Seismic Behavior of Open‐Web Truss‐Moment Frames

Abstract

This paper investigates the behavior and performance of open‐web truss‐moment framing system under cyclic loading. An open‐web truss‐moment frame of a four‐story building was designed as an ordinary moment resisting frame (OMRF) for this investigation. Three full‐scale, half‐span subassemblages from this building were tested under severe cyclic deformation to determine their hysteretic behavior. Based on the experimental results, a simple analytical model for inelastic cyclic behavior of open web truss frames was developed. This model was used to analytically evaluate the behavior and performance of the four‐story building subjected to several severe earthquake excitations. The system performs poorly because of buckling and fracture of the web members, which led to unstable hysteretic loops.