Study On Crashworthiness Of Porous Cellular Materials Filled Composite Structures

The rapid growth of automobile ownership has brought us great convenience,and it has also led to frequent traffic accidents,serious environmental pollution and energy shortages.In order to protect the safety of occupants in the event of a traffic accident and effectively reduce environmental pollution and energy consumption,the crashworthiness and lightweight design of the vehicle energy absorbing device have always been a research hotspot of automobile safety.Aiming at the defects of low energy absorption efficiency and poor load stability of traditional metal single-walled structures,this paper proposes the design method of compound filling of porous cellular material and fiber-reinforced porous cellular material,and studies its energy absorption by means of finite element numerical analysis and experimental test.The specific contents are as follows:(1)A composite filling structure based on foam and honeycomb porous materials was proposed,and the effects of single material partial filling,full filling and different materials composite filling designs on the crashworthiness performance of the structure were compared.The study found that the composite filling design of honeycomb and foam can improve the energy absorption capacity of circular multi-wall structure,and its crashworthiness is better than that of single material filling structure;In addition,for a single cellular filled structure,the crashworthiness of partially filled structure is better than that of fully filled structure.Therefore,the use of a porous cellular material for the energy absorbing component can be considered in the form of a partially filled design.(2)Exploring the mechanical properties of the porous cellular materials based on carbon fiber composite reinforcement,and experimentally studying the energy absorption mechanism of the fiber-reinforced porous cellular materials and its filling structures under different parameters.It is found that the number,diameter of carbon fiber reinforced tubes and the density of the polyurethane foam in the fiber-reinforced porous cellular material have a greater influence on the crashworthiness,while the distribution radius of the carbon fiber reinforced tube has less influence;In addition,the interaction between the fiber thin-walled tube and the porous cellular material can better enhance the energy absorption of the fiber-reinforced cell material;In addition,experiments were carried out to comparative analyze the crashworthiness of fiberreinforced porous cellular materials and conventional porous materials(aluminum foam and aluminum honeycomb)filled structures,and it is found that the fiberreinforced cellular material filling structure proposed in this paper has better crashworthiness than aluminum honeycomb and aluminum foam filling structures.Therefore,the design of the fiber-reinforced porous cellular materials provides a new idea for improving the energy absorption of the structure.