Modeling and simulation of flexible axially moving arm

A finite element method is developed for modeling and simulation of flexible axially moving arm, considering the effects of Coulomb friction, the elasticity of the entire arm and the clearances between the arm and joint. Mechanical interactions between the arm and joint are simulated by a model which is formulated based on the penalty method. The the contact forces are calculated based on the contact model, trial-and-error algorithms. Based on the obtained contact forces, the system dynamic equations are numerically solved by Newmark method. A numerical example is simulated to show the capability of the new method. The obtained results also reveal that it's inappropriate to ignore the influences of friction force and the small deformation of the arm part inside the joint. The method should prove useful in designing and controlling mechanical systems with axially moving arm.