Reliability Optimization Analysis Of EMU Hoisting Structure

With the improvement of EMU operation speed,the form of decentralized installation of power equipment is widely used,resulting in an increase in the number of vehicle suspension equipment.Hoisting structure is an important component connecting suspension equipment and car body.In the process of train operation,the working environment is relatively harsh and the load is complex.Once the structure is destroyed,it will seriously affect the operation of EMU.It is necessary to carry out structural performance analysis and optimization design.Taking the water purifier hoisting structure as an example,the static strength analysis,reliability analysis and reliability optimization design of the structure are carried out based on the finite element method,agent model technology and particle swarm optimization algorithm,so as to improve the performance of the hoisting structure and ensure the safe and reliable operation of the EMU.Firstly,in order to improve the reliability analysis efficiency of water purifier hoisting structure,a new reliability analysis method of hoisting structure is proposed based on node coupling technology and response surface method.The geometric model of water purification tank hoisting structure is simplified and its finite element model is established.The static strength analysis and verification of hoisting structure are carried out according to relevant standards.Under the condition of maximum working stress,the node coupling technology is used to model and analyze the strength of the hoisting structure,and the analysis results are verified.The parametric finite element model,considering the uncertainty factors,selects the random parameters for central composite design,and establishes the response surface of hoisting structure strength.Based on the reliability analysis model of hoisting structure strength and Latin hypercube sampling method,the reliability of hoisting structure strength of water purification tank is calculated.The research shows that the structural strength of water purification tank hoisting meets the requirements.The reliability analysis method based on node coupling technology and response surface method has higher efficiency than the traditional reliability analysis method based on contact analysis and Monte Carlo method.Water purifier hoisting structure has high reliability.Secondly,in order to improve the strength performance of the water purification tank hoisting structure,the reliability optimization design of the hoisting structure is carried out based on the combined agent model technology and the improved particle swarm optimization algorithm.The strength sensitivity analysis and screening of design variables are carried out.The third-order polynomial function and radial basis function are used to establish the combined agent model of hoisting structure strength,and the fitting accuracy is tested to obtain the optimal shape parameters.The particle swarm optimization algorithm is improved from three aspects of population initialization,particle update and population update,and its optimization ability is tested.The penalty function method is used to deal with the reliability constraint conditions,and the reliability optimization model of hoisting structure strength is established.The model is optimized based on the improved particle swarm optimization algorithm,and the obtained optimization scheme is analyzed and verified.The research shows that the established composite agent model of hoisting structure strength has high fitting accuracy.The improved particle swarm optimization algorithm improves the optimization accuracy,convergence speed and stability.After optimization,the working stress of the water purification tank hoisting structure decreases,and meets the reliability constraint requirements.The optimization improves the structural strength performance to a certain extent.Finally,in order to improve the strength performance and lightweight level of the water purifier hoisting structure,the multi-objective reliability optimization design of the water purifier hoisting structure is carried out based on the improved multi-objective particle swarm optimization algorithm.The multi-objective particle swarm optimization algorithm is improved from the three aspects of optimal particle selection,external archive set maintenance and population diversity maintenance,and its optimization ability is tested.Aiming at the strength and overall quality of hoisting structure,a multi-objective reliability optimization model of hoisting structure is established.The model is optimized based on the improved multi-objective particle swarm optimization algorithm,and the final optimization scheme is selected and analyzed.The research shows that the improved multi-objective particle swarm algorithm has faster calculation convergence rate and better solution set distribution uniformity.After multi-objective reliability optimization,the working stress and overall mass of the hoisting structure are decreased,and the reliability constraint requirements are met.The optimization improves the structural strength performance of the water purification tank and achieves the purpose of structural lightweight.