Analysis on the Dynamic Responses of Steel Beam under the Condition of Heat and Blast Loads

Numerical simulation and analysis on the responses of steel beam under fire thermal load and blast load are performed using ABAQUS general finite element program. In this study, two cases with different order of applying the fire thermal load and blast load in a different order are considered: 1) when the steel beam is heated by fire first and then is impacted by blast load, the influence of the temperature on the pulse amplitude–impulse (P-I) diagrams is discussed and the saturated impulse and the minimum impulse related to temperature are analyzed. 2) when steel beam is impacted by blast loading first and then is attacked by fire, the influences of the initial static load and the pulse amplitude on the critical temperature-impulse (Tcr-I) diagrams are analyzed. The analysis results show that the higher the temperature is, the lower the impact resistance capability of steel beam is. The saturated impulse and the minimum impulse can be used to measure the impact resistance capability of steel beam. The impulse I(ηD) can be used to measure the fire resistance performance of steel beam. The blast load can obviously reduce the fire resistance capability of steel beam.