北京交通大学2002年硕士研究生机械原理真题
机械原理801考研真题_填空,选择,简答题
填空题1．由Ｍ个构件组成的复合铰链应包括_____个运动副。
【武汉科技大学】2．在平面中,不受约束的构件自由度数等于_____，两构件组成移动副后的相对自由度等于_____。
【武汉理工大学】3．在机构中按给定的已知运动规律运动的构件称为_____；使机构的位置得以确定必须给定的独立广义坐标的数目称为是_____；为了使机构具有确定的运动，应使_____。
【西北工业大学】4．高副低代必须满足的条件是_____。
【青岛大学2010】5．运动链与机构的区别是_____。
【华东理工大学2005】6．根据机构的组成原理，任何机构都可以看成是由_____、_____以及_____所组成。
【重庆大学2004】7．铰链五杆机构是_____级机构【湖南大学2005】8．相对瞬心与绝对瞬心的相同点是_____，不同点是_____；在由Ｎ个构件组成的机构中，有_____个相对瞬心，有_____个绝对瞬心。
【西北工业大学】9．速度瞬心是两构件上的瞬时相对速度为_____，瞬时绝对速度_____的重合点。
【山东大学2005】10．下图所示两种情况下，载荷Ｑ及摩擦系数ｆ均相同，则转动件１时所需力矩为Ｍ１_____Ｍ２。
（填＜、＝或＞）。
【清华大学】11．移动副的自锁条件是_____；转动副的自锁条件是_____；从效率的观点出发，机械的自锁条件是_____。
【哈尔滨工业大学2004】12．下两图所示转子中，Ｓ为总质心，图１中的转子具有_____不平衡，图２中的转子具有_____不平衡。
【哈尔滨工业大学2004】13．质径积是指转子的_____与_____的乘积；残余不平衡质径积相同，但质量不同的转子，质量_____的转子的平衡精度高。
【湖南大学2005】14．某机器主轴平均角速度ωｍ＝１００ｒａｄ／ｓ，机器运转的速度不均匀系数δ＝０．０５，则该机器的最大角度ωｍａｘ等于_____ｒａｄ／ｓ，最小角速度ωｍｉｎ等于_____ｒａｄ／ｓ。
2002年川大试题
四川大学2002年攻读硕士学位研究生入学考试试题考试科目：机械设计科目代号：567#适用专业：机械制造及其自动化、机械电子工程、机械设计及理论（试题共6页）（答案必须写在试卷上，写在试题上不给分）--------------------------------------------------------------------------一、单项选择：将下列各题的正确号码填在横线上。
（每题2分，共20分）1、受拉螺栓联接若螺栓所受预紧力为F'，在受轴向工作载荷F时，其剩余预紧力为F"，则螺栓所受的总拉力F。
为。
（1）F0=F'+F；（2）F0=F'+F"+F；（3）F0=F+F"；（4）F0=F"+F'2、对于受循环变应力作用的零件，影响疲劳强度的主要因素是。
（1）最大应力；（2）平均应力；（3）应力幅；（4）最小应力3、链传动的瞬时传动比若要等于常数，则它的主要条件是。
（1）z2=z1；（2）z2=z1，且中心距α是链节距p的整数倍。
（3）z2=3z1；（4）大链轮齿数z z是小链齿数z1的整数倍。
4、减速蜗杆传动中，用来计算传动比i是错误的。
（1）i=w1/w2；（2）i=d2/d1；（3）i=n1/n2；（4）i=z2/z15、花键静联接的强度主要取决于强度。
（1）齿根剪切；（2）齿侧接触；（3）齿根弯曲；（4）齿侧挤压6、滑动轴承的条件性计算中，限制PV值是为了。
（1）防止加速磨损；（2）防止过度磨损；（3）防止轴承温升过高；（4）防止出现过大的摩擦阻力矩。
7、配对齿轮副1、2的工作接触应力σH1、σH2之间的关系为。
（1）仅节点处σH1=σH2；（2）任意啮合位置处σH1=σH2；（3）σH1≥σH2；（4）σH1≤σH28、齿轮的弯曲强度，当，则齿根弯曲强度增加。
（1）模数不变，齿数增多时；（2）模数不变，中心距增大时；（3）齿数不变，模数加大时；（4）模数不变，齿轮直径加大时。
机械原理考研真题答案大全及解析
机械原理考研真题答案大全及解析是考研机械类专业的一门重要课程，也是考生们备考过程中需要重点关注的内容之一。
考试真题的答案及其解析是考生们复习备考的关键之一，下面将为大家整理一份考研真题答案大全及解析，希望能够对考生们有所帮助。
一、选择题1. 中，以下哪个定律在解题过程中往往起到重要作用？A. 力的合成定律B. 牛顿第一定律C. 动能定理D. 能量守恒定律答案：A. 力的合成定律解析：在中，力的合成定律是非常基础且常用的定律之一。
它可以帮助我们解决力的合力、分解以及力的方向等问题。
因此，在解题过程中使用合理的力的合成定律是非常重要的。
2. 关于静力学平衡的条件，以下说法正确的是：A. 物体处于匀速直线运动时称为动力学平衡B. 物体受到的合力和合力矩都为零时称为静力学平衡C. 物体受到的合力和合力矩都不为零时称为静力学平衡D. 物体受到的合力为零，合力矩不为零时称为静力学平衡答案：B. 物体受到的合力和合力矩都为零时称为静力学平衡解析：物体处于匀速直线运动时称为动力学平衡，物体受到的合力和合力矩都为零时称为静力学平衡。
物体受到的合力为零，在平衡状态下物体的加速度为零，即为匀速直线运动。
二、填空题1. 在力的合成中，合力的大小等于__________的矢量和。
答案：各个力解析：力的合成是指将多个力合成为一个力的过程，合力的大小等于各个力的矢量和。
2. 以下哪个定律可以用于解决物体匀加速直线运动的问题？答案：牛顿第二定律解析：牛顿第二定律描述了物体在外力作用下的加速度与受力之间的关系，可以用于解决物体匀加速直线运动的问题。
三、计算题1. 一根长度为L的均匀细棒，质量为M，沿着竖直方向平放在光滑的桌面上，现有一质点质量为m，位于棒的右端点。
求质点对棒的压力。
答案：压力P = (M+m)g*L/(4L)解析：首先根据重力的性质，质点m对棒的作用力大小为mg。
其次，在桌面上，质点m的重力可以通过细棒传递到桌面上，即细棒对质点的作用力和重力相等。
2002年考研真题及解析
2002年全国攻读硕士学位研究生入学考试英语试题Section I Use of EnglishDirections：Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C OR D on ANSWER SHEET 1. (10 points)Comparisons were drawn between the development of television in the 20th century and the diffusion of printing in the 15th and 16th centuries. Yet much had happened 1 . As was discussed before, it was not 2 the 19th century that the newspaper became the dominant pre-electronic_ 3 _ ，following in the wake of the pamphlet and the book and in the 4 of the periodical. It was during the same time that the communications revolution 5 up, beginning with transport, the railway, and leading 6 through the telegraph, the telephone, radio, and motion pictures 7 the 20th century world of the motor