Optimization Lightweight Design Of Automobile Bumper Beam Based On Crash Safety

Today,the number of cars in the world is increasing day by day,leading to frequent vehicle collision accidents,the continuous reduction of non-renewable resources,and the rapid deterioration of the environment.To improve vehicle safety and implement energy-saving and environmental protection regulations and policies,the crashworthiness and lightweight of vehicles have attracted great attention from governments,enterprises,and research institutes.The bumper anti-collision beam is a key safety bearing structure in the body assembly,which has an important impact on the crashworthiness and safety performance of the vehicle.Therefore,the research in this paper is mainly aimed at car bumper anti-collision beams,comprehensively using finite element numerical simulation,model parameterization,experimental design,neural network approximate model and intelligent optimization algorithm,and other technical means to design the car bumper anti-collision beam.And multi-objective optimization to improve the safety of frontal collision of the vehicle and reduce the quality of the anti-collision beam.First,a brief description of the nonlinear explicit dynamics finite element theory involved in the collision simulation process of the bumper anti-collision beam。 the finite element model of the original benchmarking structure of the bumper anti-collision beam was established.For high-speed and low-speed operating conditions,numerical simulations were carried out using LS-DYNA software.The effectiveness of the model is verified by the comparison results of the simulation and test of the deformation mode of the bumper anti-collision beam under high-speed collision conditions.The maximum intrusion amount of the bumper anti-collision beam,the energy absorption,and the cross-sectional peak force of the front longitudinal beam under the low-speed impact condition of the pendulum collider are extracted as the crashworthiness evaluation index and the crashworthiness design baseline.Then,four types of bumper anti-collision beam structures with different cross-sectional shapes were designed.The four types of bumper anti-collision beams designed were simulated and analyzed by numerical simulation methods,and the best cross-sectional shape of the anti-collision beams was optimized through the comparative analysis of crashworthiness indexes.To fully improve the utilization of materials with different characteristics,reduce the quality of the anti-collision beam and improve the safety of collision resistance,according to the stress distribution results of the anti-collision beam during the collision process,the newly designed anti-collision beam is divided into four structural areas for the next optimization Foundation.Finally,the multi-material variable-thickness multi-objective optimization is carried out for the designed new anti-collision beam.The material and thickness of the structure in each area of the anti-collision beam are used as design variables,and the crashworthiness index and quality are used as the optimal response.The neural network(RBF)approximate model is combined with the NSGA-II intelligent optimization algorithm to perform multi-objective optimization iterations.After optimization,the mass of the anti-collision beam is reduced by 45.45%,the maximum intrusion volume is reduced by 13.64%,the energy absorption is increased by 4.05%,and the peak force of the front longitudinal beam section is reduced by 6.23%,achieving a better lightweight effect.Therefore,the new type of anti-collision beam with multi-material and variable thickness can better realize the weight reduction of automobiles and improve the safety of collision compared with the uniform-thickness anti-collision beam of steel.