadÿnite thickness.For axi-symmetric folds,Abramowicz and Jones[9]developed the following equation in1986 (anda similar one in1984[8]):F AV M P =[25:23D=t+15:09][0:86−0:568t=D];(3)where M P= o(t2=4):For non-symmetric fold s,in1984[8]and1986[9]Abramowicz andJones commencedwith two di erent starting relationships.Taking into account e ective crushing distance,material strain rate,etc.,resultedin two d i erent equations for average crush force.The simple relation-ship d evelopedin1984[8]appliedregard less of the number of lobes:F AV M P =86:14Dt0:33:(4)However,thisÿnding appears to have developed from work carried out by Wierzbicki and Abramowicz[10]on rectangular rather than circular tubes.On the other hand,the relationshipS.R.Guillow et al./International Journal of Mechanical Sciences43(2001)2103–21232109Fig.6.Collapse mechanism assumedby Grzebieta[12]for axi-symmetric mod e. Abramowicz andJones d erivedin1986[9]was of the formF AV M P =A N1Dt+A N2;(5)where A N1and A N2are constants which were a function of the number of lobes.For further details the reader is directed to this reference.In Refs.[8,9],Abramowicz andJones observedthat reasonable agreement existedbetween pred ictions of average crush load s basedon the above notedequations andtheir experimental results for steel tubes with D=t=9–65.In a subsequent work,Abramowicz andJones[11] reportedon further tests andsummarisedtheirÿnd ings for both static andd ynamic load ing cases in two failure mode maps,adding to the previous work by Andrews et al.[7].Gupta andGupta[2]performeda series of quasi-static axial compression tests on thin-walled aluminium andmildsteel circular tubes in both the annealedandas-receivedcond itions.They combinedall results andd evelopedempirical equations for the average crushing force in terms of the Vickers hardness and D=t.Grzebieta[12–14]useda strip methodto analyse both axi-symmetric andnon-symmetric folding modes.He equated external work done with internal energy from horizontal,inclined and travelling plastic hinges as well as stretching of the metal,to produce equations for determining the instantaneous forces involved.Unfortunately,these equations do not yield simple expressions for determining the average crush force.Grzebieta’s collapse mechanism model for axi-symmetric mode(refer to Fig.6)was a mod-iÿcation of Alexand er’s.A foldconsistedof three equal lengths,two of which were curves of equal rad ius andthe thirda straight line segment.For the non-symmetric mod e Grzebieta analysedthe fold s as a half-d iamondmechanism.Grzebieta carriedout static andd ynamic tests on steel tubes with D=t=30–300.2110S.R.Guillow et al./International Journal of Mechanical Sciences 43(2001)2103–2123Fig.7.Axi-symmetric mod el usedby Wierzbicki [15]andSingace et al.[16,17].Wierzbicki et al.[15]introduced a new model for the axi-symmetric collapse mechanism (shown simpliÿed in Fig.7)which allows for both inwards and outwards radial displacement.The geometry is governedby an arbitrary geometric eccentricity factor,m ,which is deÿned as the ratio of outwardfoldlength to total foldlength.By consid ering energy rate equations Wierzbicki et al.[15]were able to develop equations for not only determining average crush load but also a representative load–de ection history.The latter helped explain the experi-mental observation that sometimes there are two force peaks during the formation of a single fold.Singace et al.[16,17]extended upon the previous work by Wierzbicki et al..For the axi-symmetric mode,they considered a global energy balance leading to an implicit equation for m ,which when solvedgave a theoretical constant value of m =0:65.In their secondpa-per [17],Singace et al.reportedgoodexperimental agreement with the pred ictedvalue of 0:ter,Singace et al.[18]re-considered the eccentricity factor,m ,for the non-symmetric mode case.From the results of experiments on a small range of circular metal tubes they de-duced that the factor m was (surprisingly)approximately constant at m =0:65for this mode also.The equations developed by Singace et al.[17,18]for calculating average axial crush force are as follows.For axi-symmetric mode:F AV M P =22:27 D t+5:632:(6)For non-symmetric mode:F AV M P =− 3N +2 2N tan 2N D t :(7)One particular problem of interpretation arises with most theoretical equations developed for non-symmetric mode collapse,for example Eq.(7).They require a knowledge of the number of lobes,N ,at a given D=t ratio.We have not foundany publishedequation entirely satisfactory in determining N .S.R.Guillow et al./International Journal of Mechanical Sciences43(2001)2103–21232111Fig.8.Experimental set-up.With regardto energy absorption,it has been suggestedthatÿlling metal tubes with low-density polyurethane foam(to provide wall stability)may be preferable to increasing the wall thickness.Early investigations into the e ectiveness of this foamÿlling methodwere cond ucted by Thornton[19]and Lampinen and Jeryan[20].Reid,Reddy and Gray[21]have conducted experiments on the axial compression of thin-walledrectangular metal tubes which hadbeen ÿlledwith foam.Red d y andWall[22]subsequently testedfoamÿlledcircular aluminium alloy cans.Academic opinion appears to be divided about the relative beneÿts of foamÿlling versus increasing the wall thickness.2.Test procedure and material propertiesA series of approximately70axial compression tests were conducted under quasi-static condi-tions.Tests were carriedout on a SHIMAD ZU universal testing machine which appliedthe axial loadthrough at endplatens(refer to Fig.8).Cross-headspeedwas approximately5mm=min.A LABTECH data-logger recorded the data digitally for later analysis.The tubes tested were made from commercial quality extruded6060aluminium alloy in the as-received,heat treated T5condition.Mechanical properties were determined from tensile testing of coupons cut from several tubes.Fig.9shows a stress–strain curve for a typical tensile test specimen which hada0.2%proof stress, 0:2,of180MPa,an ultimate stress, ult, of212MPa anda Vickers hard ness,V,of73kg=mm2.By averaging results from several tensile tests we were able to determine an empirical relation between the0.2%proof stress and Vickers hardness for this particular type of alloy as follows:Vg= 0:2=3:92,where g=9:81m=s2is the gravitational acceleration.2112S.R.Guillow et al./International Journal of Mechanical Sciences43(2001)2103–2123Fig.9.Typical tensile stress–strain curve for6060-T5aluminium.Fig.10.Stress–strain curves for polyurethane foams of three di erent densities.The variety of commercial tubes available was insu cient to achieve the full range of D=t values we required.To produce tubes with very large D=t ratios,the outside surface of stock tubes was machined to produce the wall thickness desired.Theÿnal thickness,mean diameter and Vickers hardness were measured for each compression testpiece.Vickers hardness read-ings were usedto quantify the mechanical properties of each tube testpiece through the above equation.A representative sample of these tube properties andthe results of our testing may be foundin the append ix.Most tests involvedempty aluminium alloy tubes.However,some tests were carriedout on aluminium alloy tubes which hadbeenÿlledwith polyurethane foam.This polyurethane foam usually comes as a two part mix(base andaccelerator)andwe usedthree d i erent d ensities (35,60and140kg=m3)during testing.Fig.10shows typical compressive stress–strain curvesfor the three di erent density foams,which were obtained from axial compression tests on 96mm diameter cylindrical foam blanks unrestrained laterally.3.Experimental results and discussionOur experimental results are summarisedon the following pages in terms of the collapse mode,average force F AV,force ratio