Modeling Fracture of Steel at Elevated Temperature

Abstract

This paper summarizes recent research on modeling steel fracture at elevated temperature. Modeling fracture is important for simulating the behavior of steel connections in fire, where fracture of bolts or other connection elements is often the failure mode that controls overall strength and deformation capacity of the connection. In this study, true stress-strain curves for structural steel at ambient and elevated temperatures are first developed that extend beyond necking. Then two widely used fracture criteria (ductile fracture and shear fracture criterion) are studied in order to model steel fracture at ambient and elevated temperatures. Calibration of fracture parameters for these criteria is performed by using finite element analysis together with experimental data. To verify the accuracy of the calibrated fracture parameters, comparisons are presented between the results of elevated temperature connection tests and simulation results.