Lightweight Optimization Design For Safe Components Of Body-in-white Front Structure

Since the1980’s, China’s auto industry gets fast and rapid development. Because ofeach big auto companies expanding their business and the market, also and national policystrengthening the support in auto companies, China’s auto industry ushered in the goldenperiod of development. Since the end of the20th century, and the amount of people whohave cars continues to grow in China. Having cars bring great convenience to our daily lives,but also have caused the energy consumption and environmental pollution problems. Sothere is an urgent problem to be solved that is how to reduce the fuel consumption andemission. According to some experts and scholars, when vehicle weight is reduced by10%,the fuel can be decreased8%~10%.Automotive light weighting is one effective way to reduce fuel consumption andemission, and also an effective method to improve the car market competitiveness. SoAutomotive light weighting plays an irreplaceable role in improving each huge carcompany’s core competitiveness, and also has important significance in energy strategy andthe sustainable development of the automotive industry.Lightweight car body has now become the focus and hotspot in the research of theautomotive industry. In this article, I made a lightweight design to the safety components ofthe front structure in the situation that ensures the body-in-white being touched withoutreducing security and verified the reasonableness of the lightweight program by comparingthe body-in-white after weight loss and original body collision.Firstly, building the frontal crash safety model of the original body-in-white isnecessary. Use Ls-dyna software to simulate the situation that original body-in-white impactthe fixed rigid wall along the X-axis negative direction of the level, at the speed of50km/h.Then obtain the structural deformation and stress cloud diagrams of original body-in-white during the collision. Extract the energy-time course curve of the original BIW anddisplacement, velocity and acceleration time history curve of nodes592975and661210inthe deformation process. After a simple calculation, I get energy absorption ratio, the amountof front-end crush and peak acceleration parameters during the collision.Secondly, obtaining the crashworthiness of hexagonal cross-section is better thanrectangular cross-section by comparing the crashworthiness of rectangular and hexagonalcross-section thin-walled tube. And then the cross-sectional shape of front rail is designed tohexagonal. I apply the Material alternative to the theory of axial crashworthiness to draw thevalue of the reference plate thickness of material substitution in the weight loss process.Designing the test number by orthogonal test and analysis test results by R-means, and thenobtained final weight loss program of the front safety components.Finally, using the crashing simulation the body-in-white after weight loss, extracting thevarious results parameters in the collision process and comparing energy absorption ratio,the amount of front-end crush and peak acceleration parameters of the original BIW is toverify the reasonableness of the lightweight program.