The geometric stiffness matrix is composed by the effect of axial force, bending moment and bimoment.
其中几何刚度矩阵由轴向力、双向弯曲和截面翘曲的影响组成。
2
A new point is put forward that transverse bimoment has different influence on the two kinds of cross section thin-walled beams, and on their St-Venant principle conditions.