Discussion of "Proposed Updates to the ASCE 41 Nonlinear Modeling Parameters for Wide-Flange Steel Columns in Support of Performance-Based Seismic Engineering" by Dimitrios G. Lignos, Alexander R. Hartloper, Ahmed Elkady, Gregory G. Deierlein, and Ronald Hamburger

Ronald Hamburger I congratulate the authors for their truly impressive and thorough empirical regression analyses using data from 151 lab tests in developing first-cycle envelope curves (backbones) for use in nonlinear component modeling. Backbones are dependent on the test data used in the formulation, and the authors note that the first-cycle envelope curves are load-history dependent. The purpose of this discussion is to supplement the authors' work by examining the influence of lab test load history on test results that in turn affect the derived backbones. [Extracted from the article]