car and the air plane. Not everyone sees that Process in 8 . It is important to do so.It is generally recognized, 9 , that the introduction of the computer in the early 20th century,10 by the invention of the integrated circuit during the 1960s, radically changed the process,11 its impact on the media was not immediately 12 . As time went by, computers became smaller and mo re powerful, and they became “personal” too, as well as 13 , with display becoming sharper and storage 14 increasing. They were thought of, like people, 15 generations, with the distance between generations much 16 .It was within the com puter age that the term “information society” began to be widely used to describe the 17 within which we now live. The communications revolution has 18 both work and leisure and how we think and feel both about place and time, but there have been 19 view about its economic, political, social and cultural implications. “Benefits” have been weighed 20 “harmful” outcomes. And generalizations have proved difficult.1. ［A］between ［B］before ［C］since ［D］later2. ［A］after ［B］by ［C］during ［D］until3. ［A］means ［B］method ［C］medium ［D］measure4. ［A］process ［B］company ［C］light ［D］form5. ［A］gathered ［B］speeded ［C］worked ［D］picked6. ［A］on ［B］out ［C］over ［D］off7. ［A］of ［B］for ［C］beyond ［D］into8. ［A］concept ［B］dimension ［C］effect ［D］perspective9. ［A］indeed ［B］hence ［C］however ［D］therefore10. ［A］brought ［B］followed ［C］stimulated ［D］characterized11. ［A］unless ［B］since ［C］lest ［D］although12. ［A］apparent ［B］desirable ［C］negative ［D］plausible13. ［A］institutional ［B］universal ［C］fundamental ［D］instrumental14. ［A］ability ［B］capability ［C］capacity ［D］faculty15. ［A］by means of ［B］in terms of ［C］with regard to［D］in line with16. ［A］deeper ［B］fewer ［C］nearer ［D］smaller17. ［A］context ［B］range ［C］scope ［D］territory18. ［A］regarded ［B］impressed ［C］influenced ［D］effected19. ［A］competitive ［B］controversial ［C］distracting ［D］irrational20. ［A］above ［B］upon ［C］against ［D］withSection II Reading ComprehensionPart ADirections:Read the following four texts. Answer the questions below each text by choosing [A], [B], [C] or [D]. Mark your answers on ANSWER SHEET 1. (40 points)Text 1If you intend using humor in your talk to make people smile, you must know how to identify shared experiences and problems. Your humor must be relevant to the audience and should help to show them that you are one of them or that you understand their situation and are in sympathy with their point of view. Depending on whom you are addressing, the problems will be different. If you are talking to a group of managers, you may refer to the disorganized methods of their secretaries; alternatively if you are addressing secretaries, you may want to comment on their disorganized bosses.Here is an example, which I heard at a nurses’ convention, of a story which works well because the audience all shared the same view of doctors. A man arrives in heaven and is being shown around by St. Peter. He sees wonderful accommodations, beautiful gardens, sunny weather, and so on. Everyone is very peaceful, polite and friendly until, waiting in a line for lunch, the new arrival is suddenly pushed aside by a man in a white coat, who rushes to the head of the line, grabs his food and stomps over to a table by himself. “Who is that?” the new arrival