Dimensionless approach for transient behaviour of flexible body with time-varying length

Abstract

In this study, transient analysis of flexible body motion with time-varying length is conducted using dimensionless finite element model (FEM). First, the equation of motion for a flexible body with large deformation, displacement and time-varying length is derived by VFE-ANCF, which variable-domain finite element model (VFE), a model expresses length change, applied to absolute nodal coordinate formulation (ANCF), known as an effective nonlinear finite element method in dynamic flexible body simulation. Then the equation of motion in dimensionless form is derived using dimensionless variables defined by time-varying length of the flexible body as a representative length and a representative time considering the longitudinal frequency of the flexible body. The system is converted into the system that length of flexible body is always constant by using this representative length. So, this method avoids the problems with analysis accuracy and calculation cost when the length becomes shorter and the natural frequency increases. Furthermore, the numerical results clarify the mechanism of flexible body motion with time-varying length.

Keywords

• multibody dynamics
• flexible body
• numerical analysis
• transient analysis
• non-dimension