Reliability Optimization Design Of Bridge Crane Beam Based On Moth-Flame Algorithm

Crane is known as the "symbol of force and beauty",is to reduce the heavy manual labor,improve the efficiency of the project,to achieve the safe production of the lifting equipment.The metal structure is the main load-bearing component of the crane.It is the "skeleton" of the crane.It mainly supports and transmits the working loads,natural loads and self-weight loads borne by the crane.Therefore,reasonable design of the crane's metal structure plays an important role in the overall performance important role.The traditional crane structure optimization design is deterministic design,but in engineering practice,there are some uncertainties in the parameters of crane structure,the reliability analysis is one of the effective methods to solve the uncertain problems.The non-probabilistic reliability interval model only needs to obtain the boundary of the parameter.Its model is simple in construction and the calculation is litter,so it has strong applicability.Based on the reliability analysis of interval models,a non-probabilistic reliability optimization design method based on intelligent algorithm is proposed to optimize the reliability of cranes.Firstly,through the analysis of the basic principle of Moth-Flame Algorithm,aiming at the moth's behavior has much random states and need to repeatedly test in the algorithm,which takes a long time,improved the flame quantity update mechanism and endowed the moths with learning ability.A new AdaptiveLearning Moth-Flame algorithm is proposed in this paper.Secondly,based on the non-probabilistic reliability interval model,researched the non-probabilistic reliability index based on the Moth-Flame algorithm.This paper combines the idea of constrained optimization into unconstrained optimization in penalty function method to improve the objective function,which is more conducive to optimization calculation.Then,explored the interval dispersion of the design variables of the limit state function influence on the non-probabilistic reliability index based on the control variable method.Deduced the function relationship between the design point,the mean,interval dispersion and the reliability index,established a mathematical model of dispersion and reliability index.Finally,in view of the reliability optimization design is double nested optimization design,aiming at this problem,the inner reliability analysis using MATLAB internal function:Vpasolve,optimize the structure of the outer layer using the Moth-Flame algorithm,established a reliability optimization design model based on Moth-Flame algorithm.Based on the Moth-Flame algorithm and considering the uncertainty of the crane structural parameters,this paper optimizes the non-probabilistic reliability of the crane girder structure.The optimization results show that the cross section area of crane girder increases with the increase of reliability requirement,and successfully seeks the optimal balance between the crane cost and reliability requirements.The method has certain theoretical significance and engineering practical value for the reliability analysis and reliability design of complex structures.This method has certain reference value and significance for the reliability analysis and reliability optimization design of complex structures.