An efficient and accurate dynamic stress computation by flexible multibody dynamic system simulation and reanalysis

This paper presents an efficient and accurate method for dynamic stress computation based on reanalysis in flexible multibody dynamic system simulation. The mode acceleration concept that is widely used in linear strucural dynamics was utilized for accuracy improvement. A mode-acceleration equation for each flexible body is defined and the load term in the right hand side of the equation is represented as a combination of space-dependent and time-dependent terms so that efficient computations of dynamic stresses can be achieved. The load term is obtained from dynamic simulation of a flexible multibody system and a finite element method is used to compute stresses by quasi-static analyses. A numerical example of a flexible four-bar mechanism shows effectiveness of the proposed method for flexible multibody dynamic systems such as linkages and vehicle systems.