Reliability Analysis Of Parallel Steel Structure System With Potential Brittle Failure Components And Its Application

Steel is generally regarded as a pure plastic material due to its high strength,good ductility and good material toughness,etc,and is widely used in engineering structures.However,brittle failure of steel structures occurs from time to time in steel structure failure accidents all over the world.Therefore,it is necessary to study the brittle failure of steel and its impact on the structure,and evaluate the safety of building structures,so as to better protect people's property and personal safety.Based on the safety of the structure and the reliability analysis of the structure,this paper studies the calculation method and variation rule of the failure probability of the parallel steel structure system containing the potential brittle failure member.In this paper,according to the different failure modes,the parallel steel structure system with potential brittle failure member can be divided into two cases:instantaneous failure and successive failure.The failure characteristics of parallel steel structure system under these two failure modes are studied respectively.According to the change of the number of brittle failure members,the mathematical model of failure probability of parallel steel structure system is established,and the calculation method of failure probability is summarized.Based on MATLAB software platform,the failure probability of the system under two different failure modes of instantaneous failure and successive failure was calculated.The relationship between the failure probability of the system and the basic parameters is analyzed,and the difference between the failure process and the failure probability calculation results of the parallel steel structure under the two failure modes is compared.Using LP bound method and Monte Carlo simulation method,the validity and applicability of the results of RLP bound method are verified.By comparing the calculation results of several engineering examples and summarizing relevant laws,the following conclusions are drawn:(1)Not only the possibility of plastic failure but also the possibility of brittle failure should be considered.Based on the brittle failure of steel,this paper proposes to analyze the parallel steel structure system into two different failure modes:instantaneous failure and successive failure;(2)Based on the reliability calculation method,RLP bound method is recommended in this study to calculate the failure probability of parallel steel structure system.Using LP bound method and Monte Carlo simulation method,the validity and applicability of RLP bound method are verified;(3)Synthesizing the relevant test data in this paper,we can see that the failure probability of the parallel steel structure system is proportional to the occurrence probability P_biof the brittle performance of the member,inversely proportional to the total number of members n,proportional to the correlation coefficient?between the members,inversely proportional to the reliability index?of the system,and proportional to the number n₁of the potential brittle failure members.Parallel steel structure system are analyzed in this paper the two different failure modes,and summarized the failure probability with the basic law of parameter changes,and puts forward the potential of brittle structures containing parallel steel structure system reliability calculation method,and the reliability of the parallel steel structure system research provides the theoretical basis,to contain the potential of brittle structures of steel structure system research provides data support,has certain application value.