asked St. Peter. “Oh, that’s God,” came the reply, “but sometimes he thinks he’s a doctor.”If you are part of the group which you are addressing, you will be in a position to know the experiences and problems which are common to all of you and it’ll be appropriate for you to make a passing remark about the inedible canteen food or the chairman’s notorious bad taste in ties. With other audiences you mustn’t att empt to cut in with humor as they will resent an outsider making disparaging remarks about their canteen or their chairman. You will be on safer ground if you stick to scapegoats like the Post Office or the telephone system.If you feel awkward being humorous, you must practice so that it becomes more natural. Include a few casual and apparently off-the-cuff remarks which you can deliver in a relaxed and unforced manner. Often it’s the delivery which causes the audience to smile, so speak slowly and remember that a raised eyebrow or an unbelieving look may help to show that you are making a light-hearted remark.Look for the humor. It often comes from the unexpected. A twist on a familiar quote “If at first you don’t succeed, give up” or a play on words o r on a situation. Search for exaggeration and understatement. Look at your talk and pick out a few words or sentences which you can turn about and inject with humor.21. To make your humor work, you should .[A] take advantage of different kinds of audience[B] make fun of the disorganized people[C] address different problems to different people[D] show sympathy for your listeners22. The joke about doctors implies that, in the eyes of nurses, they are .[A] impolite to new arrivals[B] very conscious of their godlike role[C] entitled to some privileges[D] very busy even during lunch hours23. It can be inferred from the text that public services .[A] have benefited many people[B] are the focus of public attention[C] are an inappropriate subject for humor[D] have often been the laughing stock24. To achieve the desired result, humorous stories should be delivered .[A] in well-worded language[B] as awkwardly as possible[C] in exaggerated statements[D] as casually as possible25. The best title for the text may be .[A] Use Humor Effectively[B] Various Kinds of Humor[C] Add Humor to Speech[D] Different Humor StrategiesText 2Since the dawn of human ingenuity, people have devised ever more cunning tools to cope with work that is dangerous, boring, burdensome, or just plain nasty. That compulsion has resulted in robotics—the science of conferring various human capabilities on machines. And if scientists have yet to create the mechanical version of science fiction, they have begun to come close.As a result, the modern world is increasingly populated by intelligent gizmos whose presence we barely notice but whose universal existence has removed much human labor. Our factories hum to the rhythm of robot assembly arms. Our banking is done at automated teller terminals that thank us with mechanical politeness for the transaction. Our subway trains are controlled by tireless robot-drivers. And thanks to the continual miniaturization of electronics and micro-mechanics, there are already robot systems that can perform some kinds of brain and bone surgery with submillimeter accuracy—far greater precision than highly skilled physicians