一种全柔顺六稳态机构的设计  

Design Approach for a Fully Compliant Sexastable Mechanism

作　　者：勾燕洁[1] 张守银 陈贵敏[1] 

机构地区：[1]西安电子科技大学机电工程学院,西安710071 [2]北方通用电子集团有限公司,西安710100

出　　处：《机械工程学报》2015年第7期61-66,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51175396);中央高校基本科研业务费专项(K5051204021;K5051304023);新世纪优秀人才支持计划(NCET-11-0689)资助项目

摘　　要：多稳态机构因不需输入能量就可保持多个稳定平衡状态而在生产生活中得到越来越广泛的应用。全柔顺多稳态机构免装配、无摩擦、低能耗,但因为柔顺片段大变形时容易产生应力集中、输出非线性等原因,全柔顺多稳态机构的设计难度较大。提出一种全柔顺六稳态机构的设计方法,由两个临界跳转力不同的双稳态机构和一个柔顺片段组成机构,成功实现六个稳定平衡状态。对柔顺片段用伪刚体模型法建模,并通过比较两部分结构的力-位移特性给出机构具有六个稳定平衡状态的条件,从而避免了非线性分析;考虑机构的实际运动给出柔顺片段的刚度范围计算公式,设计者可据此选择合适的刚度完成全柔顺六稳态机构的设计。用ANSYS得到的输出力特性和样机测试证实了该设计方法的正确。Multistable mechanisms can stay at multiple stable equilibrium positions without power input, and get more and more widely use in many regions. Fully compliant multistable mechanisms have some advantages such as free of assembly, frictionless, lower power consumption, and so on, but they are difficult to design because of the stress concentration and nonlinear characteristics caused by the large deformation of the flexible segments. A design approach is presented for a type of fully compliant sexastable mechanism, which possesses six stable equilibrium positions, employing a compliant structure and two compliant bistable mechanisms with different snap-through forces. The model of the compliant structure is built by pseudo-rigid-body model to achieve the force-deflection characteristics. The force-deflection curves of the two components are compared to obtain the stability criterion for the sexastable mechanism, avoiding nonlinear analysis. Formulas are proposed to determine the stiffness arrange of the flexible segments of the compliant structure, which is the basis of the size parameters design for the flexible segments. A design example is given and the finite element analysis by ANSYS software and the prototype test prove the feasibility of this design approach.

关 键 词：多稳态机构 伪刚体模型 全柔顺机构 

分 类 号：TH122[机械工程—机械设计及理论]