Lightweight Design and Study of C2Sedan Body in WhiteCN
Abstract：Lightweight design of body in white is of great importance in reducing automobileexhaust emissions and energy consumption. So the lightweight design of body in whitehas become one of the major research directions for the car manufacturers. The mainmethods of the lightweight design of body in white are: technology of structureoptimization, technology of novel materials and technology of advancedmanufacturing.Structure optimization technology has got more widely used and valuedin condition that it will not significantly improve the automotive product cost.This paper studied the topology optimization technology of the structureoptimization and the static stiffness test of body in white.The main contents are asfollows:The traditional topology optimization is just a part of body in white separateoptimization, such as the location of the holes on parts of the weight loss selection andsize optimization.This ignores the whole vehicle condition and can not fully dig thepotentials of the lightweight of body in white.This paper based on the theory of topology optimization,with reference to thewhite body prototype of C2sedan, using CATIA software to build its3D model, andusing Hypermesh software to build its finite element model and finish thepre-processing.The constraint conditions were set based on the static stiffnesscharacteristics of the white body.This paper choose white body weight as the objectivefunction, and choose the thickness of large-scale plate parts and significant beamstructures of body in white as design variables, and use Nastran to do the iterativecalculation with these design variables, and put forward specific optimization schemeaccording to the stress nephogram and simulation data.Because of the difference between computer simulation environment and actualsituation, it is necessary to conduct experiments to verify the feasibility of theoptimization. In this paper, with the improved white body according to theoptimization,some experimental studies were conducted on the static stiffness testbench. The static stiffness values of the white body is obtained through the relativetorsion angle, torsional stiffness curve, bending stiffness curve and the wind windowdeformation of each measurement point.Through comparing the experimental resultswith the simulation optimization results, the error is less than10%, which verifies theeffectiveness of the topology optimization results.