Lightening And Strength Optimization Of Autocar B Pillar With New High Strength Plate

With the convening of the Copenhagen Climate Conference, people have increased interest in greenhouse effect, especially vehicle gas emissions, and vehicle body weight relief can improve fuel economy, therefore, vehicle lightening become the focus of Automotive Research. Car body is one of three assemblies (engine, chassis and body) which takes 40-60 percent of the whole vehicle weight. So, it is significant and practical to lighten structure weight in car body design.Performance of high strength materials has great influence on lightweight, is also the key to lightweight. In this paper, B pillar is made thinner and lighter by using the high strength steel plate with the hot molding technology to replace ordinary high strength one, in the premise of invasive capacity and speed indicators not decreasing compared to the original program. At first a whole vehicle model is established and the side impact calculation is processing, then B pillar simplified model of the side impact is established with the boundary of the B pillar added whole vehicle model displacement curves to and the mobile barrier added velocity curves to, before the verification of the high reliability; the lightweight model without the reinforced sheet and reducing 25% of B pillar quality is designed with this simplified model, the results show that lightweight model has still effectively controlled invasive capacity (displacement), but the invasive speed has increased, so it is necessary to achieve a reasonable optimization of absorption and distribution of B pillar energy.It is an effective optimization method that the B pillar is bed along the axial, then the strength is optimized with the orthogonal experiment. In this article, B pillar is divided into five layers, set up a 5 element 4 level 16 orthogonal test table, and the relative best combination can be selected by comparing invasive capacity and invasive speed of the results, then the relative best combination result is assessed. After verification of the whole vehicle model, the results show that this B pillar Optimization method is reliable and stable through the establishment of orthogonal experiment, the invasive speed is effective controlled under the reasonable energy absorption, as the invasive capacity is not bigger than the one of the original program.