Advanced Shape Finding Algorithm of Force Density Method Based on Fem

ABSTRACT: This paper proposes a modified formulation of the force density method by adopting finite element method procedures and replacing each edge of a 3-node or 4-node membrane element with a linear line element. The membrane element model, not the cable-net model, is used for simultaneous shape finding and load analysis. The derived force density matrix has a banded, symmetric nature to ensure its effectiveness in an iterative procedure. By using the nonlinear shape finding option, a number of nonlinear shape finding problems can be solved for each force density mode controlling the shape of the surface. Therefore, it is needs not to use the nonlinear numerical method such as NR or DR method. Therefore, the present research may improve the effectiveness and applicability of the FDM in linear and nonlinear shape finding problems. The following numerical examples will verify the various excellent numerical abilities of the proposed FDM.