Optimization Design Of Metro Car Head Structure Based On OptiStruct

Composite materials have been widely used in aerospace,automobiles,and ships,but their application in rail vehicles is still in the stage of development and exploration.With the continuous improvement of metro vehicle technology,the performance of the front has also received more attention,and at the same time put forward higher requirements for vehicle lightweight.Traditional single-component structural materials are difficult to fully meet the above requirements,so it is necessary to study the application of composite materials on the front of subway cars.By utilizing the excellent properties of the new composite materials,material ratio and laminate design combined with structural optimization,the reliability,safety of components,maintenance and repair costs can be reduced,and the weight of the structure can be further realized.On this basis,this paper uses finite element theory,classical laminate theory,structural reliability theory and structural optimization design theory,and uses the means of simulation analysis to analyze the performance and structure optimization of the subway car front.Main tasks as follows:(1)Simulation analysis and optimization of structure performance of subway car front.According to the given related data and geometric model,the finite element model of the front is established,and the static strength analysis of the front is performed under the eight conditions using the OptiStruct solver.At the same time,using the Monte Carlo method based on Latin hypercube sampling,the reliability analysis of the sub-model of the ankle structure is carried out,and the failure probability of the ankle is high.Based on this,in order to reduce the failure probability of the structure,the ankle weighting flexibility value is used.Minimization is the goal,and its quality is the constraint.Based on OptiStruct,the size of the ankle structure is further optimized.The optimization results show that the optimized ankle structure satisfies the reliability requirements.(2)Equivalent design of composite head cover.Based on HyperLaminate composite material modeling technology,the finite element model of glass fiber front cover is established,and its structural performance analysis under mechanical dynamic load and wind pressure conditions is carried out.The material ratio optimization of the head cover is carried out by the method of equal generation design,and the layers of the original glass fiber head cover are redesigned under the same load by using three layers of all-carbon fiber,glass-carbon intermixing and glass-carbon sandwich mixing.Under the working conditions,the finite element simulation optimization analysis of the front cover layers of the three ply schemes is carried out,and the strength of the composites is verified by the Cai-Wu failure criterion.Finally,the economics,weight reduction effect,mechanical properties and environmental protection are compared.The latter two paving schemes are the initial scheme for further structural optimization design of the front cover.(3)Structural optimization design of composite head cover.In order to give full play to the potential of lightweight composite materials,based on the results of the equivalent generation design,the head cover is further optimized for the layup,and the mathematical model and the optimization criterion method are used to establish the approximate explicit model of the front cover and optimize the solution by solving the sensitivity.Decoupling of the target,the weighted compliance,mass and layup order of the head cover are the objective functions,with the volume fraction,displacement,and composite strain as the constraints,respectively,the hybridization of the glassy carbon interlayer and the glassy carbon sandwich.The front cover is optimized for free size,optimized for size and optimized for the layup sequence,resulting in optimum layup thickness and layup order for the front cover.The optimization results show that the optimized front cover achieves the goal of weight reduction under the conditions of meeting mechanical properties and various process requirements.