| Title |
Accurate Algorithm of Nonlinear Force-Based Frame Finite Element |
| Authors |
Cho Chang-Geun ; Kim Young-Sang |
| Keywords |
force-based method ; displacement-based method ; finite element analysis ; nonlinear analysis |
| Abstract |
In formulations of nonlinear frame finite element, the shortcoming of the displacement-based finite elements, so called the stiffness method, are their inability to satisfy the equilibrium in the element level by using the displacement shape functions. This assumption leads to inaccurate results of the sectional moment and curvature distributions in highly nonlinear regions. This study presents a force-based frame fiber finite element formulation that can satisfy the equilibrium not only in the element level but also in the structural level. The force-based finite element formulation is based on the force-interpolation functions within the element without using the displacement shape functions. Compared with the stiffness method using some examples for the nonlinear analysis of prismatic and nonprismatic beam-columns, the presented model offers more accurate predictions not only in the load-deflection relationships but also in the distributions of sectional forces and deflections in highly inelastic regions |