can achieve with their hands alone.But if robots are to reach the next stage of laborsaving utility, they will have to operate with less human supervision and be able to make at least a few decisions for themselves—goals that pose a real challenge. “While we know how to tell a robot to handle a specific error," says Dave Lavery, manager of a robotics p rogram at NASA, “we can't yet give a robot enough ‘common sense’ toreliably interact with a dynamic world.”Indeed the quest for true artificial intelligence has produced very mixed results. Despite a spell of initial optimism in the 1960s and 1970s when it appeared that transistor circuits and microprocessors might be able to copy the action of the human brain by the year 2010, researchers lately have begun to extend that forecast by decades if not centuries.What they found, in attempting to model thought, is that the human brain's roughly one hundred billion nerve cells are much more talented—and human perception far more complicated—than previously imagined. They have built robots that can recognize the error of a machine panel by a fraction of a millimeter in a controlled factory environment. But the human mind can glimpse a rapidly changing scene and immediately disregard the 98 percent that is irrelevant, instantaneously focusing on the monkey at the side of a winding forest road or the single suspicious face in a big crowd. The most advanced computer systems on Earth can't approach that kind of ability, and neuroscientists still don’t know quite how we do it.26. Human ingenuity was initially demonstrated in .[A] the use of machines to produce science fiction.[B] the wide use of machines in manufacturing industry.[C] the invention of tools for difficult and dangerous work.*D+ the elite’s cunning tackling of dangerous and boring work.27. The word “gizmos”(line 1, paragraph 2) most probably means .[A] programs ［B］experts ［C］devices ［D］creatures28. According to the text, what is beyond man's ability now is to design a robot that can .[A] fulfill delicate tasks like performing brain surgery.[B] interact with human beings verbally.[C] have a little common sense.[D] respond independently to a changing world.29. Besides reducing human labor, robots can also .[A] make a few decisions for themselves.[B] deal with some errors with human intervention.[C] improve factory environments.[D] cultivate human creativity.30. The author uses the example of a monkey to argue that robots are .[A] expected to copy human brain in internal structure.[B] able to perceive abnormalities immediately.[C] far less able than human brain in focusing on relevant information.[D] best used in a controlled environment.Text 3Could the bad old days of economic decline be about to return? Since OPEC agreed to supply-cuts in March, the price of crude oil has jumped to almost $26 a barrel, up from less than $10 last December. This near-tripling of oil prices calls up scary memories of the 1973 oil shock, when prices quadrupled, and 1979-1980, when they also almost tripled. Both previous shocks resulted in double-digit inflation and global economic decline. So where are the headlineswarning of gloom and doom this time?The oil price was given another push up this week when Iraq suspended oil exports. Strengthening economic growth, at the same time