Research On Low-velocity Impact Performance Of Steel Trapezoidal Corrugated(Hybrid) Sandwich Panels

Sandwich structures are widely used in aerospace,automobile,shipbuilding and other fields due to their light weight,high strength and good characteristics of energy absorption.The research on sandwich structure mechanical behaviors and response characteristics under low-velocity impact load is the basis of an accurate assessment of its crashworthiness,which is of great significance.The main research work and conclusions are as follows:(1)As to three different kinds of impact energy,three different kinds of impactor diameter,two different kinds of impact position and three different kinds of panel thickness,investigations of eight cases on the steel trapezoidal corrugated sandwich panels were conducted using the drop hammer apparatus.Based on the FEM code ANSYS/LS-DYNA,numerical simulation investigations were carried out.It turned out that the numerical results were in good agreement with the experimental results.The influence of five different kinds of impact angle on the crashworthiness of sandwich panel was further investigated.The results show that the impact energy and panel thickness have a great influence on the response characteristics of sandwich panel,but the impactor diameter has little influence on them.As to five different kinds of impact angle,the sandwich panel deformation and impact force are biggest when the sandwich panel is vertically impacted.(2)As to three different kinds of aluminum foam filler density,two different kinds of filling method,four different kinds of filler density combination and three different kinds of panel thickness,investigations of eleven cases on the steel trapezoidal corrugated aluminum foam hybrid sandwich panels were conducted using the drop hammer apparatus.The numerical results based on the FEM code ANSYS/LS-DYNA agreed well with the experimental results.The results show that taking the plastic deformation of the bottom panel as the criterion to evaluate the crashworthiness,filling with low density aluminum foam,using the “middle density aluminum foam up-filling + low density aluminum foam down-filling” method and using the “middle density aluminum foam up-filling” method all can improve the crashworthiness of sandwich panel when compared with steel trapezoidal corrugated sandwich panel without aluminum foam filled.(3)As to nine different kinds of preformed induced defect,investigations of nine cases on the steel trapezoidal corrugated sandwich panels with induced defects were conducted using the drop hammer apparatus.As to three different kinds of hole and two different kinds of aluminum foam filler density,investigations of six cases on the steel trapezoidal corrugated aluminum foam hybrid sandwich panels with induced defects were conducted using the drop hammer apparatus.The results show that the introduction of the induced defects increases the deformation of the sandwich panel but decreases the impact load when compared with the steel trapezoidal corrugated(hybrid)sandwich panel without induced defects.The research work in this paper provides a useful reference for corrugated sandwich structures’ application in engineering.