Time-dependent Reliability Study Of Crane Jib Structure Based On Interval Non-probabilistic Model

With the wide application of crawler crane is applied to various engineering fields,the jib structure as the core parts of the crane reliability is got more and more attention.The traditional reliability model is based on the theory of probability and fuzzy mathematics,which requires a large amount of sample information to define the probability distribution and membership function of uncertain parameters.But crawler crane is small batch production,and the experiment cost is relatively large,it is difficult to get a large number of sample information by traditional reliability models.When the sample information is insufficient,the non-probabilistic reliability model is a very good complement the former two models.Due to the environmental factors and the change of the material itself,the resistance of the frame structure will decrease with time,and its reliability is no longer a fixed value.This paper aims to study the non-probabilistic reliability of crawler cranes under limited sample conditions in the case of insufficient sample information for uncertain parameters that affect structural safety.And the effect of the theoretical model and the method of solving the non-probabilistic reliability of time-dependent resistance degradation and time-delay are proposed.The main research contents include:(1)Based on the theory of interval non-probabilistic,a new reliability model and method of the reliability of crawler crane are proposed,and the uncertain parameters are described quantitatively by interval.By analyzing the relationship between the limit state function of the jib structure and the feasible region of the uncertainty parameter,the safety and reliability degree is determined.(2)By considering the time-dependent degradation of structural resistance and the time-dependent effect of load,the time-varying uncertainty parameters in jib structure are analyzed synthetically,and the first time span in stochastic process theory is used to calculate the time-reliability model,and the solution method is given.(3)By using VC ++ programming to parameterize some variables,calculate the static reliability and time-varying reliability of jib structure.The effects of different weights and uncertain parameters on the reliability of the static structure of the jib are studied.At the same time,the variation of the resistance of the jib structure at different times is calculated.Through the analysis of engineering examples,proves the feasibility of a certain reliability based on interval non-probabilistic model to study the crawler crane,this study provides a reference for reliability analysis of other large engineering machinery.