Multi-patch Isogeometric Analysis of Planar Compliant Mechanisms

Multi-patch isogeometric analysis (IGA) of planar compliant mechanism, based on the planar Timoshenko beam theory, is presented. IGA is a new computational framework that seamlessly integrates geometric modelling and deformation analysis. The multi-patch technique enables analysis of multi-segmented beam structures with bifurcation points and star junctions. Methods to handle various Dirichlet and Neumann boundary conditions in the framework of IGA are also discussed. Displacement and section force distributions obtained from IGA are compared with the results obtained from finite element analysis (FEA) and analytical solutions. IGA is particularly advantageous in the problems involving geometries with large curvatures, such as curved beams, curved thin plates, etc. Such curved geometries can be used to model various interconnected members in a compliant mechanism. The multi-patch IGA approach discussed in this paper can be used to improve the efficiency of shape optimization process of planar compliant mechanisms, by providing better control over the shape using fewer design variables and by reducing errors arising due to geometric approximation.