as winter grips the northern hemisphere, could push the price higher still in the short term.Yet there are good reasons to expect the economic consequences now to be less severe than in the 1970s. In most countries the cost of crude oil now accounts for a smaller share of the price of petrol than it did in the 1970s. In Europe, taxes account for up to four-fifths of the retail price, so even quite big changes in the price of crude have a more muted effect on pump prices than in the past.Rich economies are also less dependent on oil than they were, and so less sensitive to swings in the oil price. Energy conservation, a shift to other fuels and a decline in the importance of heavy, energy-intensive industries have reduced oil consumption. Software, consultancy and mobile telephones use far less oil than steel or car production. For each dollar of GDP (in constant prices) rich economies now use nearly 50% less oil than in 1973. The OECD estimates in its latest Economic Outlook that, if oil prices averaged $22 a barrel for a full year, compared with $13 in 1998, this would increase the oil import bill in rich economies by only 0.25-0.5% of GDP. That is less than one-quarter of the income loss in 1974 or 1980. On the other hand, oil-importing emerging economies—to which heavy industry has shifted—have become more energy-intensive, and so could be more seriously squeezed.One more reason not to lose sleep over the rise in oil prices is that, unlike the rises in the 1970s, it has not occurred against the background of general commodity-price inflation and global excess demand. A sizable portion of the world is only just emerging from economic decline. The Economist’s commodity price index is broadly unchanging from a year ago. In 1973 commodity prices jumped by 70%, and in 1979 by almost 30%.31. The main reason for the latest rise of oil price is_______[A] global inflation. [B] reduction in supply.[C]fast growth in economy. [D] Iraq’s suspension of exports.32. It can be inferred from the text that the retail price of petrol will go up dramatically if______.[A] price of crude rises. [B] commodity prices rise.[C] consumption rises. [D] oil taxes rise.33. The estimates in Economic Outlook show that in rich countries_______.［A］heavy industry becomes more energy-intensive.［B］income loss mainly results from fluctuating crude oil prices.［C］manufacturing industry has been seriously squeezed.［D］oil price changes have no significant impact on GDP.34. We can draw a conclusion from the text that_______.［A］oil-price shocks are less shocking now.［B］inflation seems irrelevant to oil-price shocks.［C］energy conservation can keep down the oil prices.［D］the price rise of crude leads to the shrinking of heavy industry.35. From the text we can see that the writer seems__________.［A］optimistic. ［B］sensitive. ［C］gloomy. ［D］scared.Text 4The Supreme Court’s decisions on physician-assisted suicide carry important implications for how medicine seeks to relieve dying patients of pain and suffering.Although it ruled that there is no constitutional right to physician-assisted suicide, the Court in effect supported the medical principle of “double effect”, a centur ies-old moral principle holding that an action having two effects—a good one that is intended and a harmful one that is foreseen—is