| Lightweight and safety are two primary goals of the collision and energy-absorbing structure in the field of traffic and transportation.How to achieve a high energy absorption capacity of the structure under the condition of low initial peak crushing force is critical for the energy-absorbing structure.In this paper,a new type of collision-resistance energyabsorbing composite structure—metal wire crochet-sintered mesh tube(C)and 6063 thinwalled tube(T)layered composite structure is proposed to study its axial crushing behavior and energy absorption characteristics under static and dynamic loading conditions.In this paper,the crocheted flexible mesh tube are prepared by loop crocheting of short needles in the same direction with 7*7 multistrand ultrafine soft 304 stainless steel wire rope using 0.5mm diameter,and then certain rigid crochet-sintered mesh tube are obtained by vacuum solid-state sintering at 1330°C.The crochetet-sintered mesh tube has various forms of sintering necks,and the pore structure is uniformly and regularly arranged.Axial crushing behavior and energy absorption characteristics of crochet-sintered mesh tube were studied by quasi-static axial compression and drop hammer impact test.The study shows that the crochet-sintered mesh tube has a long energy absorption platform.The length of the platform reaches more than 70% of the total length of the structure,the crushing force efficiency(CFE)is high,and the CFE is over 66%.But because of its weak load capacity,it is not suitable to be used as an independent structure for energy absorption and is an excellent energy absorption structure component.The axial compression behavior and energy absorption characteristics of 6063 aluminum alloy thin-walled tubes are studied by quasi-static axial compression and drop hammer impact test.The experiment shows that the force of 6063 aluminum alloy thin-walled tubes is zigzag,and this tube has good capacity ability,and a certain energy absorption capacity,but the CFE of the structure is far inferior to that of the crochet-sintered mesh tube.It was reduced by 24% compared with the crochet-sintered mesh tube.Therefore,combining the energy absorption advantage of the two,this paper puts forward a composite structure which combines the crochet-sintered mesh tube with the 6063 aluminum alloy thin-walled tube to achieving a more comprehensive excellent energy absorption properties.The crochet-sintered mesh tube(C)and the thin-walled 6063 aluminum alloy tube(T)were formed by interference fit to form four different compound forms of layered composite structure,namely TC(the thin-walled 6063 aluminum alloy tube is inside the crochet-sintering mensh tube),CT(the crochet-sintering mensh tube is inside the thinwalled 6063 aluminum alloy tube),CTC(the thin-walled 6063 aluminum alloy tube is between two crochet-sintering mensh tubes),TCT(the crochet-sintering mensh tube is between two thin-walled 6063 aluminum alloy tubes).The axial energy absorption characteristics of composite structure,crochet-sintering mensh tube and 6063 aluminum alloy thin-walled tube were compared.The effects of composite method on the energy absorption and deformation modes of the composite tube under the interaction of the C tube and the T tube were studied.Studies have shown that the fou r types of composite structures increase the effective energy absorption(EA),mean crushing force(MCF),and the CFE of the structure.Under the quasi-static axial compression,the EA of the four composite structures increased by 8.7%-58.8%,the MCF increased by 19.3%-73.3%,and the CFE increased by 10.51%-23.96%.Among them,the largest increase in EA and MCF is the TCT structure,and the largest increase in CFE is the CTC structure.There are strong interaction effects in the four composite structures.The EA of the composite structure is greater than the sum of the EA by the corresponding single tubes.Under the quasi-static axial compression,the effective energy absorption of the four composite structures is increased by 6.85%-12.04% over the sum of corresponding single tube energy absorption.Among them,the interaction effect of CTC structure is the most significant.The axial impact energy absorption characteristics of the C tube,the T tube and the four composite structures are studied by the drop hammer impact test.The study shows that the composite form will significantly affect the deformation mode and energy absorption capacity of the structure.The MCF and EA of TCT structure is the largest in the four composite structures,and the CFE of CTC structure is the highest.Moreover,the CTC structure has realized the reduction of the initial crushing peak force,the enhancement of the bearing capacity of the structure,the increase of effective energy absorption,It has excellent energy absorption effects.The effect of impact velocity on the structural deformation mode and energy absorption characteristics is discussed.The results show that the CFE of CTC and TCT structures increases with the increase of impact velocity,the higher the CFE,the better the energy absorption effect and the better the anticollision performance,which fully embodies the advantages of the two composite structures in the impact field.Through the static and dynamic experiments mentioned above,the crochetet-sintered mesh tube can enhance the energy absorption characteristics of the 6063 aluminum alloy tube under the condition of low inial peak crushing force.This layered composite tube can provide a new scheme for the optimization of energy absorption structur e in the field of anticollision. |
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