短語詞組短語stiffness matrix equation 剛度矩陣方程stiffness ordinary differential equation 剛性常微分方程structure stiffness equation 結(jié)搆剛度議程element stiffness equation 單元剛度方程elemental stiffness equation 單元剛度方程stiffness equation west bank 勁性方程式stiffness equation of element 剛度方程shape stiffness equation 板形剛度方程 返回 stiffness equation