2002 年 2002 巻 p. 20020026
I proposed the finite element formulation using SO(3) and Linear stress rate before. The tangent stiffness using this stress rate is much simpler and easier to get for the beam and the shell elements than any others. Then, the new membrane element is developed according to this formulation. It has the strong point that there are 3 rotational degrees of freedom at each grid point. So, the elimination of the in-plane rotational degree of freedom is not necessary when 3-dimensional analysis is executed. In this paper, the theory limited to linear stiffness is shown and the results of benchmark tests are shown.