Cyclic Performance of Concrete Filled Steel Tubular Columns After Exposure to Fire: Analysis and Simplified Model

摘要

A mechanics model is developed in this paper for concrete filled steel tubular (CFST) columns subjected to constant axial load and cyclically increasing flexural loading after exposure to ISO-834 standard fire. The predicted cyclic responses for the composite columns are in good agreement with the test results. Based on the theoretical model, parametric analysis was performed on the behaviours of moment (M) versus curvature (Φ) response, and lateral load (P) versus lateral displacement (Δ) relationship for the composite columns after exposure to fire. Finally, simplified hysteretic models for the moment (M) versus curvature (Φ) response, and the lateral load (P) versus lateral displacement (Δ) relationship were suggested.