Research On Compression Performance Of Composite Sandwich Structures With S-Shaped Reinforced Aluminum Honeycomb

Carbon fiber reinforced polymer（CFRP）has the advantages of high specific strength,high specific stiffness and high designability,and is an important material for manufacturing thin-walled energy-absorbing components.The traditional CFRP thin-walled energy-absorbing structure is prone to the disadvantages of high maximum peak force,low efficiency of crushing force and unstable crushing process in the axial compression process.The filling of honeycomb material in the CFRP energy-absorbing structure is one of the important means to improve the compression performance of the structure.In this study,compression properties of composite honeycomb sandwich panel and tube structures with S-shaped reinforced core was studied.The main work was as follows:Firstly,the S-shaped structure design was that honeycomb cores for carbon-fiber and aluminum-honeycomb sandwich specimens were restructured by forming in-situ periodic tight zones by flattening hexagon-shaped cells of the aluminum honeycomb.the compression properties of the carbon fiber/S-shaped reinforced aluminum honeycomb sandwich panel and carbon fiber/aluminum honeycomb sandwich panel were first investigated separately using in-plane compression experiments.Quasi-static compression tests showed that the peak force and energy absorption of the proposed sandwich panels were enhanced by up to 85.28%and 31.41%respectively,in comparison to the carbon fiber/aluminum honeycomb sandwich panels.After that,the finite element simulation models of two carbon fiber/aluminum honeycomb sandwich panels were calculated,and the obtained calculation results and damage modes were in good agreement with the experimental results.Secondly,based on the experimentally validated finite element simulation model,the effects of trigger angle,number of plies and layup angle of carbon fiber on the carbon fiber/aluminum honeycomb sandwich tube were investigated.Among them,the trigger angle had a large effect on the maximum peak force of the composite honeycomb sandwich tube;the number of layups showed a linear relationship with the maximum peak force and the energy absorption of the sandwich tube;the layup angle had the greatest effect on the compression properties of the composite honeycomb sandwich tube,and the sandwich tube with the layup angle of[±45/0]₂ had excellent energy absorption characteristics.Then,the effects of number of S-shaped reinforcement structures,wall thickness and rotation direction were investigated for mechanical performance of the carbon fiber/aluminum honeycomb sandwich tubes under compression.The peak force and energy absorption of the sandwich tubes showed quasi-linear relation to the number of S-shaped reinforcement structures and wall thickness.The mechanical behavior and properties of the honeycomb core with S-shaped reinforcement were significantly influenced by changing the distribution of S-shaped reinforcements with different rotating directions.The homodromous structure caused shear damage,while the heterodromous structure showed more stability.Finally,the specific energy absorption and specific peak force of carbon fiber/S-shaped reinforced aluminum honeycomb sandwich tube with different structural parameters were analyzed to illustrate the efficiency of different structures by comparing the incremental specific energy absorption with the incremental specific maximum peak force.The results show that the N10-T0.24-L5R5 carbon fiber/S-shaped reinforced aluminum honeycomb sandwich tube is an excellent energy-absorbing structure.It is a reference for the study of anti-crawl energy absorbers.