Research On Frontal Impact Characteristics Of Front Rail Structure Of A SUV

With continuous development of modern automotive technology, traffic accidentshave become a worldwide social problem. In design stage, the impact passivenesscharacteristic and protecting passengers of vehicles structure need to be studied. As thefront rail is the main component for energy absorbing in the frontal impact, the form ofdeformation and energy absorbing property affect the vehicle impact performance directly.Therefore, further study of the structure characteristics of the front rail and reasonabledesign of the structure form of front rail has great significance to the protection ofpassengers.First, a SUV as research object, using Hypermesh to establish finite element model ofthe frontal impact, LS-DYNA is used as a solver for simulation and analysis. According tothe high acceleration peak of B pillar, the structure of the front rail was optimized. Theoptimization program includes, tapping induced hole, tapping induced tank, tappingin-plane hole, etc. Results-based program analysis and optimization，induced hole on theedge of the front rail have the best performance, and the number of induced hole havelittle effect on frontal impact. The single row of holes play a good local effect ofweakening.Multi-objective optimization was applied, while the acceleration center of mass andenergy absorption was considered as objectives. The Response Surface Method is suitablefor this question. In succession, the response surfaces was used for optimization while fit afunction of design variables and design objectives by least-squares. After objectivefunction is optimized by MATLAB, optimal value of the front rail tilt length, the distanceof the openings to the front midline, hole width and hole depth was obtained.After the simulation of the improved front rail scheme substitution of the SUV iscompared with the original model, it verified the feasibility of the scheme.