Research On The Lightweight Design For Frame Structure

With the increasing number of cars in the global, the problem of the environmentalpollution and the energy shortage is more and more serious and the vehicles for lightenergy-saving and environment friendly become a focus in research and development ofautomotive industry today. As an important structure of auto parts, the vehicle frame has agreat quality and supports a variety of complex loads from road and load, and the structure ofthe performance affects the normal driving. Therefore, in the premise of adequate strength andstiffness, the lightweight design of frame has important theoretical significance and practicalvalue.In the way of frame lightweight, technology and funds severely restricts the applicationof new materials and new manufacturing technology, the improvement design of the structurebecomes an important technology method of lightweight. In the design and analysis ofstructure, finite element method (fem) analysis and calculation can simulate the actualworking situation of the frame very well, and basically solve the difficulties of the analysisand calculation of complex structure parts, fundamentally change the traditional designmethod based on experience.Based on the analysis and summary of the research on frame lightweight status at homeand abroad and the research of the lightweight design method of automotive, this papersummarizes the lightweight design approach of the general frame in structure, and selects atype of truck frame as an engineering example for analysis and verified. According to theactual structure of the truck frame, the three-dimensional entity model is set up in theapplication of UG software. The finite element analysis model of the truck frame isestablished after cleanup geometry, mesh, the simulation of connection method and theboundary condition on the basis of using hypermesh platform. Through loading and set constraints in the finite element model of frame, the strength and stiffness analysis was doneusing finite element theory and the OptiStruct platform, and draws the stress concentrationareas and the maximum displacement position on frame, and evaluates strength and stiffnessof the frame structure, the results show that the strength and stiffness of frame meets theconditions of use and there is a great potential of lightweight. According to the theory for thestructure optimization, the mathematical model for lightweight design of the frame isestablished by defining the optimization variables, constraint function and the objectivefunction. Based on the OptiStruct platform, the designs of size optimization and shapeoptimization were done, the results show that the quality of the frame after optimization wasobviously less than the original and achieve the purpose of the lightweight design, and itproves that the lightweight approach of the general frame in structure is feasible.