permissible if the actor intends only the good effect.Doctors have used that principle in recent years to justify using high doses of morphine to control terminally ill patients’pain, even though increasing dosages will eventually kill the patient. Nancy Dubler, director of Montefiore Medical Center, contends that the principle will shield doctors who “until now have very, v ery strongly insisted that they could not give patients sufficient medication to control their pain if that might hasten death”.George Annas, chair of the health law department at Boston University, maintains that, as long as a doctor prescribes a drug for a legitimate medical purpose, the doctor has done nothing illegal even if the patient uses the drug to hasten death. “It’s like surgery,” he says. “We don’t call those deaths homicides because the doctors didn’t intend to kill their patients, although t hey risked their death. If you’re a physician, you can risk your patient’s suicide as long as you don’t intend their suicide.”On another level, many in the medical community acknowledge that the assisted-suicide debate has been fueled in part by the despair of patients for whom modern medicine has prolonged the physical agony of dying.Just three weeks before the Court’s ruling on physician-assisted suicide, the National Academy of Science (NAS) released a two-volume report, Approaching Death: Improving Care at the End of Life. It identifies the undertreatment of pain and the aggressive use of “ineffectual and forced medical procedures that may prolong and even dishonor the period of dying” as the twin problems of end-of-life care.The profession is taking steps to require young doctors to train in hospices, to test knowledge of aggressive pain management therapies, to develop a Medicare billing code for hospital-based care, and to develop new standards for assessing and treating pain at the end of life.Annas says lawyers can play a key role in insisting that these well-meaning medical initiatives translate into better care. “Large numbers of physicians seem unconcerned with the pain their patients are needlessly and predictably suffering”, to the extent that it constitutes “systematic patient abuse”. He says medical licensing boards “must make it clear...that painful deaths are presumptively ones that are incompetently managed and should result in license suspension”.36. From the first three paragraphs, we learn that .*A+ doctors used to increase drug dosages to control their patients’pain[B] it is still illegal for doctors to help the dying end their lives[C] the Supreme Court strongly opposes physician-assisted suicide[D] patients have no constitutional right to commit suicide37. Which of the following statements its true according to the text?*A+ Doctors will be held guilty if they risk their patients’death.[B] Modern medicine has assisted terminally ill patients in painless recovery.[C] The Court ruled that high-dosage pain-relieving medication can be prescribed.*D+ A doctor’s medication is no longer justified by his intentions.38. According to the NAS’s report, one of the problems in end-of-life care is .[A] prolonged medical procedures [B] inadequate treatment of pain[C] systematic drug abuse [D] insufficient hospital care39. Which of the following best defines the word “aggressive” (line 4, paragraph 7)?