Refined Physical Theory Model for Predicting the Seismic Behavior of Braced Steel Frames

摘要

This report presents a state-of-the-art model for inelastic response analysis of braced steel structures. This model achieves realism and efficiency by combining analytical formulations describing plastic hinge behavior with empirical formulae based on experimental data. Several empirical behavioral characteristics are implemented in this modeling including (1) the variation of the tangent modulus of elasticity during cycles, (2) the gradual plastification process of the plastic hinge, and (3) the residual displacement due to material nonlinearities in the nominal elastic range. Verification of the new model is performed on the basis of quasi-static analyses of individual struts and dynamic response analyses of a three-story X-braced steel frame, representative of offshore platforms. The model is applied to the study of the design of a real sized six-story K-braced steel building frame.