F MAX=F AV,eccentricity factor m andthe e ect of foam ÿlling.3.1.Collapse modeFurther examples of collapse modes are shown in Fig.11,in addition to those shown in Fig.2.Of particular interest was the non-symmetric mode(refer to Fig.2b)which has multiple corners(or lobes).We observedthat for tubes with an increasing D=t ratio,the number ofFig.11.Further examples of collapse modes for axially loaded thin-walled6060-T5aluminium tubes: (a)mixedmod e(D=57:1mm;t=1:15mm;L=628mm);(b)three sided non-symmetric folding (D=57:1mm;t=1:15mm;L=628mm);(c)Euler buckling(D=58mm;t=2:0mm;L=566mm).Fig.12.Schematic axial view of spiralling non-symmetric folding with N=312lobes,from Grzebieta[13].Fig.13.Mode classiÿcation chart for circular6060-T5aluminium tubes. circumferential lobes also increasedfrom2up to5or6.At high values of D=t(¿200),the number of lobes often variedd uring testing(in one case erratically between3,4and5lobes). The number of lobes,N,was not always an integer—for example,in some cases we observed a relatively stable pattern with312lobes in a spiralling arrangement(refer to Fig.12).In other cases the lobes were simply incompletely formed.From our test results for as-received6060-T5aluminium tubes a mod e classiÿcation chart was produced,see Fig.13.This chart is divided up into areas which correspond,approximately, to the di erent modes of collapse.The general shape of our chart is similar to that produced by And rews et al.[7],who testedannealedaluminium tubes.However,there are noticeable di erences in the location of the lines delineating the various areas.For example,consider analuminium tube with D=t=50and L=D=10.From our chart we wouldexpect a mixedmod eFig.14.Plot of non-dimensional experimental average force F AV=M P versus D=t.collapse but from Andrews et al.chart an Euler collapse is indicated.Note that a logarithmic scale is usedfor D=t on our chart in order to cover the wider range of D=t values considered.It may be observed broadly from our chart that non-symmetric mode is present when D=t¿100, while axi-symmetric mode occurs when D=t¡50and L=D¡2.3.2.Average crush forceOne of the most signiÿcant parameters for quantifying the behaviour of axially compressed tubes is the average crush force F AV.This is usually expressednon-d imensionally as a ratio F AV=M P.When calculating the plastic moment,M P,di erent researchers have used various di erent measures for the ow stress, 0.Since our tests involvedonly aluminium we chose to take the value of0.2%proof stress, 0:2,as the ow stress.Thus e ectively:M P= 0:2(t2=4):Fig.14shows our test results for non-dimensionalised average axial force,F AV=M P,plotted logarithmically versus D=t.There is only a relatively small amount of experimental scatter(some points shown represent more than one test result).Note that when calculating the average axial force,F AV,results for the initial peak have been ignored.From Fig.14it can be seen that when plottedlogarithmically,all the results(whether axi-symmetric,non-symmetric or mixed modes)approximately form a straight line.Hence,we obtained the following empirical relation for6060-T5aluminium alloy tubes:F AV M P =72:3Dt0:32:(8)This equation is of similar form to Eq.(4)proposedby Abramowicz andJones in1984[8] for non-symmetric mode but quite di erent from the corresponding equation proposed by Gupta andGupta[2].parison of present experimental results for average crush force with empirical equations of Gupta and Gupta[2].parison of experiment and theory for average forceThe following paragraphs are a subjective comparison between our experimental results for average crush force,F AV,andvarious theories andempirical relationships.Fig.15shows our test results for F AV comparedwith empirical equations by Gupta andGupta [2].They usedVickers hard ness,V,to characterise material properties.These equations were determined from tests on metal tubes with a relatively small range of dimensions(D=t=10–33, L=D=2–3).In view of this,agreement for both axi-symmetric andnon-symmetric mod es is quite goodin the range D=t=10–100.For D=t¿100,their curve for axi-symmetric mode is closer to our experimental test points than their non-symmetric one,even though the actual collapse mode exhibited was non-symmetric.Fig.16shows our test results for average force,comparedwith equations d evelopedby Abramowicz andJones[8].From thisÿgure it may be seen that agreement for both axi-symmetric and non-symmetric modes is fair.Their axi-symmetric equation predicts average forces which are rather low comparedwith our test points.On the other hand,their equation for non-symmetric mode,Eq.(4),predicts average forces which are rather high compared with our test points. Nevertheless,it may be notedfrom Fig.16that the slope of the line representing Eq.(4) (non-symmetric mode)is almost the same as our test points.This is also evident from a comparison of Eqs.(4)and(8).Fig.17shows our test results for average force,F AV,comparedwith the theoretical equations d evelopedby Abramowicz andJones[9].Their axi-symmetric Eq.(3)estimates an average force which is still low comparedwith our test results,but closer to our test points than their 1984prediction.In the case of non-symmetric collapse,Abramowicz and Jones[9]developed Eq.(5),which produces a family of lines,one for each value of N.Thus,we needto know the number of lobes,N,in order to interpret Fig.17.From the appendix it will be noted that formost of the tubes we tested,N falls in the range N=3–4.Agreement between their theory andparison of present experimental results for average force with theory by Abramowicz andJones[8].parison of present experimental results for average force with theory by Abramowicz andJones[9]. our test points is goodin this range.For cases with low D=t values(¡50),where N¡3,their prediction for F AV is rather low.For high values of D=t(¿300),where N¿4,their predicted value for F AV is rather high.Nevertheless,overall it appears that this methodof pred icting F AV is satisfactory.Fig.18shows our test results for average force comparedwith the equations d evelopedby Singace et al.[17,18].Their equation for axi-symmetric mode,Eq.(6),gives values for F AV which are much too low comparedwith our test points.In the case of non-symmetric mod e, their Eq.(7),when plottedon logarithmic axes prod uces a series of very steep lines,one for each number of lobes,N.This makes the process of interpretation even more di cult. Determining the precise number of corners or lobes for each test specimen presents somepractical di culties.As has previously been noted,if D=t¿200we sometimes observedthatparison of present experimental results for average force with theory by Singace et al.papers [16–18].the number of lobes variedd uring the one test.Nevertheless,on Fig.18test points are shown for which we felt conÿdent of the lobe number.It will be noted that the lines representing the Singace et al.Eq.(7)are not inconsistent with our test points although agreement is not close.However,we observedthat when the number of lobes variedd uring testing there was not a corresponding variation in the instantaneous crush force.This observation casts doubt on the validity of Eq.