摘要
分布式全柔顺机构不包含刚性杆件和运动副,其运动与能量的转换完全由柔顺构件的变形来实现,具有结构简单、质量轻和无关节间隙等优点。以J型储能脚为例研究此类机构伪刚体建模方法。为了提高模型精度,将柔顺机构等效成弹性铰接多刚体系统,基于柔顺构件的几何形状和刚度分布提出伪刚性段划分的曲率原则与刚度原则,给出等效关节扭簧常数的修正计算公式。应用影响系数理论给出弹性铰接多刚体系统受力变形的计算公式。通过与有限元计算结果对比,讨论伪刚体模型分段方法、段数和扭簧常数等因素对模型精度的影响,验证基于几何形状和刚度分布的伪刚性段划分方法的合理性,并获得了J型储能脚合理的划分段数和修正系数值。本建模方法不仅适用于开环分布式柔顺机构,还可以进一步应用于闭环分布式柔顺机构的伪刚体建模。
As the distributed fully-compliant mechanism contains no rigid components and kinematic-pairs,the conversion between its motion and energy is realized by the deformation of compliant components,so it has the advantages of simple construction,less mass and no joint clearance.The pseudo-rigid-body modeling method for this kind of mechanism is investigated by taking J-type energy storing foot as an example.To enhance the model precision,the compliant mechanism is equalized to the elastically articulated multi-rigid-body system,the curvature principle and stiffness principle for pseudo-rigid-segments partition are proposed on the basis of geometrical shape and stiffness distribution of compliant components,and the modified formula for calculating torsional spring constants of equivalent joints is developed.The formula for calculating deformations of a multi-rigid-body system is also given on the basis of influence coefficient theory.By comparing with the corresponding results from finite element analysis,the influence of partition methods,partition number and torsional spring constants on the model precision is investigated.The results show that the partition method based on geometrical shape and stiffness distribution is effective.The appropriate segment number of the J-type energy-storing foot and the correction coefficients of torsional spring constants are obtained.The presented modeling method can be further applied to the design and analysis of the distributed fully-compliant mechanisms with closed loops.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2010年第19期17-23,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金(50675191)
教育部博士学科点专项科研基金(20060216008)资助项目
关键词
分布式全柔顺机构
伪刚体建模
伪刚性段划分
储能脚
Distributed fully-compliant mechanism Pseudo-rigid-body modeling Pseudo-rigid-segment partition Energy-storing foot
