Dynamic analysis of the precision compliant mechanisms considering thermal effect

Deformations and stresses are produced not by mechanical forces alone, but by temperature variation as well. The thermal stress caused by heat is likely to be the decisive factor. Thus it is necessary to consider the thermal effect at a certain temperature range for analysis and design of a precision compliant mechanism. Firstly, the generalized equations of motion of the compliant mechanism considering the thermal effects are developed based on the finite element method. Secondly, the right-circular flexure hinge is treated as a three nodes element, in which there are three degrees of freedom at each node. The closed-form solutions of the element stiffness and mass matrices for the flexure hinge are obtained. Finally, analytical and experimental studies are carried out to an ultra-precision positioning stage. The analytical results have a good match with that of the experimental results, which indicate that the analytical method developed in this study is valid. The thermal effect has a strong impact on the performances of the precision positioning stage, and it is essential to consider the thermal effect when analysis and design a compliant mechanism system.