(7),as the large gaps between the lines in Fig.18suggest there should be a large variation in crush force with a change in the number of lobes,N .3.4.Discussion of average forceAt this stage the following observations may be made.In general,the existing theories produce numerical predictions for average force which are reasonable only for a limited range of D=t .Comparison of our test results with these theories has revealedtwo fund amental features which remain inexplicable at present.The ÿrst feature is that all our test points,regardless of mode of collapse (axi-symmetric or non-symmetric),lie on one curve whereas the theories treat these modes quite separately.Further,most theories for non-symmetric mode predict average forces which are a function of the number of lobes but experimentally this does not appear to be the case.The second,more important,feature relates to the functional dependence of average force on D=t .Our experiments clearly show that F AV =M P is empirically dependent on (D=t )0:32.Existing theories for axi-symmetric mode,however,suggest that F AV =M P should be dependent on D=t .In the case of non-symmetric mode,a wide variety of theories have been suggested;typically F AV =M P is seen as being a linear function of D=t as for the Singace et al.Eq.(7).An exception to this is Eq.(4)d evelopedby Abramowicz andJones [9],where F AV =M P was proportional to (D=t )0:33.However,as previously noted,this equation appears to have developed from work by Wierzbicki andAbramowicz [10]on rectangular rather than circular tubes.Thus it seemsFig.19.F MAX=F AV force ratio versus D=t.that for circular tubes a rigorous theoretical explanation of the D=t exponent of13is still to be developed.3.5.Force ratio F MAX=F AVIn a previous paper,Guillow andLu[23]id entiÿedthe force ratio F MAX=F AV as being of some interest.In that paper it was notedthat F MAX=F AV variedas a function of D=t ratio(this has also been notedby other researchers).The variation in force ratio highlights the fact that the mechanics of formation of the initial and subsequent folds is substantially di erent.Fig.19 shows the results of our more recent tests at larger values of D=t.The F MAX=F AV ratio appears to be monotonically increasing up to D=t=450.Variability in the F MAX=F AV ratio increased markedly for D=t¿100.This scatter couldbe d ue to signiÿcant variation in the initial buckling force,F MAX,at large values of D=t.Incidently,the common wisdom attributes the scatter of initial buckling force to imperfection sensitivity of thin-walled shells.However,Calladine[24]has recently provided an alternative explanation basedon post-buckling consid erations.3.6.Eccentricity factor mWhen folds occur during progressive buckling,they form partly on the outside and partly on the inside of the original tube proÿle.As previously noted,Singace et al.[16–18]have investigatedthis phenomenon by consid ering the eccentricity factor,m,(refer to Fig.7for its deÿnition).We were surprised at their claim that the factor m was approximately constant at 0.65.Therefore,we decided to examine our test pieces to see if the Singace et al.ÿndings also applied to6060-T5aluminium alloy tubes.Our test results for axi-symmetric mode folding are shown in Fig.20.They appear to conÿrm that a constant value of approximately0.65alsoapplies in this case.(It is not clear why the m value shouldbe so d i erent at D=t=20.)Fig.20.Eccentricity,m,as a function of D=t,for axi-symmetric mode.Fig.21.E ect of varying density of foamÿlling in6060-T5aluminium tubes.All tubes of length196mm,average diameter97mm and thickness1:0mm.Refer to Fig.10for stress–strain curves of polyurethane foam.3.7.E ect of foamÿllingMost of our tests involvedempty aluminium alloy tubes.However,a few tests were carried out on aluminium alloy tubes which hadbeenÿlledwith polyurethane foam.Fig.21shows some of our test results for foam-ÿlledaluminium tubes andTable1presents the d ata for aver-age axial crush force.Stress–strain curves for foam only were presentedearlier in Fig.10.All of the aluminium alloy tubes usedin this stage of testing were id entical(D=97mm;t=1:0mm and L=196mm).Test results for an identical empty aluminium tube are shown in Fig.1. We expectedto observe an increase in the average crushing force,F AV,for aluminium alloy tubes which hadbeenÿlledwith foam,as comparedwith id entical empty aluminium tubes.In fact,there is a complex interaction between the metal tubes andthe foamÿlling.The foamprovides support for the thin walls of the aluminium tubes leading to an increase in the overall。
玻璃纤维铝合金层板(FMLs)的疲劳损伤特性及S-N曲线
玻璃纤维铝合金层板(FMLs)的疲劳损伤特性及S-N曲线马玉娥;王博;熊晓枫【摘要】根据国内外标准和参考文献,针对玻璃纤维增强铝合金层板(FMLs)的特点设计出FMLs疲劳试验件,进行了不同载荷下的R=0.1等幅拉-拉疲劳试验.疲劳试验过程中FMLs最先在表面铝层内出现裂纹,随后表面铝层可见多条裂纹.随着循环载荷数的增加,裂纹不断扩展,并在界面出现分层现象,然后分层损伤快速扩展直至完全断裂破坏.测得了FMLs的疲劳裂纹起裂寿命和裂纹扩展寿命,给出了其疲劳寿命的规律性.得到了FMLs和同样厚度碳纤维复合材料CCF300的S-N曲线,并进行了对比.FMLs的疲劳寿命随载荷变化平缓,近似成对数趋势;在载荷大于400 MPa时FMLs的疲劳寿命与CCF300碳纤维复合材料层板相当;当疲劳载荷最大值低于300 MPa,FMLs的疲劳寿命比CCF300复材板要低.为飞机结构设计师们提供了材料基础性能和信息.【期刊名称】《西北工业大学学报》【年(卷),期】2016(034)002【总页数】5页(P222-226)【关键词】玻璃纤维增强铝合金层板;疲劳裂纹起裂寿命;裂纹扩展寿命;分层扩展;S-N曲线【作者】马玉娥;王博;熊晓枫【作者单位】西北工业大学航空学院118号,陕西西安 710072;西北工业大学航空学院118号,陕西西安 710072;中航工业成都飞机设计研究所,四川成都 610041【正文语种】中文【中图分类】V215.5材料的疲劳性能是飞机结构设计选材考察的重点之一。
为克服传统铝合金结构疲劳性能相对较差的问题，同时充分利用复合材料对疲劳载荷不敏感的特性，国外研究者提出了金属和复合材料的混杂材料。
根据金属和复合材料的不同，研制出不同的纤维增强合金层合板类型，如第一代的Arall(aluminum with aramid fibers)是由铝合金层和芳纶纤维交替组成，CARALL(aluminum with carbon fibres)由铝合金和碳纤维组成，GLARE(aluminum with glass fibers)是由铝合金和玻璃纤维组成，还有最近发展由钛合金和碳纤维组成的TiGr(titanium with carbon fibers)和由镁合金和玻璃纤维组成的MgFML(magnesium with glass fibers)。
克洛布尔阿尔法 YV 93-1202 前级滑动剂用于气氧传输设备、管道和装置说明书
Product informationKlüberalfa YV 93-1202,Prod. 013006,enEdition 23.12.2019 [replaces edition 31.10.2019]Benefits for your application–High operational safety for installations and components carrying gaseous oxygen –due to high oxygen pressure resistance (see product data)–due to good compatibility with most materials used in this branch of industry –due to a wide service temperature range–Also suitable for installations and components carrying liquid oxygen –Each product batch is checked for its reactivity to oxygenDescriptionKlüberalfa YV 93-1202 is a white sliding agent with a good wetting capacity on the basis of perfluorinated polyether oils and solid lubricants.Klüberalfa YV 93-1202 provides an exceptionally high stability to oxygen surges and very good resistance to various chemicals.To ensure continuous adherence to this high quality standard,Klüberalfa YV 93-1202 is manufactured in small series subject to strict hygiene requirements and each batch is inspected based on M 034-1 list of nonmetallic materials (213-075).Klüberalfa YV 93-1202 is registered according to NSF H1,complies with FDA 21 CFR § 178.3570 and can be used in the food-processing industry.ApplicationKlüberalfa YV 93-1202 is used as a sliding agent for thelubrication of valves, fittings and installations carrying gaseous and/or liquid oxygen, in individual cases subject to gas pressures considerably above 300 bar, or in chemicalinstallations and equipment requiring high resistance to various gases.(Conclusion by analogy based on chemical composition. We recommend users conduct their own component tests using the complete component under conditions similar to series application).The product's high pressure-absorption capacity and consistent friction values over a wide temperature range ensure constant actuation forces. Test results show the product's usability for an O2 content > 21 % by vol. under operating conditions specified in the product data section of this product information leaflet.Possible applications are:–Oxygen valves–Peripheral aggregates of chemical installatons–Hose couplings, e.g. oxygen pipe connections, sliding and plain bearings, bolts, slideways, etc.