Lightweight Of Automobile Structural Based On Tube Hydroforming

In recent years, with the demand for automotive of energy saving, more and more automotive lightweight methods is come up. There are two important way to achieve it, adopting new lightweight materials and using advanced manufacturing technology. The tube hydroforming technology have many advantages, such as, reduce the part weight, improve component strength and stiffness, better crashworthiness performance, materials saving, fewer processing steps, low production cost, it is currently be widely used in global automotive manufacture. Although the tube hydroforming technology compared to traditional manufacturing technologies have obvious advantages, but in the domestic it is still in the infancy, the lack of adequate research experience for the design and manufacture of tube hydroforming member, currently the application of tube hydroforming products are less. Therefore, product design and prototyping research based on tube hydroforming significant importance.The crash box of automotive is an important buffering and absorbing structures, aim to protect the vehicle body from damage and keep passenger safety. In this paper, the study object is the front crash box of an SUV, design tube hydroforming crash box replace the original one. The main contents are as follows:1. Based on RCAR front text, use numerical simulation software to establish vehicle collision model, collision results were analyzed to assess the performance of crash box.2. Establish the original crash box drop hammer impact text finite element model based on RCAR text. Compare with the vehicle collision of crash box deformation and load curve, obtain that using the drop hammer impact simplified model alternative vehicle model has better accuracy and computational efficiency.3. Design tube hydroforming crash box based on original one, establish the crash box drop hammer impact model include size and shape parameter based on RCAR text, application of modern optimization methods Sequence two programming for optimal value, then, ultimately gain a new crash box of lightweight and better performance of collision energy absorption.4. Molding feasibility analysis of the tube hydroforming crash box to determine its eligibility load range. Analysis the influence of load paths on the forming quality, conclude that load paths has effect on thickness distribution and minimum wall thickness for forming member. Select important load path control parameters as design variables, use Hamersley sampling to build experiments, establish an approximate model using the Kriging method, finally, adopt adaptive response surface method to optimize the control parameters of load path. Reduce the minimum wall thinning rate of crash box, and improve the forming quality.