梁の3次元大変形の有限要素法解析 (第1報)

理論と定式化

抄録

This paper describes a new nonlinear finite element formulation of a spatial beam element. In the large deformation of a beam, dominant motion is due to the rigid body rotation and the strains are always remaining small. Therefore, using the co-rotational element coordinates, strain-displacement equation is assumed to be linear in these element coordinates and the geometric nonlinearity is considered in the transformation between the element coordinates and the global coordinates. Thus, only the usual linear stiffness matrix is first formulated in the element coordinates, and then the geometric (nonlinear) stiffness matrix is derived from the variation of the transformation matrix.