VIBRATION MODELING OF PARALLEL KINEMATIC MECHANISMS (PKMS) WITH FLEXIBLE LINKS: ADMISSIBLE SHAPE FUNCTIONS

摘要

The accuracy of various admissible shape functions, for vibration modeling of flexible links of Parallel Kinematic Mechanisms (PKMs), is investigated as a function of the ratio of the mass of the moving platform to the mass of the link. Knowing that the commonly used shape functions based on "pinned", "fixed", or "free" boundary conditions do not incorporate the moving platform mass, "pinned-mass" and "fixed-mass" shape functions are presented herein, and are compared with finite-element based results for various mass ratios. The closest shape functions to the finite-element results are, then, utilized and compared with other shape functions in the subsequent vibration modeling to predict the tooltip response.