Finite Element Analysis Of Impact Characteristics Of GFRP And Aluminum Alloy Thin-walled Tubes With Induced Imperfection

Because the thin-walled tube subjected to axial impact is the same as the energy absorption mechanism when the car is subjected to a frontal collision,and with the wide application of the composite material,the GFRP thin-walled tube with buffer energy absorption performance has also been more and more Pay attention to it.In order to reduce the damage caused by the collision,it is critical to use energy-absorbing load-bearing structures to absorb energy in their deformation.Therefore,it is particularly important to study the buffer energy absorption characteristics of composite materials and thin metal wall structures.The finite element method is used to simulate the impact resistance of GFRP thin-walled tubes under axial impact load.The displacement,velocity,acceleration response and thin wall at the midpoint of the upper end face of GFRP thin-walled tubes are analyzed.The influence of the cross-sectional shape and wall thickness of the tube on its deformation mode,impact resistance and energy absorption capacity.After comparing with the experimental results,it is found that the two agree well in the force-deformation curve,the energy absorption and the specific energy absorption.By analyzing the stress-strain curves and force-displacement curves of thin-walled glass fiber reinforced plastic tubes with different wall thicknesses,the results show that the impact resistance of the round tube is better than that of the square tube.Increasing the wall thickness helps to improve the energy absorption of thin-walled tubes.The finite element method is used to study the aluminum alloy thin-walled tubes with different cross-sections but the same circumference under axial impact loading conditions,and the reliability of the finite element model is verified.Based on the reliable finite element model,the energy absorption characteristics of polygonal aluminum alloy thin-walled tubes with different cross-sections were studied.The influence of the geometric parameters of the thin-walled aluminum alloy tubes with induced defects on the energy absorption characteristics was analyzed.The results show that the length and width of the induced pores have a significant influence on the energy absorption characteristics.Reasonable selection of various factors can effectively improve the energy absorption characteristics.In order to find the thin-walled tube with induced imperfection,the mature experimental design theory and response surface method were used to optimize the induced hole.The Pareto frontier solution obtained by the genetic algorithm toolbox is used to find the optimal solution,so that the designer can better determine the optimal design variables according to the optimization problem.Through the finite element analysis of the tapered segmental aluminum alloy thin-walled tube under axial load,the parameters of energy absorption,initial peak force,compression force efficiency and specific energy absorption are obtained.The influence of cone angle and number of segments on the energy absorption characteristics of tapered thin-walled tubes is analyzed.The results show that the initial peak force and specific energy absorption of the tapered segmented tube are improved compared to the simple tapered tube.