Research On Crashworthiness Characteristics Of Aluminium Honeycomb Sandwich Structures

Lightweight of vehicle body is an important way to promote the energy-saving and emission-reduction for the automotive industry,which contains of two parts,new materials and novel structures.Serving as typical lightweight structure,aluminium honeycomb sandwiches can be widely employed in vehicle body,due to its advantageous mechanical properties.It is common for the vehicle parts bearing the bending,in-panel compression and impacting load,which means great significance to investigate the crashworthiness characteristics under those loading conditions.Therefore,the crashworthiness characteristics and energy absorbing mechanism of aluminium honeycomb sandwiches were studied,based on both experimental and numerical methods.In addition,the influences of geometric parameters are explored comprehensively.The specific contents can be summarized as follows:Under the bending load,the deformation process and energy absorbing mechanism are revealed by experimental and numerical methods.Based on the experimental and numerical results,a theoretical model for aluminium honeycomb sandwiches under bending load is constructed,which can predict the bending strength,energy absorption and the collapse modes.Under the in-panel compression condition,influences of geometric parameters on the compressing behavior as well as failure modes of aluminium honeycomb sandwiches are studied.The results exhibit that both energy absorption and specific energy absorption are positive with the thickness of cell foil but negative with the thickness of skin.Under the low velocity impacting load,the influences of geometric parameters are investigated by experimental method.Additionally,the critical penetration energy,impacting angle and the impacting mass are explored by the finite element model.It found that deflection of the back skin is positive with the thickness ratio of the front facesheet versus the back facesheet,ignoring a sharping drop between the thickness ratio of 0.5 and 1.As for the peak load,the impacting tendency is similar as an upward para-curve.