–Steel and heavy industry–Assembly aid for most rubber-elastic materials and plastics –For industrial handling, maintenance and care of oxygen components Behaviour towards metal, elastomers and plasticsKlüberalfa YV 93-1202 is normally neutral towards metallic materials, plastics and elastomers within the envisagedtemperature range. Nevertheless, we recommend checking the compatibility of the sliding agent with materials prior to the introduction of this product.Application notesAll surfaces to be wetted must be thoroughly cleaned prior to product application. The friction and lubrication points of these surfaces/components must be clean and bright (i.e. free from oil, grease, dirt particles or perspiration, etc.). For optimum lubrication results, we recommend cleaning the friction points with clean white spirit and then Klüberalfa XZ 3-1, ensuring residue-free surfaces when dried. Application to equipment,valves and fittings carrying oxygen must also be "oxygen clean"to attain a "ready for oxygen service" condition.For use at low temperatures, e.g. where components are in direct contact with liquid oxygen, experimental testing and approval by the component manufacturer is required since the design and power ratings, for example in actuator gears, may play a decisive role in this context.For optimised service life, please contact our service engineers.* Notes on the lower service temperature limit (see product data): The service temperature is defined on the basis of physical and mechanical-dynamic product characteristics. At very low temperature and pressure, however, where oxygen remains fluid, the product retains its stability in liquid oxygen tests. If the product is intended to be used below the lowerKlüberalfa YV 93-1202Premium sliding agent for valves, fittings and installations carrying oxygen under very high partial pressureKlüberalfa YV 93-1202,Prod. 013006,enEdition 23.12.2019 [replaces edition 31.10.2019]service temperature limit, it has to be checked if reliableoperation of the component is ensured under these conditions.In cases of doubt, application-specific tests would have to be performed.** Notes on the upper service temperature limit (see product data): The service temperature is defined on the basis of physical and mechanical-dynamic product characteristics.When working in an atmosphere with added oxygen and/or under high oxygen partial pressure, the upper service temperature limit may be reduced due to a reaction with oxygen. To assess whether use in a particular application is safe, please refer to the product data section in this product information. In cases of doubt, application-specific tests would have to be performed.Safety advice:The resistance to oxygen was determined with the unused,contamination-free product. If the product is decomposed during use due to physical (temperature, electric discharge,pressure surges) or chemical influence or contaminated by foreign substances (e.g. easily oxidisable organic or inorganic materials, particularly iron metals, magnesium, aluminium,titanium or their alloys, e.g. rubbed-off particles, contamination from the environment), decomposition products or foreign substances can be generated which clearly reduce oxygen resistance. Furthermore, operating conditions have a major impact on the lubricant's behaviour in the application.Therefore, it can be necessary or prescribed to conduct own safety-relevant examinations on the equipment or lubricated component.Material safety data sheetsMaterial safety data sheets can be requested via our website . You may also obtain them through your contact person at Klüber Lubrication.Product information。
汽车轻量化技术的研究与进展
汽车轻量化技术的研究与进展作者：范子杰， 桂良进， 苏瑞意， FAN Zijie， GUI Liangjin， SU Ruiyi作者单位：清华大学汽车安全与节能国家重点实验室,北京100084,中国刊名：汽车安全与节能学报英文刊名：JOURNAL OF AUTOMOTIVE SAFETY AND ENGERGY年，卷(期)：2014,5(1) Government Printing Office Partnership for a New Generation of Vehicles (PNGV):assessment of programgoals,activities,and priorities 19962.American Iron and Steel Institute UltraLight steel auto body final report 20143.American Iron and Steel Institute ULSAB-AVC overview report 20024.EAA (European Aluminium Association),Aluminium in Cars 20085.杨阳;周谊;桂良进双扭杆双横臂悬架有限元建模与分析 2006(11)6.桂良进;范子杰;陈宗渝“长安之星”微型客车白车身刚度研究 2004(09)7.周长路;范子杰;陈宗渝微型客车白车身模态分析 2004(01)8.郝春鹏;范子杰;桂良进微型客车车身结构正面碰撞特性的数值模拟 2004(05)9.Gobbi M;Haque I;Papalambros P P Y A critical review of optimization methods for road vehicles design 200610.郝琪;张继伟车门结构优化设计的灵敏度分析研究 2010(05)11.桂良进;范子杰;周长路某型载重车车架结构轻量化设计研究 2003(04)12.苏瑞意;桂良进;王旭燃料电池城市客车结构有限元分析与轻量化设计 2008(12)13.刘江;桂良进;王青春全承载式大客车车身结构多目标优化 2008(02)14.丁炜琦;苏瑞意;桂良进基于应力优化的大客车结构多目标优化 2010(04)15.Botkin M E Structural Optimization of Automotive Body Components Based on Parametric Solid Modeling 2002(02)16.Shin J K;Lee K H;Song S I Automotive door design with the ULSAB concept using structural optimization 2002(04)17.XIANG Yujiang;WANG Qian;FAN Zijie Optimal crashworthiness design of a spot-welded thin-walled hat section 2006(10)18.Su Ruiyi;Gui Liangjin;Fan Zijie Multi-objective optimization for bus body with strength and rollover safety constraints based on surrogate models 2011(03)19.朱茂桃;钱洋;顾娅欣基于Kriging模型的车门刚度和模态优化 2013(11)20.Choi W S;Park G J Structural optimization using equivalent static loads at all time intervals 2002(19-20)21.Jeong S;Yi S;Kan C Structural optimization of an automobile roof structure using equivalent static loads 2008(11)22.Shimoda M;Tsuji J Shape optimization for weight reduction of automotive shell structures subject to a strength constraint.SAE Technical Paper,2007-01-372023.方剑光;高云凯;王婧人基于网格变形技术的白车身多目标形状优化 2012(24)24.Bendsφe M P Optimal shape design as a material distribution problem 1989(04)25.Yang R J;Chahande A I Automotive applications of topology optimization 1995(3-4)26.Yang R J;Chuang C;Che X New applications of topology optimization in automotive industry 2000(01)27.Baskin D M;Reed D B;Seel T N A case study in structural optimization of an automotive body-in-white design.SAE Tech Paper,2008-01-088028.SU Ruiyi;GUI Liangjin;FAN Zijie Truss Topology Optimization Using Genetic Algorithm with Individual Identification 200929.SU Ruiyi;GUI Liangjin;FAN Zijie Topology and sizing optimization of truss structures using adaptive genetic algorithm with node matrix encoding 200930.SU Ruiyi;WANG Xu;GUI Liangjin Multi-objective topology and sizing optimization of truss structures based on adaptive multi-island search strategy 2011(02)31.Sobieski J Optimization by decomposition:a step from hierarchic to non-hierarchic systems 198832.Kroo I;Altus S;Braun R Multidisciplinary optimization methods for aircraft preliminary design 199433.Kim H M;Michelena N F;Papalambros P Y Target cascading in optimal system design 2003(03)34.De Weck O;Agte J;Sobieski J State-of-the-art and future trends in multidisciplinary design opti-mization 200735.苏瑞意;桂良进;吴章斌大客车车身骨架多学科协同优化设计 2010(018)36.Michelena N;Louca L;Kokkolaras M Design of an advanced heavy tactical trucks:A target cascading case study.SAE Tech Paper,2001-01-279337.Kim H M;Rideout D G;Papalambros P Y Analytical target cascading in automotive vehicle design 2003(03)38.赵迁;陈潇凯;林逸解析目标分流法在汽车多学科设计优化中的应用 2010(06)39.冯美斌汽车轻量化技术中新材料的发展及应用 2006(03)40.马鸣图;柏建仁汽车轻量化材料及相关技术的研究进展 2006(06)41.王利;陆匠心汽车轻量化及其材料的经济选用 2013(01)42.王广勇;王刚高强度钢在汽车轻量化中的应用 2011(01)43.桂良进;高付海;范子杰双相钢板料的单向拉伸断裂失效研究(Ⅰ)一数字图像相关技术试验 2010(02)44.高付海;桂良进;范子杰双相钢板料的单向拉伸断裂失效研究(Ⅱ)一弧长法非线性有限元分析 2010(03)45.GAO F;GUI L;Fan Z Experimental and Numerical Analysis of an In-Plane Shear Specimen Designed for Ductile Fracture Studies 2011(06)46.桂良进;高付海;范子杰先进高强度钢的断裂失效准则研究 2012(33)47.Sadagopan S Formability characterization of advanced high-strength steels48.Pickett AK;Pyttel T;Payen F Failure prediction for advanced crashworthiness of transportation vehicles 2004(07)49.Ducker Worldwide EAA Aluminium penetration in cars 201250.Hirsch Ju¨ rgen Aluminum in Innovative Light-Weight Car Design 2011(05)51.马鸣图;游江海;路洪洲汽车轻量化以及铝合金汽车板的应用 200952.詹志强铝合金汽车车身板应用现状及需求前景 201253.王丹铝合金汽车板应用及生产现状 2013(03)54.桂良进;范子杰;王青春泡沫填充圆管的轴向压缩能量吸收特性 2003(11)55.桂良进;范子杰;王青春泡沫填充圆管的动态轴向压缩吸能特性 2004(05)56.王青春;范子杰;桂良进泡沫铝填充帽型结构轴向冲击吸能特性的试验研究 2006(04)57.