Stiffness Reduction of Steel W-Shapes: Comparison of New Inelastic Material Model with the AISC Inelastic Material Model

This paper focuses on illustrating the effectiveness of the new material model, 𝜏𝐵𝑇𝑅 in comparison with the Specifications for Structural Steel Buildings (2016) material model, 𝜏𝐴𝐼𝑆𝐶 , against a detailed finite element model to determine the accuracy of modeling the inelastic behavior of steel W-Shapes. A total of seven steel columns were analyzed, using a W8x31 section, and eleven benchmark frames to compare the performance of the two material models. An ultimate strength study was conducted using the following slenderness ratios, L/r, of 40, 60, 80, 100, 120, 160, and 200 and oriented such that minor-axis bending occurs. The benchmark frames were modeled under a limit load analysis to illustrate the magnitude of stiffness reduction considering both major and minor-axis bending. Lateral displacements were recorded and compared for the eleven frames up to the collapse condition. Additional information is provided discussing the capabilities of the two material models and their performance when compared to a detailed finite element model.