Dynamic analysis on rigid-flexible coupled multi-body system with a few flexible components

The analyzed multi-body system is a complex mechanism whose component rigidities are quite different. If the multi-body system is considered as a rigid multi-body system to analyze its dynamic characteristics, false analysis results will be caused by ignorance of elastic deformation. If it is completely considered as a flexible multi-body system to establish the model, analyze and solve, the system equations are quite large which make them difficult to solve. The feasible method is as follows: the complex mechanical system is divided as a rigid-flexible coupled system with a few flexible components and an equivalent system. The equivalent system is formed by making dynamic characteristics of rigid components and elements to be equivalent. Then the equations are established according to the flexible multi-body system´s way and the system equation dimensions are reduced by introduction of transition matrixes. Taking a harbor crane´s jointed arm crane mechanism as an example, a modeling method for rigid elements and flexible elements coupling is presented, the rigid elements and rigid constraint conditions are introduced, the system model is reduced based on the flexible multi-body system and analysis efficiency is improved greatly. The feasibility and availability of rigid-flexible coupled system dynamic analysis method are verified.