王青春;范子杰;桂良进中等应变率下泡沫铝的吸能特性 2005(06)58.WANG Q;FAN Z;SONG H Experimental and numerical analyses of the axial crushing behaviour of hat sections partially filled with aluminum foam 2005(05)59.WANG Q;FAN Z;GUI L A theoretical analysis for the dynamic axial crushing behaviour of aluminium foamfilled hat sections 2006(7-8)60.WANG Q;FAN Z;GUI L Theoretical analysis for axial crushing behaviour of aluminium foam-filled hat sections2007(04)61.Waurzyniak P Advanced materials in automotive:Newer steels,aluminum,magnesium,and other materials lead to more lightweight,economical vehicles 2009(03)62.Kulekci M K Magnesium and its alloys applications in automotive industry 2008(09)63.吴章斌;桂良进;范子杰AZ31B镁合金挤压板材力学性能的各向异性 2012(02)64.许江菱;钟晓萍;殷荣忠2011-2012年世界塑料工业 进展 2013(03)65.杨挺汽车工业中塑料材料应用的现状及展望 2013(05)66.ZHANG Ping;GUI Liangjin;FAN Zijie Finite element modeling of the quasi-static axial crushing of braided composite tubes 2013(01)67.ZHANG Ping;GUI Liangjin;FAN Zijie Crash energy absorption of braided composite tubes and its application in vehicle passive safety 201368.GUI Liangjin;ZHANG Ping;FAN Zijie Energy absorption properties of braided glass/epoxy tubes subjected to quasi-static axial crushing 2009(01)69.ZHANG Ping;GUI Liangjin;FAN Zijie An analytical model for predicting the elastic properties of triaxially braided composites 2009(15)70.张平;桂良进;范子杰三向编织复合材料弹性性能研究 2009(01)71.康万平;王宇;康蕾管件液压成型技术简述 2010(01)72.王习文;宗长富;郭立书管件液压成形技术及其在汽车零部件制造中的应用 2013(04)73.杨勇;徐峰;苏海波管件液压成形技术及其在副车架上的应用 2010(03) Hydroforming achieves vehicle weight and cost reduction says study 201275.Koca f da A;Sadtowska H Automotive component development by means of hydroforming 2008(03)ngerak N;Rout D K;Verma R Tube hydroforming in automotive applications 201477.陈杰管材内高压成形数值模拟与工艺研究 201378.李泷杲金属薄壁管液压成形应用基础研究 200779.任芝兰汽车用高强度钢的激光焊焊接性研究 2006(01)80.朱久发激光拼焊汽车板的应用现状与发展前景 2011(03)81.ROFIN Lasers in Automotive Industry 201482.Klaus L Laser Applications in the Automotive Industry 201183.Chen H C;Pinkerton J A Mistry,Gap-free fibre laser welding of Zn-coated steel on A1 alloy for light-weight automotive applications 2011(02)84.HYRCZA-MICHALSKA M;GROSMAN F The evaluate of laser welded tailor and tubular blanks formability for automotive vehicle elements stamping 2009(01)85.Sieben M;Brunnecker F Laser-Hybrid welding,an innovative technology to join automotive body parts 201086.Schimek M;Springer A;Kaierle S Laser-welded dissimilar steel-aluminum seams for automotive lightweight construction 201287.Vasilash G S VW Is Hot On Lasers 200488.Bea M;Brockmann R;Havrilla D Remote laser welding in automotive production 2011引用本文格式：范子杰.桂良进.苏瑞意.FAN Zijie.GUI Liangjin.SU Ruiyi汽车轻量化技术的研究与进展[期刊论文]-汽车安全与节能学报 2014(1)。
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ARTICLE in SURFACE ENGINEERING · FEBRUARY 2013
Impact Factor: 1.2 · DOI: 10.1179/1743294413Y.0000000127
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4 AUTHORS: Josef Sedláček Czech Tes: Plasma, Ceramics, CaTiO3, Permittivity, Resistivity
Introduction
In recent decades plasma spraying has become a well accepted coating method for metallic and ceramic materials and has been used in a variety of fields including electrical engineering.1,2 Plasma sprayed coatings are produced by introducing powder particles of a material into a plasma jet, which melts and propels them towards the substrate. Coating is formed as a result of the interaction between a droplet and the substrate or the previously deposited layers. The lamellar character of a body formed in this way induces a particular character of porosity.3 Besides the chemical and phase composition, the porosity is main factor affecting almost all of the mechanical, thermal and electric properties of coatings. Various works on dielectric properties of plasma sprayed titanate ceramics have been published,4,5,6 but there is a lack of research comparing plasma sprayed samples produced with different spray techniques. Such a study has got to be done with advantage employing CaTiO3 because it is a material well known and widely used as a dielectric in a sintered state. Dielectric behaviour of CaTiO3 is described in several comprehensive textbooks.7,8 A small drop of permittivity with frequency is reported there based on one source of the experimental data but an increase above 105 Hz by another source. Titanates, in general, form a wide ranging and important group of dielectric ceramics. CaTiO3 is often used in complex ceramic systems where its content
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环境资源英语词汇(2) 人为灾难Human-made disasters人类住区HUMAN SETTLEMENTS人类迁居Human migration人体健康HUMAN HEALTH住房规划Housing programmes住房需求Housing needs住房立法Housing legislation住房改善Housing improvements住房集资Housing finance住房密度Housing density医院废物Hospital wastes无家可归Homelessness历史遗址Historical sites高层建筑High-rise buildings健康立法Health legislation卫生设施Health facilities危险废物Hazardous wastes危险物质Hazardous substances生境破坏Habitat destruction温室气体Greenhouse gases温室效应Greenhouse effect草地火灾Grass fires政府建筑Government buildings全球变暖Global warming几何修正Geometric corrections地理投影Geographical projections性别问题Gender issues气体液化Gas liquefaction杀真菌剂Fungicides燃料酒精Fuel alcohol淡水资源Freshwater resources洪水监测Freshwater monitoring淡水恶化Freshwater degradation矿物燃料Fossil fuels林业立法Forestry legislation森林政府Forest policy森林管理Forest management森林火灾Forest fires森林保护Forest conservation食品运输Food transport食品贮藏Food storage食品科学Food science食品保存Food preservation食品辐照Food irradiation食品污染Food contamination食用色素Food colourants植物区系Flora渔业管理Fisheries management鱼类养殖Fish culture火、火灾Fire财政资助Financial assistance动物区系Fauna农业建筑Farm buildings计划生育Family planning专家系统Expert system挖掘堆积Excavation heaps蒸发作用Evaporation富营氧化Eutrophication流行病学Epidemiology环境冲突Environmental warfare环境定价Environmental valuation环境培训Environmental training环境术语Environmental terminology环境补贴Environmental subsidies环境统计Environmental statistics环境安全Environmental security环境政策Environmental policy环境规划Environmental planning环境监测Environmental monitoring环境过失Environmental misconduct环境管理ENVIRONMENTAL MANAGEMENT 环境责任Environmental liability环境信息ENVIRONMENTAL INFORMA TION 环境指标Environmental indicators环境影响Environmental impact环境教育Environmental education环境标准Environmental criteria环境犯罪Environmental crimes环境成本Environmental costs环境化学ENVIRONMENTAL CHEMISTRY环境意识Environmental awareness环境审计Environmental auditing环境评价Environmental assessment环境核算Environmental accounting环境事故Environmental accidents能源利用Energy use能源资源Energy resources能源生产Energy production能源过程Energy processes能源政策Energy policy能源效率Energy efficiency能源转换Energy conversion能源保护Energy conservation内分泌学Endocrinology紧急救援Emergency relief电子函件Electronic mail蓄电装置Electrical storage devices 电气工程Electrical engineering电力分配Electric power distribution 生态旅游Ecotourism经济规划Economic zoning经济计划Economic planning经济发展Economic development生态平衡Ecological balance生态标志Ecolabelling生态发展Ecodevelopment毒品滥用Drug abuse文件出错document lending区城供热District heating处置场所Disposal sites尸体处置Disposal of the dead灾难救援Disaster relief防灾准备Disaster preparedness二恶英Dioxins发展计划Development planning发展模式Development patterns发展合作Development cooperation 燃料脱硫Desulphurization of fuels 沙漠蝗虫Desert locusts脱盐工厂Desalination plants脱氮作用Denitrification森林砍伐Deforestation深海矿藏Deep sea deposits数据处理Data processing数据收集Data collection数据中心Data centre文化指标Cultural indicators作物废物Crop waste作物保护Crop protection坐标系统Coordinate system受控燃烧Controlled burning等高耕作Contour farming消费方式Consumption patterns建筑工程Construction works施工技术Construction technology谈水保护Conservation of freshwater 混合污染Composite pollution社区服务Community services社区参与Community participation 联络渠道Communication channels 商业噪音Commercial noise彩色组成Colour composition海岸侵蚀Coastal erosion沿海环境Coastal environments沿海开发Coastal development沿海地区Coastal areas服装工业Clothing industry无性繁殖Cloning气候问题Climatic issues气候变化Climatic change清洁技术Clean technologies土木工程Civil engineering色谱分析Chromatographic analysis 化学武器Chemical weapons化学工业Chemical industry化学肥料Chemical fertilizers化学工程Chemical engineering协商费用Charges negotiable水泥工业Cement industry灾难现象Catastrophic phenomena心脏病学Cardiology二氧化碳Carbon dioxide建成结构Built