柔性机械臂用超弹性材料制备及性能研究

Abstract

Robotics has developed rapidly in recent decades and has been applied in production and life. As an important execution end of a robot, a robotic arm can perform tasks such as catching, lifting, and assembly. Currently rigid mechanical arms are mostly widely used in industrial production, which consist of several motion pairs of the alloy structure, and control their motion mainly through the control of motion pairs. However, when the movement is complicated, the rigid structure will be complicated and the quality and volume will increase, resulting in poor flexibility. Flexible manipulators that mimic molluscs have small volume, simple structure, simple driving, and flexible movement. They can operate in a narrow environment and make up for the insufficiency of rigid robotic arms in space-limited, precise operation, and fragile items.

In this paper, from the material point of view, we design the flexible mechanical arm composite structure by the use of the super-elastic silicone rubber materials and the difference in the elastic modulus, the elongation of different silicone rubber materials. A high strength PDMS silicone rubber is used in the center to support the entire structure, and Ecoflex series silicone rubber with good elasticity is used at the outer layer to achieve the use of capture with bending at low pressure. The ABAQUS finite element simulation method was used to optimize the shape of the Pneumatic channel The finite element simulation was performed on the bending behavior of the arc-shape, the circular l, and the arc-shape with changing section air channel after Pneumatic driving. The gas pressure-curvature curve of the structure shows that the curved air channel can achieve a greater curvature at a lower pressure.

The curing process of two types of silicone rubber used for flexible manipulators was studied. The effects of curing time, curing temperature and the ratio of two components of A and B on the structure and properties of silicone rubber were studied. The effects of solidification temperature changing from 40°C to 120°C, curing time changing from 0.5 to 24h, ratio of A and B components changing from 0.8 to 1.2 on mechanical properties of Ecoflex series silicone rubber and PDMS silicone rubber were studied. The changes in glass transition temperature, chemical groups and surface

elements was studied by DMA, IR and XPS., revealing the effect of the curing process on mechanical properties and internal structures. The optimum curing process is 60°C for 4h for Ecoflex 00-30, 60°C for 3h for Ecoflex 00-50, 60°C for 20h for PDMS. In addition, in order to ensure the stability of the flexible manipulator in the working process, the mechanical properties of the two type of silicone rubbers after aging were measured. And the glass transition temperature, chemical groups, and surface components of the two silicone rubbers before and after aging were analyzed by DMA, IR and XPS. Changes, analysis of aging mechanism. Ecoflex silicone rubber ages due to main chain Si-O-Si breakage. PDMS silicone rubber causes of aging is branch chain’s fracture. The flexible mechanical arm is a composite structure of two materials. The combination of the two materials under different curing processes was studied. It was found that the Ecoflex 00-30-PDMS-Ecoflex 00-30 composite structure was cured at 60° C. for 0.5 h, 6 h and 4h respectively., the performance mechanics is better.

Based on this research, different curing process combinations were selected to mold the flexible manipulator using the mold casting method. The aerodynamic experiment was performed on the pneumatic platform of the prepared flexible manipulator. The effects of different curing processes, different inflation modes, and different outer layer materials on the kinematic behavior and cycle performance of the flexible manipulator were studied, and the capture behavior was comprehensively studied. It has been found that the Ecoflex 00-50 requires more pressure than the Ecoflex 00-30, but its cycle performance is lower than that of the Ecoflex 00-30. Its cycle performance is better than the fast air charge at slow inflation.

Keywords: Silicone rubber, Flexible mechanical arm, Aerodynamic performance.

摘要 ............................................................................................................................... I Abstract........................................................................................................................... III

第1章绪论 (1)

研究背景及意义 (1)

机械臂研究现状 (1)

1.2.1 刚性机械臂 (2)

1.2.2 柔性机械臂 (3)

1.2.3 柔性机械臂用硅橡胶 (12)

橡胶有限元模拟 (13)

主要研究内容 (15)

第2章实验材料及方法 (17)

原材料 (17)

Ecoflex00-30及PDMS固化工艺试验方案 (18)

2.2.1 Ecoflex 00-30固化工艺参数及方案 (18)

2.2.2 Ecoflex 00-50固化工艺参数及方案 (19)

2.2.3 PDMS固化工艺参数及方案 (19)

2.2.4 Ecoflex 00-30-PDMS复合结构的制备 (20)

柔性机械臂制备 (21)

材料的表征与测试 (22)

2.4.1 力学性能测试 (22)

2.4.2 动态热机械（DMA）分析 (22)

2.4.3 差示扫描量热法 (23)

2.4.4 组织结构表征 (23)

2.4.5 气动性能测试 (23)

第3章柔性机械臂结构设计 (26)

引言 (26)

柔性机械臂结构设计及有限元模拟 (26)

3.2.1 各向同性超弹性材料本构模型 (26)

3.2.2 柔性机械臂结构设计 (27)

3.2.3 柔性机械臂结构有限元模拟 (29)

外加纤维层柔性机械臂设计及有限元模拟 (32)

3.3.1 各向异性超弹性材料本构模型 (32)

3.3.2 材料不稳定性分析方法—Riks方法 (34)

3.3.3 外加纤维层柔性机械臂结构设计 (34)

本章小结 (38)

第4章硅橡胶材料固化工艺对性能及结构影响 (39)

引言 (39)

固化工艺Ecoflex 00-30对性能及结构影响 (39)

4.2.1 双组分配比对Ecoflex 00-30力学性能影响 (39)

4.2.2 固化温度对Ecoflex 00-30性能及结构影响 (40)

4.2.3 固化时间对Ecoflex 00-30性能及结构影响 (47)

4.2.4 Ecoflex 00-30老化性能 (51)

固化工艺对Ecoflex 00-50性能及结构影响 (54)

4.3.1 固化温度对Ecoflex 00-50性能及结构影响 (54)

4.3.2 固化时间对Ecoflex 00-50性能及结构影响 (57)

4.3.3 Ecoflex 00-50老化性能 (59)

固化工艺对PDMS性能及结构影响 (62)

4.4.1 固化温度对PDMS性能及结构影响 (62)

4.4.2 固化时间对PDMS性能及结构影响 (66)

4.4.3 PDMS老化性能 (69)

Ecoflex 00-30-PDMS层状复合结构力学行为 (72)

4.5.1 Ecoflex 00-30-PDMS层状复合结构力学性能 (72)

4.5.2 复合结构断裂特性 (73)

本章小结 (75)

第5章柔性机械臂气动行为 (76)

引言 (76)

机械臂单次气动行为 (76)

柔性机械臂循环气动行为 (78)

5.3.1 柔性机械臂循环过程中运动行为 (78)

5.3.2 柔性机械臂的循环失效 (84)

本章小结 (84)

结论 (86)

参考文献 (87)

哈尔滨工业大学学位论文原创性声明和使用权限 (91)

致谢 (92)