弹性构件的模态选择对机构动力分析的影响

为在柔性多体系统动力学中引入固定界面动态子结构法 ,将 Craig固定界面法减缩后的系统经过再次坐标变换 ,分离出刚体模态 ,证明能更明确地表达边界影响 ,可以进一步提高减缩效率 ,便于在多体动力学中使用 ,并给出了一个含弹性连杆的曲柄滑块机构算例。分析和计算表明 ,经过了再次坐标变换后提高了减缩效率 ,在一定情况下 ,边界状况对系统影响显著 ,使用表达边界的模态可以提高多体动力学的数值仿真精度

Component modal selection for flexible multi-body dynamics

The fixed boundary component mode synthesis (CMS) method was used to analyze flexible multi body dynamics. A coordinate orthonormalizing transformation was applied after the number of degrees of freedom (DOF) of a discrete flexible body was reduced using the Craig Bampton component mode synthesis method. The coordinate transformation extracts rigid modals from the reduced system, and explicitly represents the effects of boundary constraints. The method increases the efficiency of the CMS method and can be easily applied to flexible multi body dynamics. The method was used to numerically analyze a crank block mechanism. The analyses and numerical results show that this method can be easily applied, will improve the precision and efficiency of the CMS method and will accurately represent the boundary constraints.