Improving Damage Tolerance with Energy Absorbing Mesh in Composite Laminates: An Experimental Study

Abstract

This study aims to evaluate the impact resistance of carbon fiber reinforced polymer (CFRP) skin sandwich structures having strain sensitive, energy absorbing D3O® mesh cores. CFRP plates were fabricated having 5, 7, 10 and 14 layers respectively. The 5 and 7 layer plates were used as facing skins for sandwich structures containing D3O® mesh as the cores. Impact energy absorption characteristics were assessed using Charpy tests and 4 J low velocity drop weight tests. Sandwich structures with D3O® cores absorbed more energy compared to the CFRP only samples. Furthermore, the sandwich structures showed lower peak loads, ductile behavior and were able to survive greater impact damage than CFRP only. Post impact thermography was performed on the front and back of impacted samples and compared with the undamaged state. The results revealed that lesser subsurface delamination occurred in the mesh incorporated structures compared to the CFRP only samples after impacting. Thus, the approach increased the impact resistance of the CFRP incorporated mesh structures.