structures建筑技术Building technology建筑材料Building materials生育控制Birth control群落生境Biotopes生物技术Biotechnologies生物安全Biosafety生物质能Biomass energy生物武器Biological weapons生物资源Biological resources生物固氮Biological nitrogen fixation 生物指标Biological indicators生物降解Biodegradation生物化学Biochemistry双边协定Bilateral conventions饮料工业Beverage industry电池处理Battery disposal本底监测Baseline monitoring汽车停放Automobile parking自动检测Automatic detection视听演示Audio-visual presentation 大气过程Atmospheric processes大气降水Atmospheric precipitation 大气监测Atmospheric monitoring 大气模型Atmospheric models大气修正Atmospheric corrections 大气组成Atmospheric composition 大气成分Atmospheric components 大气环流Atmospheric circulation 大气化学Atmospheric chemistry节肢动物Arthropods干旱土地Arid lands北极地区Arctic region水生植物Aquatic plants水产养殖Aquaculture适用技术Appropriate technology 南极地区Antarctic region动物资源Animal resources动物营养Animal nutrition动物疾病Animal diseases动物习性Animal behaviour分析设备Analytical equipment分析化学Analytical chemistry厌氧过程Anaerobic processes两栖动物Amphibians制铝工业Aluminium industry飞机噪音Aircraft noise空气质量Air quality空气污染Air pollution农业林学Agroforestry农业废物Agricultural wastes农业储藏Agricultural storage农业生产Agricultural production 农业方式Agricultural practices农业害虫Agricultural pests农业方法Agricultural methods农业管理Agricultural management农业立法Agricultural legislation农用土地Agricultural land农业设备Agricultural equipment农业工程Agricultural engineering植树造林Afforestation需氧过程Aerobic processes行政边界Administrative boundaries入海通道Access to the sea水的再利用Water reuse水资源开发Water resources development 水资源保护Water resources conservation 废物最少化Waste minimization废物处置税Waste disposal taxes矢量到光栅V ector to raster对流层臭氧Tropospheric ozone废物，垃圾Trash临时避难所Temporary shelter合成洗涤剂Synthetic detergents可持续发展Sustainable development次国家边界Sub-national boundaries建筑业标准Standards for building industry 土壤盐碱化Soil salination屠宰场废物Slaughterhouse waste工农业选址Siting of industry污水处理厂Sewage treatment plants沉积物运移Sediment transport沉积物移动Sediment mobilization海洋排泄口Sea outfall海平面上升Sea level rise材料再利用Reuse of materials可再用容器Reusable containers可再生资源Renewable resources可再生能源Renewable energy sources相关数据库Relational database区域性公约Regional conventions回收的材料Recycled materials光栅到矢量Raster to vector放射性物质Radioactive substances放射性污染Radioactive contamination装配式房屋Prefabricated buildings聚合物废物Polymer wastes污染物路径Pollutant pathways污染物监测Pollutant monitoring污染物浓度Pollutant levels污染物分布Pollutant distribution污染物分析Pollutant analysis植物生理学Plant physiology植物遗传学Plant genetics物理海洋学Physical oceanography摄影测绘学Photogrammetry光化学效应Photochemical effects光化学试剂Photochemical agents石油地质学Petroleum geology杀虫剂路径Pesticide pathways病虫害控制Pest management泥炭、泥煤Peat病原生物体Pathogenic organisms有机磷化物Organophosphorous compounds有机卤化物Organohalogen compounds采矿地质学ORGANISA TIONAL A TTRIBUTES 有机物污染Organic pollutants盘尾丝虫病Onchocerciasis营养与保健Nutrition and health care核研究中心Nuclear research centres无污染能源Non-polluting energy sources非电离辐射Non-ionizing radiation非政府组织Non-governmental organization资源净损耗Net resource depletion航运的危害Navigational hazards来源的性质Nature of the source天然气开采Natural gas extraction天然气勘探Natural gas exploration国家保护区National reserves多媒体技术Multimedia technology分子生物学Molecular biology采矿地质学Mining geology微气候影响Microclimate effects微生物资源Microbial resources机械工程学Mechanical engineering污染沉积物Marine sediments海洋地质学Marine geology海洋保护区Marine conservation areas海洋生物学Marine biology图书馆服务Library services无脊椎动物Invertebrates国际标准化International standardization无机污染物Inorganic pollutants信息工具包Information kit婴儿死亡率Infant mortality工业排放物Industrial emissions文件编索引Indexing of documentation 污染物鉴别Identification of pollutants 溶液培养学Hydroponics水文地理学Hydrography碳氢化合物Hydrocarbon compounds人体生理学Human physiology人体病理学Human pathology人类的疾病Human diseases人体生物学Human biology高蛋白食品High protein foods全球性公约Global conventions工艺地质学Geotechnology地球物理学Geophysics遗传工程学Genetic engineering气象色谱法Gas chromatography淡水生物学Freshwater biology食品工艺学Food technology食品添加剂Food additives河口海洋学Estuarine oceanography河口保护区Estuarine conservation areas 河口生物学Estuarine biology人机工程学Ergonomics环境经济学Environmental economics 应急避难所Emergency shelter饮用水处理Drinking water treatment饮用水供应Drinking water supply甲壳纲动物Crustaceans污染的土壤Contaminated soil污染的土地Contaminated land化学海洋学Chemical oceanography南美锥虫病Chagas'' disease公告牌系统Bulletin board system生物多样性Biological diversity生物伦理学Bioethics生物气候学Bioclimatology大气物理学Atmospheric physics大气颗粒物Atmospheric particulates水生微生物Aquatic microorganisms动物生理学Animal physiology动物遗传学Animal genetics动物生态学Animal ecology空气污染物Air pollutants农业气象学Agrometeorology农用化学品Agrochemicals农业经济学Agricultural economics农业生态学Agricultural ecology林地生态系统Woodland ecosystems野生生物生境Wildlife habitats野生生物保护Wildlife conservation湿地生态系统Wetlands ecosystems人工影响天气Weather modification废物土地处置Waste disposal in the ground废物转化技术Waste conversion techniques废物同化处置Waste assimilation capacities杀虫剂的使用Utilization of pesticides热带生态系统Tropical ecosystems杀虫剂的毒性Toxicity of pesticides陆地生态系统TERRESTRIAL ECOSYSTEMS陆地生物资源Terrestrial biological resources温带生态系统Temperate ecosystems合成纺织纤维Synthetic textile fibres结构调整计划Structural adjustment programs统计信息系统Statistical information system固体废物处置Solid waste disposal药物的副作用Side effects of pharmaceutical drugs 污水处理系统Sewage treatment systems建筑安全标准Safety standards for buildings道路交通工程Road traffic engineering河流流域开发River basin development信息查询系统Referral information system供查询的信息Referral information受保护的物种Protected species事先知情同意Prior informed consent污染控制技术Pollution control technology污染控制法规Pollution control regulations污染治理设备Pollution abatement equipment污染物的影响Pollutant effects极地生态系统Polar ecosystems石油资源保护Petroleum resources conservation城区发展模式Patterns of urban growth有机硅化合物Organosilicon compounds近海石油钻探Offshore oil drilling不可再生资源Non-renewable resources不可再生能源Non-renewable energy resources社区改善计划Neighbourhood improvement schemes 自然排水系统Natural drainage systems国家保护计划National conservation programmes城市配水系统Municipal water distribution systems多谱线扫描器Multispectral scanner山地生态系统Mountain ecosystems杀虫剂的代谢Metabolism of pesticides海洋资源保护Marine resources conservation海洋生态系统Marine ecosystems本地建筑材料Local materials for building海洋生物资源Living marine resources核破坏的责任Liability for nuclear damages土地利用规划Land use planning土地使用分类Land use classification陆地哺乳动物Land mammals土地承载能力Land carrying capacity岛屿生态系统Island ecosystems国际河流流域International river basins国际环境关系International environmental relations信息基础设施Information infrastructure信息交流中心Information clearing-house粮食虫害传染Infestation of food作物虫害传染Infestation of crops工业生产统计Industrial production statistics工业生产过程Industrial processes空内空气污染Indoor air pollution人类住区管理Human settlements management住房质量标准Housing quality standards高原生态系统Highland ecosystems污染物的危害Hazards of pollutants绿色财政手段Green fiscal instruments草地生态系统Grassland ecosystems政府环境开支Government environmental expenditures 地理信息系统Geographic information systems淡水生态系统Freshwater ecosystems森林资源评估Forest resource assessment森林生态系统Forest ecosystems用火安全要求Fire safety requirements农家场院废物Farmyard waste河口生态系统Estuarine ecosystems环境破坏行为Environmental vandalism环境股票交易Environmental stock exchange环境风险评估Environmental risk assessment环境质量标准Environmental quality standards环境质量指标Environmental quality indicators环境管理指标Environmental management indicators环境激励措施Environmental incentives环境影响评价Environmental impact assessment环境健康危害Environmental health hazards环境经济问题Environmental economic issues环境应急计划Environmental contingency planning 能源利用方式Energy utilization patterns濒危植物物种Endangered plant species濒危动物物种Endangered animal species应急减灾措施Emergency relief measures电子信息网络Electronic information network经济管理手段Economic management instruments 流离失所人员Displaced persons灾难清理作业Disaster clean-up operations沉降的颗粒物Deposited particulate matter决策支持系统Decision-support system数据记录技术Data recording techniques基因资源保护Conservation of genetic resources寒带生态系统Cold zone ecosystems沿海生态系统Coastal ecosystems化学污染清除Chemical decontamination生物技术问题Biotechnological issues生物圈保护区Biosphere reserves生物地球化学Biogeochemistry生物化学过程Biochemical processes文献目录信息Bibliographic