Structure Optimization Of Automobile Energy Absorber Block Based On Rapid Prototyping Technology

For most car traffic accidents in low-speed collisions,people use energy-absorbing boxes to reduce the damage to people and property caused by low-speed collisions.The traditional thin-wall stamping type automobile energy-absorbing box has a relatively high rigidity,and the energy absorption effect is poor when collapsing,and the vibration generated when the collision occurs cannot be greatly weakened.In order to solve this problem,this topic uses rapid prototyping technology to study and design thin-walled parts with lightweight multi-cell structure to improve the energy absorption effect of the energy-absorbing box.The thesis carries out research work from the following aspects:At the beginning of the article,a lattice array hollow cell structure was designed using topology optimization techniques based on the working conditions of the part and the characteristics of rapid prototyping.Through the control variable method,the dif-ference in performance of various structures in the case of uniform mass,uniform cell size,and different cell wall thicknesses was investigated.The mathematical structure is used to quantify the size,wall thickness and mass relationship of the test piece structure,and the test piece is three-dimensionally modeled using the calculated data.(1)According to the structural characteristics of the unit cell,three typical unit cell units are selected,and a lattice array hollow cell structure is designed using topology optimization techniques under the constraints of the part operating conditions.Under the conditions of the same material quality and unit cell size,the digital design parameters of the unit cell structure were analyzed.The relationship between the size,wall thickness and mass relationship of the multi-cell specimens was quantified,and the calculations were calculated according to the design constraints.Design parameters were used to establish three-dimensional modeling of the test piece.Considering the effects of cost and use environment,it is determined that the test piece is processed by photocuring using a photosensitive resin as a substrate.(2)In order to obtain the structural performance of the unit cell,the subj ect has carried out simulation analysis on the compression performance of the poly unit cell structure.However,there may be differences in material properties between the rapid prototyping and the conventional molding.In order to obtain the performance parameters required for the simulation.the material properties of the rapidly formed test pieces were first studied using tensile and compression experiments before the simulation.The structural strength analysis of the designed poly unit cell structure was carried out using the obtained performance parameters.The results show that the hexagonal unit cell has the largest structural bearing capacity,and the smallest is the lattice hollow cell unit.(3)Due to the technical limitations of the finite element simulation software,physical compression experiments are also required to obtain real structural performance.According to the compression experiment,the load,time and displacement data of different lattice structures under pressure were obtained.The results show that the four polycrystalline cell specimens are drum-deformed when pressed,the maximum strength structure is hexagonal lattice structure,and the smallest structure is lattice hollow lattice structure.Combined with the results of finite element simulation analysis,the correctness of the deformation results is verified.(4)In order to realize the gradient energy absorption characteristics of the new car energy absorbing box,this paper designed a multi-cell composite structure.Firstly,the energy absorption effect of the composite structure under static compression mode was studied by simulation analysis and solid crushing experiment.The structure was subjected to a drop-impact impact test to study the energy absorption reaction rate and energy absorption ratio in the high-speed collapse mode.The results show that the new energy absorbing box structure can perform gradient deformation energy absorption,high crushing response,high energy absorption ratio,and mechanical strength superior to the traditional energy absorbing box strength.