Structure Optimization Of Automotive Door Inner Panel Using Multi-material Construction

In recent years, the number of retained automobiles is increasing. With theimprovement of social civilization and the limited availability of renewable energy,environmental protection and resource conservation have become the two importantproblems of automotive industry all around the world and even in our nation.Lightweight of vehicles is the most effective way to reduce fuel consumption andemissions. Weight reduction of the vehicle plays an extremely important role inimproving automobile fuel economy. As an important assembly of car, the lightweightof the door plays an important role in reducing vehicle’s weight.In the exploration of reducing cost and lighting weight, this paper designs a kindof automotive door with divided inner panel using multi-material and a structuredesign method is raised, following the idea that suitable material should be used inappropriate position.First of all, the geometric model of the door is cleaned in HyperMesh and thefinite element model is established, then the quality of grids is checked. Assemble thecar door as the actual situation and endow it with material properties and thickness.Identify the examining indicators of the car door. Constraint and load for the car door.The finite element analysis of the car door using single material is carried out inMSC.Nastran. Through the analysis of calculation results, find that stiffnessperformance of the door has a large space to optimize, modal performance is alsoavailable.According to the results of the analysis of the original car door using singlematerial, the divided automotive door inner panel is put forward. According to theneeded intensity, different inner panels are given different materials following theidea that suitable material should be used in appropriate position. Through theanalysis of performance of new door, its stiffness and modal performance can’t meetthe requirement. They should be improved by structural optimization.According to the result of the analysis of car door using multi-material,optimized its structure to promote the performance with OptiStruct. Calculate themost reasonable force transmission path by topology optimization, and add thereinforcing plate to improve its stiffness; Calculate the most reasonable stampingreinforcement by topography optimization, and add it to improve its modal frequency; Calculate the best thickness of the car door inner panel, make it lightweight, and makethe utilization of materials more reasonably by size optimization and sensitivityanalysis.Finally, different performance and quality, as well as manufacturing cost arecarried out by comparing the multi-material door with single-material door.