Stiffness Analysis of a Compliant Mechanism Considering Complex Deformations of All Flexible Structure Units

Title:Stiffness Analysis of a Compliant Mechanism Considering Complex Deformations of All Flexible Structure Units

Volume: 6 Issue: 3

Author(s): Jinliang Gong, Jinxiang Pang and Yanfei Zhang

Affiliation:

Keywords: ANSYS, compliant mechanism, flexible unit, micro displacement amplification module, pseudo-rigid-body model, stiffness.

Abstract: Considering the disadvantages such as that pseudo-rigid-body method has low precision and it is difficult to build the real deformation-compatibility equations only by using flexibility matrix method, a stiffness analysis method of planar compliant mechanism is put forward. The method takes into account of complex deformations of all flexible structure units. By treating every structure units other than the base as flexible, the whole structure stiffness can be obtained based on force equilibrium equations. It considers deformations of all the flexible units in each direction synthetically, which makes the result close to its actual situation to a great extent. At the same time, it will reduce lots of computational work by avoiding deformation-compatibility problem between flexible and rigid units, which must be dealt with separately for the other methods. Stiffness of a microdisplacement amplification module is analyzed by different methods. Analytical data shows that the pseudo-rigid-body model method will introduce comparatively large error, especially for these compliant mechanisms with longer lever. It can be used only in situations of lower precision requirements. Results of the complete flexible unit method are much closer to that of ANSYS. It is proved that the mechanism stiffness K relates to the ratio of power arm and resisting arm and gains minimum when the two arms are equal. And the inflection point of stiffness-resisting arm history occurs just in this situation. These results are of great importance for the parameter design of lever-amplifier mechanism with given stiffness.

Cite this article as:

Gong Jinliang, Pang Jinxiang and Zhang Yanfei, Stiffness Analysis of a Compliant Mechanism Considering Complex Deformations of All Flexible Structure Units, Micro and Nanosystems 2014; 6 (3) . https://dx.doi.org/10.2174/187640290603150112122727