Reliability Analysis Of Steel Structure Series System With Potential Brittle Failure Members

In recent years,with the frequent occurrence of earthquakes,people’s lives and property safety have been seriously threatened,resulting in huge losses.As of August 2008,the direct economic losses caused by the Wenchuan earthquake amounted to hundreds of billions of yuan.Among them,building construction losses were the main economic losses.Therefore,it is very important to study and analyze structural reliability from a safety perspective.So far,various reliability analysis methods have been developed.In this study,the steel structure is taken as the object,and the reliability analysis is carried out for the case where the steel structure contains brittle fracture members(ie,potential brittle failure members),and the corresponding reliability calculation method is proposed.In this paper,a comprehensive analysis of the various conditions of steel structure damage is carried out.Taking the series system as an example,the accuracy and efficiency of the proposed reliability calculation method are studied and analyzed.In this paper,the failure probability analysis of structural systems is studied by considering the failure of components and the correlation between components,especially in the case of potentially brittle failure components,based on linear programming boundary method,relaxed linear programming boundary method and Monte Carlo method.main tasks as follows:(1)Through the linear programming boundary method and the relaxed linear programming boundary method,the structural reliability calculation method for the component with potential brittle failure components is established,and the corresponding calculation formula is derived.The rationality of the formula is verified by engineering examples.(2)Based on mathematical calculation software,the failure probability of structural system with potential brittle failure members is calculated by linear programming boundary method,relaxed linear programming boundary method and Monte Carlo method.The applicable range of three methods under different conditions is calculated.(3)Considering the impact of potential brittle failure components on structural safety,comprehensively analyze the impact of series structure failure probability under different conditions.The results show that:(1)In the steel structure series system,the failure probability of the structure containing the latent brittle failure members decreases with the increase of the correlation coefficient,that is,the stronger the correlation between the components,the lower the failure probability of the overall structure;(2)With the increase of the reliability index,the failure probability of the structure with potential brittle failure members is gradually reduced,and the failure probability boundary calculated by the linear programming boundary method and the relaxed linear programming boundary method is gradually narrowed because of the linear programming boundary method and the relaxed linear programming.When the boundary method calculates the upper and lower boundaries of the failure probability,the smaller the failure probability of the structure,the smaller the range between the upper and lower boundaries;(3)When other conditions are certain,in order to reduce the failure probability of the structural system,the safety level of the structure(ie,increasing the reliability index)or the connection between the components may be improved during design;(4)When the total number of components in the structural system is small(n<15),the linear programming boundary method,the relaxed linear programming boundary method,and the Monte Carlo method can be used.When the total number of components in the structural system is n>15,the loose linear programming is adopted.Method,Monte Carlo method,when the total number of components in the structural system is large(n>35),the relaxation linear programming boundary method can be used.This study will be of great significance for the accurate analysis and evaluation of the steel structure with potential brittle failure components.It has certain application value.