Nonlinear Deformation of a Shear-Deformable Laminated Composite-Material Flexible Robot Arm

Abstract

In this work a general procedure to derive a nonlinear dynamic model for a three-link revolute flexible robot arm constructed from laminated fiber-reinforced composite materials is presented. The effects of geometric nonlinearity as well as rotary inertia and shear deformation are included to study the dynamic response of robotic manipulators made of moderately thick beams under large deformations. Hamilton’s principle is used to derive the equations of motion. A displacement finite element model based on the Timoshenko beam theory is implemented to approximate the solution. The digital simulation studies examine the combined effects of geometric nonlinearity, rotary inertia, and shear deformation on the arm’s end effector displacements. Furthermore, the effects of angle of fiber orientation and material orthotropy on the end-of-the-arm displacements and maximum normal bending stresses, are assessed.