information海底生态系统Benthic ecosystems基本食物要求Basic food requirements北极生态系统Arctic ecosystems水上娱乐活动Aquatic recreational amenities水生哺乳动物Aquatic mammals南极生态系统Antarctic ecosystems空中交通规则Air traffic regulations空气质量管理Air quality management农业生物技术Agricultural biotechnologies本地资源的利用Utilization of local resources危险物质的运输Transport of hazardous materials 可交易的许可证Tradeable permits可持续发展指标Sustainable development indicators 亚热带生态系统Sub-tropical ecosystems水生贝壳类动物Shellfish放射性废物管理Radioactive waste management放射性示踪技术Radioactive tracer techniques放射性污染清除Radioactive decontamination资源的定价政策Pricing policies of resources污染者付费原则Polluter-pays principle污染物来源鉴别Pollutant source identification规划的城区发展Planned urban development物理－化学过程Physico-chemical processes外激素，信息素Pheromones药理学，药物学Pharmacology杀虫剂标准控制Pesticide control standards杀虫剂的持久性Persistence of pesticides在交换的基础上On exchange basis非高峰时间工作Off-peak working非高峰时间通勤Off-peak commuting食品的营养价值Nutritive value of food一般情况下免费Normally without charge突变微生物释放Mutated microorganisms release机动车辆排放物Motor vehicle emissions以绿色标志促销Marketing with green labelling丢弃物，废气物Litter海洋事故的责任Liability for marine accidents因特网查询服务Internet search service环境成本内在化Internalisation of environmental costs工业的或商业的Industrial or commercial人体接触污染物Human exposure to pollutants资源的地埋分布Geographic distribution of resources危险废物的出口Export of hazardous wastes发展中国家债务Developing countries debt废物的化学处理Chemical treatment of waste测量仪器的标定Calibration of measuring equipment建成的排水系统Built drainage systems害虫的生物控制Biological control of pests动物粪便作燃料Animal dung as fuel适应性强的物种Adaptable species野生生物种群统计Wildlife population statistics人类疾病传染媒介V ectors of human diseases热带森林生态系统Tropical forest ecosystems贸易对环境的影响Trade impact on environment受监视的图象分类Supervised image classification信息的选择性传播Selective dissemination of information 植物的选择性繁殖Selective breeding of plants动物的选择性繁殖Selective breeding of animals公众对土地的获取Public access to land难降解有机污染物Persistent organic pollutants永久冻土生态系统Permafrost ecosystems对破坏环境的惩罚Penalties for environmental damage污染物的长期效应Long-term effects of pollutants因特网服务提供商Internet service provider杀虫剂的相互作用Interaction of pesticides图书馆之间的借贷Inter-library loan图象处理数字系统Image processing digital systems与地学有关的信息Geo-referenced information与地理相关的数据Geo-referenced data固定的收费时间表Fixed schedule of charges与环境有关的疾病Environmentally related diseases环境影响状报告书Environmental impact statement环境健康影响评价Environmental health impact assessment数字图象处理技术Digital image processing techniques按回收成本为基础Cost recovery basis文献目录信息系统Bibliographic information system干旱地区生态系统Arid land ecosystems污染防治激励措施Antipollution incentives飞机发动机排放物Aircraft engine emissions空气－水相互作用Air-water interaction气溶胶，气雾剂Aerosols生物体的意外释放Accidental release of organisms未被监视的图象分类Unsupervised image classification有毒物质的协同效应Synergistic effects of toxic substances半干旱地区生态系统Semi-arid land ecosystems从废料中提取的燃料Refuse derived fuels模型制作，模型设计Modelling湖沼学，淡水生物学Limnology地理信息系统实验室GIS laboratory人类住区的环境方面Environmental aspects of human settlements生物多样性和保护区Biological diversity and protected areas在人体组织中的积累Accumulation in body tissues国际性重要的失态系统Internationally important ecosystems与健康有关的生物技术Health-related biotechnologies光盘只读存储查询服务CD-ROM search service危险废物运输的事先通告Prior notification for hazardous waste transport地理信息系统的数字技术GIS digital techniques地理信息系统的数字系统GIS digital systems地理信息系统的数字格式GIS digital formats生物技术的社会－经济影响Socio-economic impact of biotechnologies人类住区的社会－经济方面Socio-economic aspects of human settlements已定价值的生态系统组成部分valued ecosystem components温带生态系统和寒带生态系统Temperate ecosystems and cold zone ecosystems 代谢（作用），新陈代谢（作用）Metabolism大气A TMOSPHERE大气组成Atmospheric composition空气质量Air quality大气化学Atmospheric chemistry大气成分Atmospheric components大气颗粒物Atmospheric particulates二氧化碳Carbon dioxide温室气体Greenhouse gases氧气Oxygen臭氧层Ozone layer大气过程Atmospheric processes空气－水相互作用Air-water interaction 大气环流Atmospheric circulation大气降水Atmospheric precipitation碳循环Carbon cycle蒸发作用Evaporation降水增加Precipitation enhancement降雨Rainfall太阳辐射Solar radiation蒸腾作用Transpiration风Winds空气污染Air pollution酸雨Acid rain空气污染物Air pollutants氯氟碳Chlorofluorocarbons沉降的颗粒物Deposited particulate matter 飞灰Fly ash雾Fog薄烟Haze空内空气污染Indoor air pollution烟雾Smog气候问题Climatic issues农业气象学Agrometeorology气候Climate气候变化Climatic change气候带Climatic zones干旱Drought全球变暖Global warming温室效应Greenhouse effect湿度Humidity微气候影响Microclimate effects海平面上升Sea level rise人工影响天气Weather modification岩石圈LITHOSPHERE固态地球Solid Earth洞穴Caves地震活动Seismic activity地震监测Seismic monitoring火山V olcanoes风蚀Wind erosion陆地生态系统TERRESTRIAL ECOSYSTEMS 土壤Soils农用土地Agricultural land碱地Alkali lands污染的土地Contaminated land污染的土壤Contaminated soil沙坑Gravel pits荒地Heath lands土地承载能力Land carrying capacity土地污染Land pollution土地开垦Land reclamation土地恢复Land restoration土地使用分类Land use classification边缘土地Marginal lands沙石开采Sand extraction沉积Sedimentation土壤潜力Soil capabilities土壤保持Soil conservation土壤污染Soil contamination土壤退化Soil degradation土壤侵蚀Soil erosion土壤改良Soil improvement土壤盐碱化Soil salination水蚀Water erosion干旱地区生态系统Arid land ecosystems干旱土地Arid lands沙漠化Desertification抗旱Drought control旱作Dry farming沙丘固定Sand dune fixation沙丘Sand dunes半干旱地区生态系统Semi-arid land ecosystems 森林生态系统Forest ecosystems植树造林Afforestation针叶林Coniferous forests森林砍伐Deforestation森林保护Forest conservation森林火灾Forest fires草地火灾Grass fires绿化带Greenbelts本地森林Indigenous forests再造林Reafforestation植被恢复Revegetation亚热带生态系统Sub-tropical ecosystems温带森林Temperate forests温带林地Temperate woodlands树木Trees热带生态系统Tropical ecosystems热带森林Tropical forests热带森林生态系统Tropical forest ecosystems林地生态系统Woodland ecosystems温带生态系统和寒带生态系统Temperate ecosystems and cold zone ecosystems 南极生态系统Antarctic ecosystems南极地区Antarctic region北极生态系统Arctic ecosystems北极地区Arctic region寒带生态系统Cold zone ecosystems草地生态系统Grassland ecosystems永久冻土生态系统Permafrost ecosystems极地生态系统Polar ecosystems温带生态系统Temperate ecosystems山地生态系统Mountain ecosystems高原生态系统Highland ecosystems登山运动Mountaineering湿地生态系统Wetlands ecosystems红树沼泽Mangrove swamps水禽Waterfowl水涝地Waterlogged lands流域管理Watershed management水边开发Waterside development生物多样性和保护区Biological diversity and protected areas适应性强的物种Adaptable species藻类Algae两栖动物Amphibians动物习性Animal behaviour动物资源Animal resources节肢动物Arthropods生物多样性Biological diversity生物资源Biological resources生物圈保护区Biosphere reserves群落生境Biotopes鸟类Birds植物园Botanical gardens基因资源保护Conservation of genetic resources生态平衡Ecological balance濒危动物物种Endangered animal species濒危植物物种Endangered plant species河口保护区Estuarine conservation areas动物区系Fauna植物区系Flora食物链Food chain捕猎Hunting无脊椎动物Invertebrates陆地哺乳动物Land mammals哺乳动物Mammals海洋保护区Marine conservation areas微生物Microorganisms移栖种Migratory species国家公园National parks国家保护区National reserves寄生生物Parasites愉猎Poaching灵长目Primates保护区Protected areas受保护的物种Protected species爬行动物Reptiles陆地生物资源Terrestrial biological resources 植被V egetation杂草Weeds野生生物Wildlife野生生物保护Wildlife conservation野生生物生境Wildlife habitats动物园Zoological gardens细菌Bacteria酶Enzymes真菌Fungi基因库Gene banks种质Germ plasm微生物资源Microbial resources原生生物Protozoa病毒V iruses酵母Y easts生物技术问题Biotechnological issues农业生物技术Agricultural biotechnologies生物伦理学Bioethics生物安全Biosafety生物技术Biotechnologies无性繁殖Cloning与健康有关的生物技术Health-related biotechnologies诱变剂Mutagens突变微生物释放Mutated microorganisms release突变体Mutants繁殖控制Reproductive manipulationDNA重组技术Recombinant DNA technology动物的选择性繁殖Selective breeding of animals植物的选择性繁殖Selective breeding of plants生物技术的社会－经济影响Socio-economic impact of biotechnologies 致畸剂Teratogens淡水FRESHWA TER淡水资源Freshwater resources谈水保护Conservation of freshwater水坝Dams冰Ice湖泊Lakes自然排水系统Natural drainage systems河流流域开发River basin development河流Rivers雪Snow地下水Subterranean water地表水Surface waters水资源保护Water resources conservation水资源开发Water resources development淡水生态系统Freshwater ecosystems集水区Catchment areas国际河流流域International river basins湖泊流域Lake basins池塘尾渣Ponds tailings河流流域River basins淡水恶化Freshwater degradation河流污染River pollution径流Run-off沉积物移动Sediment mobilization沉积物运移Sediment transport沉积盆地Sedimentary basins渗漏Seepage凤眼蓝Water hyacinth水污染Water