[A] Bold. [B] Harmful. [C] Careless. [D] Desperate40. George Annas would probably agree that doctors should be punished if they .[A] manage their patients incompetently[B] give patients more medicine than needed[C] reduce drug dosages for their patients[D] prolong the needless suffering of the patientsPart BDirections:Read the following text carefully and then translate the underlined segments into Chinese. Your translation should be written clearly on ANSWER SHEET 2. (10 points)Almost all our major problems involve human behavior, and they cannot be solved by physical and biological technology alone. What is needed is a technology of behavior, but we have been slow to develop the science from which such a technology might be drawn.（41）One difficulty is that almost all of what is called behavioral science continues to trace behavior to states of mind, feelings, traits of character, human nature, and so on. Physics and biology once followed similar practices and advanced only when they discarded them. （42）The behavioral sciences have been slow to change partly because the explanatory items often seem to be directly observed and partly because other kinds of explanations have been hard to find. The environment is obviously important, but its role has remained obscure. It does not push or pull, it selects, and this function is difficult to discover and analyze.（43）The role of natural selection in evolution was formulated only a little more than a hundred years ago, and the selective role of the environment in shaping and maintaining the behavior of the individual is only beginning to be recognized and studied. As the interaction between organism and environment has come to be understood, however, effects once assigned to states of mind, feelings, and traits are beginning to be traced to accessible conditions, and a technology of behavior may therefore become available. It will not solve our problems, however, until it replaces traditional prescientific views, and these are strongly entrenched. Freedom and dignity illustrate the difficulty. （44）They are the possessions of the autonomous（self-governing）man of traditional theory, and they are essential to practices in which a person is held responsible for his conduct and given credit for his achievements. A scientific analysis shifts both the responsibility and the achievement to the environment. It also raises questions concerning “values”. Who will use a technology and to what ends? （45）Until these issues are resolved, a technology of behavior will continue to be rejected, and with it possibly the only way to solve our problems.Section III Writing46. Directions:Study the following picture carefully and write an essay entitled “Cultures National and International”.In the essay you should1. describe the picture and interpret its meaning, and2. give your comment on the phenomenon.You should write about 200 words neatly on ANSWER SHEET 2. (20 points)An American girl in traditional Chinese costume（服装）第一部分英语知识应用试题解析一、文章总体分析本文主要介绍了计算机的发展对通信革命及人们的生存方式产生的影响。
2002年考研数学(三)真题及详细解析
2002 年全国硕士研究生入学统一考试数学三试题及解析一、填空题(本题共5小题,每小题3分,满分15分.把答案填在题中横线上) ⑴ 设常数12a ≠，则21lim ln[]________(12)n n n na n a →∞-+=-. 【分析】将所求极限转换为1ln[1](12)lim1n n a n→∞+-，利用等价无穷小代换化简求解，或利用重要极限。
