Evaluation of Displacement-Based, Force-Based and Plastic Hinge Elements for Structural Non-linear Static Analysis

This paper evaluates accuracies and applicabilities of frame elements constructed by displacement-based (DB), force-based (FB) and plastic hinge (PH) methods for structural non-linear static analysis. The theoretical bases of the three frame elements are compared and the global response (nodal level) and local response (sectional level) of the three frame elements are evaluated. The results lead to the conclusions that more DB elements than FB elements need to be employed to obtain accurate post-yielding global responses in the cases of sections undergoing hardening or zero post stiffness. Both DB and FB elements fail to provide consistent and rational evaluation of the post-yielding global responses in the case of sections undergoing softening. The post-yielding global responses presented by the PH element are strongly influenced by the preset hinge length. The three frame elements present consistent local response results but different maximum responses in most cases. The preferred numbers of integration points to be used in DB and FB elements are also advised from the points of view of both consistency and stability.