Crashworthiness And Energy Absorption Characteristic Analyses Of Thin-walled Structures In Vehicle Body

The Finite Element Method (FEM) has been widely used in vehicle design. Frontal and side impacts of thin-walled beams are analyzed by LS-DYNA. In frontal impacts, factors such as sectional dimension, welding form, guide slot (shape, dimension and position), ribs and slope angle are analyzed; In side impacts, factors such as sectional dimension, thickness and form of impactor are analyzed. By comparison, the following conclusions are reached: In frontal impacts, the quadrate beam is a better choice for energy absorption, welding factors have the least effects to the symmetrical welding ones, guide slots can greatly reduce the peak force and the triangular ones performs better, ribs are useful in energy absorption and tapered beams can sustain much larger slope angle than the straight ones. In side impacts, beams perform better when their side dimensions are increased,thickness may also do but will result in greater increase in weight and forms of impactors have no influences of the results in essence. Furthermore, frontal impacts and impacts based on the crash law of a simple-structured bumper are performed. Results shows: To the bumper, its frontal energy absorption ability is somewhat poor and the crash law simulation has certain realistic uses. Meanwhile, the peak force which has been found in the thin-walled beams frontal impacts disappears in the results of the bumper frontal impacts; At last, side impacts of a vehicle side door are performed. To the side door, its structure is a little weak and can be improved by adding beams to it.