Performance‐based design sensitivity analysis of steel moment frames under earthquake loading

Abstract

SUMMARYA performance-based design sensitivity analysis procedure for inelastic steel moment frameworks under equivalent static earthquake loading is presented in this paper. Analytical formulations defining the sensitivity of displacements to modifications in member sizes are derived based on a load-control pushover analysis procedure. Material non-linearity under bending moment is alone accounted. Although the formulations were derived based on continuous design variables, they are readily extended to the case of discrete design variables. A 3-storey moment frame example illustrates the applicability and accuracy of the developed methodology.

Adaptive gradual plastic hinge model for nonlinear analysis of steel frameworks

“…[10] as a "plasticity factor" for a plastic hinge in a pushover analysis procedure developed for performance-based seismic design. Gong et al (2005) conducted a pushover sensitivity analysis of steel moment frames under earthquake loading using the plasticity factor. Most recently, extended the concept of plasticity factor to the frame members including shear yielding.…”

“…More recently, refinedand quasi-plastic hinge approaches (Liew et al 1993;Attalla et al 1994) with two-surface yielding criteria were proposed to account for the gradual plastification within steel members. Often, a model was constructed to simulate the gradual softening of plastic hinges whose force point falls within the two yielding surfaces (Chen and Chan 1995;Hasan et al 2002;Gong 2003;Chan and Zhou 2004;Gong et al 2005). It has been illustrated that refined-plastic hinge methods possess the most promise for analyzing large-scale structures with acceptable accuracy with similar computational efforts as a conventional elastic-plastic hinge method.…”

Design Optimization of Steel Moment Frames Under Extreme Earthquake Loading

“…Gong et al [31,32] derived sensitivity analysis formulations for the pushover analysis procedure described in Section 2. For the completeness of this paper, the sensitivity formulations are given briefly in the following.…”

“…These drift distributions are deemed to be nearly uniform and satisfactory for design. It is generally unlikely to obtain an optimal design with f 2 =0 due to the following reasons: 1) the cross sections are discrete variables; 2) the errors in computing sensitivity information are unavoidable [32]; 3) the plastic deflections are extremely sensitive to the change of sectional size (a plastic deflection is usually two orders of magnitude more sensitive than an elastic deflection [31] For member plastification taken as a measure of damage, it is observed from Figures 6 and 7 that damage is somewhat uniformly distributed over all stories of the structures where the frames undergo nearly uniform interstory drift (i.e., as desired, there is no significant concentration of plastic deformation). This phenomenon illustrates the close correlation between the inelastic interstory drift and the structural plastic state.…”

Performance-Based Optimization: A Review

“…One of the challenges in performance-based design is to develop optimal design tools that can be used by structural designers to achieve cost-effective and high performance structures. The performance-based optimal design of frame structures has been reported by researchers (Ganzerli et al 2000;Foley and Schinler 2003;Gong et al 2005;Zou and Chan 2005;Liu et al 2005;Xu et al 2006; Fragiadakis et al 2006). It is recognized that topology optimization of structures offers more material savings than shape and sizing optimization.…”