Research On Crashworthiness Of Aluminum Foam Filled Thin-Walled Structures

The passive safety of automobiles depends largely on the crashworthiness of the car body structure.Increasing the crash safety of the car structure is of great significance for reducing the hazards of traffic accidents and ensuring the personal safety of the occupants.Aluminum foam is a porous material with special geometry,which has excellent energy absorption characteristics,and has low density and light weight.It is an ideal collision energy absorbing material for automobiles.In this paper,the multi-level research on the crashworthiness of foam-filled thin-walled structures and their application in automotive structures is carried out.The main research contents are as follows:The deformation mode and energy absorption characteristics of hollow square tube and foam-filled square tube under quasi-static uniaxial compression and axial impact loading are studied.By analyzing the load-displacement curve of the aluminum foam filled square tube,the energy absorption characteristics evaluation indexes such as energy absorption(EA),specific energy absorption(SEA),peak crushing force(PCF),mean crushing force(MCF)and crash load efficiency(CLE)are obtained.The deformation modes and mechanical properties of hollow square tube and foam-filled square tube under three-point bending conditions of quasi-static and impact load were studied.The difference in bending resistance between the hollow square tube and the foam-filled square tube was compared by the finite element simulation analysis method.By analyzing the load-displacement curve,the relevant energy absorption characteristics evaluation indexes such as energy absorption,specific energy absorption,peak crushing force,mean crushing force and crash load efficiency are obtained.Taking the front sill structure of a certain type of SUV as the research object,aluminum foam was filled as energy absorbing material into the inside of the front sill,and the foam-filled front sill structure was designed.Based on the frontal collision conditions of automobile,the dynamic axial crushing performance of the prototype front sill and the foam-filled front sill structure were simulated and analyzed,and the deformation modes and energy absorption characteristics of the two were compared.Taking the B-pillar structure of a certain type of SUV as the research object,the aluminum foam material was filled into the B-pillar structure,and the foam-filled automobile B-pillar structure was designed.Based on the lateral collision conditions of automobile,the dynamic three-point bending performance of the prototype B-pillar structure and the foam-filled B-pillar structure was simulated and analyzed,and the deformation modes and energy absorption characteristics of the two were compared.The research results show that the aluminum foam can be used as an energy absorbing material to fill in the energy absorbing structures of automobile,which can effectively improve the crashworthiness of the structures.The foam-filled energy absorbing composite structure is of great value for improving the collision safety of automobiles.