利用刚度影响系数法求刚度矩阵k312111由平衡条件得到mglkh21kh画出受力图并施加物体32221212kh32kh画出受力图并施加物体33231323khmglkh33题4567则刚度矩阵和质量矩阵分别得mglkhkhkhmglkhkhkhmglkhmlmlmlmpmglkhkhkhmpmglkhkhkhmpmglkhmlmglkhkhkhmlmglkhkhkhmlmglkh展开为mpmglkhmpmglmpmglkhkhmpmglkhmpmglkhmpmglk...