Simulation And Experimental Study On Low-speed Collision Performance Of Passenger Car Front Bumper

The front bumper of the passenger car is easily damaged byin low-speed collisions and rub accidents in crowed roads,which puts higher demands on the mechanical properties of the car bumpers.Automobile manufacturers have invested in the research and the development of bumper increasingly,especially automotive accessories suppliersexterior parts manufacturers.The impact resistances of the bumper during collision processes have also been continuously studied and explored by experts and scholars at home and abroad.Therefore,to study the dynamic characteristics and the energy absorption characteristics of the front bumper during collision processes is very significantly important.After summarized and analyzed research methods and development status of lowspeed collision performance of automobile bumper,based on which determined the simulation and bench test scheme according to China’s national standard "GB 17354-1998 the evaluation standard of front and rear car protection devices".Hypermesh software was used to extract the middle surfaces from the CAD model of bumper.After clean geometric errors and complete the finite element grid division.the The assembly of model was completed in Abaqus software,and defined the section properties of the finite element model,set the connection relation,selected the contact relation and the contact algorithm the boundary conditions as well as set the hourglass control methods..,The boundary conditions of low-speedThe collision model which included the front bumper assembly,the energy-absorbing foam,the anti-collision beam,the test platform,the trolley and the pendulum was established according to the simulation scheme.Simulated the The frontal collision and corner collision(30°)of the front bumper system were simulated with impact speed of 4km/h and 2.5km/h respectively.According to the simulation results,the collision deformations,stress distributions,collision contact forces and energy absorption characteristics of bumper under lowspeed collision were analyzed in detail.The results show that these indicators are in line with the actual situation,which verified the correctness of the model.The bench test was carried out according to the experimental scheme,the acceleration data of the pendulum and the trolley during the collision and were measured,and speed data and collision contact force were obtained respectively.After comparing the test results and with the simulation results and analyzing the reasons for the differences,it drew a conclusion that the finite element method could simulate the bench test accurately.The trends and numerical results of accelerations,velocities and collision contact forces in the collision test are basically consistent to the bench test results.The But the bench test results of corner collision and the simulation result are quite different due to the large vibration of the trolley.By using the simulation test as the tool and the bench test as the verification means,the low-speed collision mechanics properties of passenger car bumper was obtained,which provides the data support and research ideas for the bumper optimization and design.