Sensitivity based Reliability Analysis of Steel Moment-Resisting Frame Structures under the Impact of the Heavy Vehicle Collision

Over recent decades, regarding the spread of unusual events such as fires, explosions, and vehicle collisions, the study of the behavior of structures subjected to abnormal loadings has been taken into account by the researchers and structural engineers. In this study, 2 and 5-story steel moment-resisting frame structures have been considered under the heavy vehicle collision impact. They are modeled in OpenSees software two-dimensionally with regarding to uncertainty in materials and applied loads and the sensitivity based reliability analysis of the studied random parameters is performed in Matlab software. Then, the effect of each of the variables is investigated using simulation-based methods according to limit state functions based on the maximum permitted beam rotation of damaged bay of frames. The results of this study presented that the random variables such as mass and velocity of vehicle and yield strength of material were the most influential parameters in calculating the failure probability in representative structures. Also, the control variates-based subset simulation (CSS) method compared to Monte Carlo Simulation (MCS) approach estimated the failure probability with permissible error rate, less sample number and the minimum computer processing time duration. Furthermore, the results of this research indicated that by increasing the number of stories of the building, the probability of its failure due to vehicle collision increased. According to the results of this study, the value of beam rotation of damaged bay parameter of the 5-story frame compared to 2-story one has increased by 55, 18 and 33% under the LSF1, LSF2 and LSF3 functions, respectively