Study On Axial Compression Of Foam-filled CFRP Thin-walled Tubes

With the rapid development of new automotive material technologies,the use oflightweight and high-energy-absorbing composite materials in body panels and structural parts is gaining popularity.Among them,Carbon Fiber Reinforced Polymer(CFRP)thin-walled tubes as lightweight energy-absorbing structures can be applied to energy-absorbing parts of automobiles,and have a good impact-buffering energy-absorption effect,which realizes lightweighting of automobiles.It is important to reduce energy consumption.In this paper,the experimental method is mainly used.First,the same batch of carbon fiber reinforced composite laminates was tested on the universal testing machine for tensile,compressive and shearing mechanical properties.The elastic modulus of the material was obtained through experimental data processing.Poisson's ratio and other basic parameters;then,the energy absorption of the thin-walled composite thin-walled pipe with the size of 0°,30°,45°,and 60° is compared;and the chamfer size is the second.In the case of 45° and an outer diameter of 30 mm,the axially compressed energy absorbing properties of three thin-walled tubes having lengths and diameters of 80 mm,100 mm,and 120 mm,respectively,were compared;finally,aluminum was used as the metal foam.Non-metallic rigid polyurethane foams were used to fill composite thin-walled tubes.The energy absorption effects of circular tubes filled with different materials were compared.The finite element simulation of LS-DYNA was used to simulate the axial compression of the tubes.The experimental results show that the thin crushing peak force of the thin-walled pipe with 45° chamfering angle is the smallest,the force-displacement curve of the load is the most stable,and the energy-absorbing property is stable;the smaller the length-diameter ratio,the faster the peak force is.Vice versa;the peak crushing force of the metal foam aluminum-filled thin-walled tube is about 1.2 times that of the unfilled tube,and the force-displacement curve of the load is highly variable and the energy absorption effect is not stable;the rigid polyurethane foam-filled thin-walled tube The crushing peak force differs little from the peak force of the unfilled thin-walled pipe,and the fluctuation of the load force-displacement curve is relatively stable,the total energy absorption is increased by about 11%;considering the foam manufacturing and cost factors,It was initially determined that the energy absorbing composite structure of the metal foam aluminum filled carbon fiber reinforced compositematerial thin wall tube is not suitable,and the non-metal rigid polyurethane foam as the filling material of the composite material circular tube can effectively improve the energy absorption capacity;the force-displacement in the simulation calculation results.Similar to the experiment,the peak force error is between 5% and the crush failure mode is “flowering”,which verifies the accuracy of the simulation results.