THE EFFECT OF MATERIAL CONSTITUTIVE MODEL ON SEISMIC RESPONSE OF CONCENTRIC BRACED FRAMES

Based on seismic design provisions, earthquake-resistant structures are allowed to dissipate seismic energy through inelastic behavior. Thus, the designer must be aware of the material behavior in the inelastic range to estimate the true performance of the designed structure. Effects of the chosen stress-strain constitutive model as well as the behavior of steel in the strain-hardening range may be significant on the actual seismic response of the structures. In this article, seismic response of concentric braced frames is studied considering the aforementioned parameters. Nonlinear analyses based on actual stress-strain curve of structural steel, shown in Figure 1, is rather complex andtime-consuming; instead, simplified models of different types are generally used to avoid this complexity. As shown in Figure 2, each of these models includes some simplifications that may affect the results of analyses considerably

Keywords:

Steel material model , Nonlinear time history analysis , Seismic response , Cable bracing , Strain hardening