pollution水的盐化Water salination饮用水供应Drinking water supply脱盐Desalination饮用水Drinking water饮用水处理Drinking water treatment城市配水系统Municipal water distribution systems 农村供水Rural water supply污水处理厂Sewage treatment plants水泵Water pumps水处理Water treatment水井Water wells海洋环境MARINE ENVIRONMENTS海洋生态系统Marine ecosystems藻花Algal bloom海底生态系统Benthic ecosystems海洋污染Marine pollution污染沉积物Marine sediments海洋环境Ocean circulation洋流Ocean currents海洋Oceans海洋温度Ocean temperature赤潮Red tide海平面Sea level潮,潮汐Tides沿海生态系统Coastal ecosystems群岛Archipelagoes沿海地区Coastal areas沿海开发Coastal development沿海环境Coastal environments海岸侵蚀Coastal erosion疏浚Dredging河口生态系统Estuarine ecosystems岛屿生态系统Island ecosystems小岛屿Small islands海洋生物资源Living marine resources水生哺乳动物Aquatic mammals水生微生物Aquatic microorganisms水生植物Aquatic plants珊瑚礁Coral reefs甲壳纲动物Crustaceans鱼类Fish海洋资源保护Marine resources conservation软体动物Molluscs水生贝壳类动物Shellfish环境管理ENVIRONMENTAL MANAGEMENT 资源管理Resources management深海矿藏Deep sea deposits森林管理Forest management森林政府Forest policy资源的地埋分布Geographic distribution of resources土地价值Land values矿产资源Mineral resources国家保护计划National conservation programmes自然资源Natural resources自然保护Nature conservation不可再生资源Non-renewable resources资源净损耗Net resource depletion矿床Ore deposits石油资源保护Petroleum resources conservation可再生资源Renewable resources资源估价Resource appraisal资源保护Resource conservation海底开发Sea bed exploitation海底采矿Sea bed mining本地资源的利用Utilization of local resources环境规划Environmental planning发展合作Development cooperation发展计划Development planning生态发展Ecodevelopment经济发展Economic development经济计划Economic planning环境核算Environmental accounting环境审计Environmental auditing环境健康影响评价Environmental health impact assessment 环境影响Environmental impact环境影响评价Environmental impact assessment环境影响状报告书Environmental impact statement环境指标Environmental indicators环境政策Environmental policy环境风险评估Environmental risk assessment财政资助Financial assistance土地利用规划Land use planning环境管理指标Environmental management indicators环境质量指标Environmental quality indicators试验项目Pilot projects政策规划Policy planning施压集团Pressure groups区域规划Regional planning自助计划Self-help programmes工农业选址Siting of industry社会调查Social surveys发展状况Status of development可持续发展Sustainable development可持续发展指标Sustainable development indicators技术评价Technology assessment运输计划Transport planning环境经济问题Environmental economic issues环境定价Environmental valuation环境成本Environmental costs外部Externalities重置成本Replacement costs贸易对环境的影响Trade impact on environment已定价值的生态系统组成部分valued ecosystem components 经济管理手段Economic management instruments成本-效益分析Cost-benefit analysis发展中国家债务Developing countries debt环境股票交易Environmental stock exchange政府环境开支Government environmental expenditures绿色财政手段Green fiscal instruments环境成本内在化Internalisation of environmental costs以绿色标志促销Marketing with green labelling资源的定价政策Pricing policies of resources结构调整计划Structural adjustment programs税收差别Tax differentiation可交易的许可证Tradeable permits人类住区HUMAN SETTLEMENTS人类住区管理Human settlements management建成区Built-up areas经济规划Economic zoning用火安全要求Fire safety requirements历史遗址Historical sites住房改善Housing improvements住房需求Housing needs住房规划Housing programmes住房质量标准Housing quality standards工业区Industrial areas非高峰时间工作Off-peak working办公室Offices城区发展模式Patterns of urban growth规划的城区发展Planned urban development再建房屋Rehousing租赁房屋Rental housing居民区Residential areas建筑安全标准Safety standards for buildings商店Shops建筑业标准Standards for building industry城区设计Urban design建成结构Built structures桥梁Bridges建筑材料Building materials建筑物Buildings建筑技术Building technology施工技术Construction technology建筑工程Construction works农业建筑Farm buildings政府建筑Government buildings高层建筑High-rise buildings工业建筑Industrial buildings本地建筑材料Local materials for building拖车住房Mobile homes核研究中心Nuclear research centres装配式房屋Prefabricated buildings结构Structures隔热Thermal insulation基础设施Infrastructure通道Access roads水上娱乐活动Aquatic recreational amenities汽车停放Automobile parking建成的排水系统Built drainage systems电力分配Electric power distribution公共花园Public gardens公路Highways空地Open spaces管道Pipelines运动场Playgrounds公园Public parks公用事业Public utilities道路建设Road construction道路养护Road maintenance体育设施Sports facilities电信Telecommunications运输系统Transport systems隧道Tunnels城市供水Urban water supply公共服务Public services人类住区的社会－经济方面Socio-economic aspects of human settlements 生育控制Birth control社区服务Community services社区参与Community participation通勤Commuting消费方式Consumption patterns文化指标Cultural indicators发展模式Development patterns残疾人Disabled persons毒品滥用Drug abuse生态旅游Ecotourism计划生育Family planning性别问题Gender issues无家可归Homelessness住房集资Housing finance人类迁居Human migration人口Human population人权Human rights土地分配Land allotment生活方式Lifestyles低价住房Low-cost housing流动工人Migrant workers少数民族Minorities社区改善计划Neighbourhood improvement schemes新社区New communities流浪者Nomads非高峰时间通勤Off-peak commuting公共卫生Public health种族关系Race relations娱乐Recreation农村地区Rural areas环境卫生Sanitation社会指数Social indicators社会-经济因素Socio-economic factors旅游Tourism旅行Travel贫困阶层Under-privileged people城市地区Urban areas城区改造Urban renewal城区压力Urban stress妇女地位Women status人类住区的环境方面Environmental aspects of human settlements 空调Air conditioning尸体处置Disposal of the dead区城供热District heating住房密度Housing density过度拥挤Overcrowding难民Refugees旅游设施Tourist facilities城市衰败Urban decay农业AGRICULTURE农业方式Agricultural practices农业设备Agricultural equipment农业管理Agricultural management农业方法Agricultural methods农业害虫Agricultural pests农业生产Agricultural production农业储藏Agricultural storage动物疾病Animal diseases动物营养Animal nutrition养蜂业Apiculture水产养殖Aquaculture害虫的生物控制Biological control of pests 生物固氮Biological nitrogen fixation堆肥Composts等高耕作Contour farming受控燃烧Controlled burning作物保护Crop protection挽畜Draught animals鱼类养殖Fish culture渔业管理Fisheries management谷物Grains作物虫害传染Infestation of crops粮食虫害传染Infestation of food灌溉Irrigation灌溉渠Irrigation canals灌溉农业Irrigation farming天然肥料Natural fertilizers有机农业Organic farming病虫害控制Pest management杀虫剂标准控制Pesticide control standards 植物病害Plant diseases家禽饲养Poultry farming林农轮作Shifting cultivation树木苗圃Tree nurseries滴灌Trickle irrigation农工业Agro-industry畜产品Animal products饮料工业Beverage industry酿造业Brewing industry蒸馏业Distilling industry食品辐照Food irradiation。
国外课件-natural materials,自然材料,仿生
Course Learning Objectives
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Understand the diverse range of nature’s materials, their complex hierarchical structure and their unique engineering properties Critically compare engineering and nature's solution to the structural design of composites materials Understand some of the issues and methodologies involved in the design of composites based biomaterials
Synthetic Composites: Architectures
6 M. Ashby / Scripta Materialia 68 (2013) 4–7
Matrix
Reinforcement
Unidirectional
Laminates
Short fiber
Particulate
F o am c e l l
§ Structure and mechanical properties, Marc Andre´ Meyers *, Po-Yu Chen, Albert Yu-Min Lin, and Yasuaki Seki, Progress in Materials Science 53 (2008) 1–206 § Cellulose and collagen: from fibres to tissues, Peter Fratzl, Current Opinion in Colloid and Interface Science 8 (2003) 32–39
Comments on ‘‘Design of aluminium boom and arm for an excavator”
Comments on ‘‘Design of aluminium boom and arm for an excavator”
ˇnjak ⇑ Srd an M. Bos
Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11120 Belgrade 35, Serbia Received 26 June 2011; received in revised form 18 September 2011; accepted 22 September 2011 Available online 13 October 2011
⇑ Tel.: +381 11 3370831; fax: +381 11 3370364.
E-mail address: sbosnjak@mas.bg.ac.rs
The BE WD weight reduction and installment of a bigger bucket may lead to machine performances decreasing due to the complexity of WD synthesis. Namely, as the effect of the WD weight reduction, the maximal breakout force will be reduced as well, and that fact prevents the realization of a designed soil chip thickness. In that case, and in order to excavate the same volume of soil, the total number of cycles needs to be increased, which inevitably leads to the decrease of machine capacity.