Finite element analysis on the static stiffness of a 3prs/ups redundant parallel machine tool

Static stiffness is one of the most important performance specifications of parallel machines. The static stiffness of a novel 3PRS/UPS redundant parallel machine is analyzed by using ANSYS software. This machine prototype is designed to perform 5-face machining with an active limb to improve the orientation capability of the platform. Stiffness enhancement is studied due to the introduction of a redundant leg to the original machine. From both horizontal and vertical directions, stiffness comparison is carried out when the machine lies at different postures in the workspace. Basing on these results, a better subspace is pointed out for cutting process and this work provides reference for the further revised design of this machine tool.