【详解】法一：11ln[1]211(12)(12)lim ln[]limlim 11(12)12nn n n n na n a n a n a an n→∞→∞→∞+-+--===-- 法二：11(12)12122111lim ln[]lim ln[1]lim ln (12)(12)12n a n aa n n n n na e n a n a a-⨯--→∞→∞→∞-+=+==---⑵ 交换积分次序：111422104(,)(,)________yyydy f x y dx dy f x y dx +=⎰⎰⎰⎰.【分析】写出对应的二重积分积分域D 的不等式，画出D 的草图后，便可写出先对y 后对x 的二次积分【详解】对应的积分区域12D D D =+，其中11(,)0,4D x y y y x y ⎧⎫=≤≤≤≤⎨⎬⎩⎭2111(,),422D x y y y x ⎧⎫=≤≤≤≤⎨⎬⎩⎭画出D 的草图如右图所示，则D 也可表示为 21(,)0,2D x y x x y x ⎧⎫=≤≤≤≤⎨⎬⎩⎭故211114222104(,)(,)(,)yxyyxdy f x y dx dy f x y dx dx f x y dy +=⎰⎰⎰⎰⎰⎰⑶ 设三阶矩阵122212304A -⎡⎤⎢⎥=⎢⎥⎢⎥⎣⎦，三维列向量(,1,1)Ta α=。
已知A α与α线性相关，则______a =。
【分析】由A α与α线性相关知，存在常数k 使得A k αα=，及对应坐标成比例，由此求出a【详解】由于122212123304134a a A a a α-⎡⎤⎡⎤⎡⎤⎢⎥⎢⎥⎢⎥==+⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥+⎣⎦⎣⎦⎣⎦由A α与α线性相关可得：233411a a a a ++==，从而1a =-。
机械原理考研真题
机械原理考研真题以下为机械原理考研真题：问题1：某机械系统是由一台电动机和一台液压缸组成的，电动机驱动液压泵工作，液压泵通过油管将液压油输送到液压缸中，从而驱动执行机构进行工作。
试分析该机械系统的工作原理并说明各个元件的功能。
问题2：针对一台喷气发动机的涡轮叶片设计问题，假设叶片尺寸已确定，求该叶片的最佳攻角，并给出最佳攻角的物理意义及其对发动机性能的影响。
问题3：在某个机械系统中，传动带传递来自电动机的动力，但由于传动带松紧不均匀，使得传动过程中产生了明显的动态振动和噪声。
请设计一种可行的动力传递方式，以解决该问题，并分析该动力传递方式与传统传动方式的优劣势。
问题4：某个电梯系统中，电梯的刹车装置失灵，导致电梯无法在特定楼层停车。
请设计一种新的电梯刹车装置，确保电梯能够可靠地在指定楼层停车，并分析该刹车装置的工作原理和安全性能。
问题5：液压缸是工程中常用的执行元件之一，它根据液压力来产生线性运动。
请分析液压缸的主要结构和工作原理，并说明液压缸在工程应用中的优势和限制。
问题6：某车辆的制动系统由刹车片和刹车盘组成，刹车片将力传递给刹车盘以实现车辆的制动。
请分析刹车系统的工作原理，并探讨刹车片与刹车盘之间的磨损和热效应对刹车性能的影响。
问题7：对于某机械设计问题，需要进行强度和刚度的计算以保证设计的可靠性。
请分析强度和刚度的概念，并说明强度和刚度计算在机械设计中的作用和意义。
问题8：在机械系统中，常常会出现摩擦现象，摩擦对系统的性能和寿命都有一定影响。
请分析摩擦的类型及其对机械系统的影响，并提出减小摩擦的设计措施。
问题9：在某个机械系统中，运动副的配合间隙严重影响了系统的精度和稳定性。
请解释配合间隙的概念和影响，并分析减小配合间隙的方法及其适用范围。
问题10：某机械装置需要进行离心力的计算，以保证设备在高速旋转时的安全性。
请分析离心力的产生原理，并给出离心力计算公式及其在机械设计中的应用。
机械原理考研题库及答案详解大全
机械原理考研题库及答案详解大全机械原理考研题库及答案详解大全机械原理是机械工程专业考研的重要科目之一，涉及到力学、材料力学、结构力学等多个方面的知识。
为了帮助考生更好地备考，本文将为大家提供一份机械原理考研题库及答案详解大全。
第一部分：力学基础1. 以下哪个不是刚体力学的基本假设？A. 刚体是一个质点系B. 刚体的形状和大小不变C. 刚体的内部无任何相对运动D. 刚体上任意两点之间的距离不变答案：A解析：刚体力学的基本假设包括刚体的形状和大小不变、刚体的内部无任何相对运动、刚体上任意两点之间的距离不变。
刚体是一个质点系并不是刚体力学的基本假设。
2. 以下哪个不是刚体力学的基本定律？A. 牛顿第一定律B. 牛顿第二定律C. 牛顿第三定律D. 动量守恒定律答案：D解析：刚体力学的基本定律包括牛顿第一定律、牛顿第二定律和牛顿第三定律。
动量守恒定律是力学的基本定律，但不属于刚体力学的基本定律。
3. 以下哪个不是刚体力学的基本方程？A. 动力学方程B. 运动学方程C. 平衡方程D. 动量守恒方程答案：D解析：刚体力学的基本方程包括动力学方程、运动学方程和平衡方程。
动量守恒方程是力学的基本方程，但不属于刚体力学的基本方程。
第二部分：材料力学1. 以下哪个不是材料力学的基本假设？A. 弹性体的应力与应变之间存在线性关系B. 弹性体的体积不变C. 材料的应力与应变之间存在线性关系D. 材料的应力与应变之间存在非线性关系答案：D解析：材料力学的基本假设包括弹性体的应力与应变之间存在线性关系、弹性体的体积不变、材料的应力与应变之间存在线性关系。
材料的应力与应变之间存在非线性关系并不是材料力学的基本假设。
2. 以下哪个不是材料力学的基本定律？A. 霍克定律B. 应力应变关系C. 应力平衡定律D. 应变平衡定律答案：D解析：材料力学的基本定律包括霍克定律、应力应变关系和应力平衡定律。
应变平衡定律是材料力学的基本定律，但不属于刚体力学的基本定律。
机械硕士考研试题及答案
机械硕士考研试题及答案一、选择题（每题2分，共10分）1. 机械设计中，齿轮传动的主要失效形式是（）。
A. 磨损B. 疲劳C. 腐蚀D. 变形答案：B2. 在材料力学中，下列哪项不是材料的力学性能指标？A. 弹性模量B. 屈服强度C. 硬度D. 密度答案：D3. 根据机械原理，四杆机构中，若最短杆长度等于最长杆长度的一半，则机构为（）。
A. 双曲柄机构B. 双摇杆机构C. 曲柄摇杆机构D. 摇杆曲柄机构答案：A4. 在液压系统中，下列哪个元件不是用来控制液体流动方向的？A. 单向阀B. 溢流阀C. 换向阀D. 节流阀答案：D5. 机械制造中，数控加工精度的提高主要依赖于（）。
A. 刀具材料B. 加工工艺C. 控制系统D. 机床刚度答案：C二、填空题（每题2分，共10分）1. 在机械设计中，为了提高齿轮的使用寿命，通常采用_________进行热处理。
答案：渗碳2. 材料的疲劳强度与其_________有关。
答案：循环次数3. 四杆机构中，若最短杆长度大于最长杆长度的一半，则机构为_________。
答案：双摇杆机构4. 液压系统中，_________的作用是防止系统压力超过设定值。
答案：溢流阀5. 数控加工中，刀具的_________直接影响加工精度。
答案：磨损三、简答题（每题5分，共20分）1. 简述机械设计中，轴承的选型原则。
答案：轴承的选型应考虑轴承的承载能力、转速、工作温度、安装空间、经济性等因素。
2. 说明材料力学中，材料的弹性模量与屈服强度的区别。
答案：弹性模量是材料在弹性阶段内应力与应变比值的物理量，而屈服强度是材料开始产生塑性变形时的应力值。
3. 描述四杆机构中，曲柄摇杆机构的工作原理。
答案：曲柄摇杆机构中，曲柄通过连杆驱动摇杆，实现往复运动与旋转运动的转换。
4. 解释液压系统中，单向阀的作用。
答案：单向阀的作用是允许液体单向流动，防止液体反向流动，确保系统安全。
四、计算题（每题10分，共20分）1. 已知一齿轮传动系统，主动齿轮的转速为1000转/分钟，传动比为3:1，求从动齿轮的转速。