Dynamic response and energy absorption properties of epoxy resin composite materials
In order to explore the dynamic response and failure mechanism of hollow glass microsphere/epoxy resin composite materials under impact loads,this study conducted overall impact tests were carried out on the materials using a drop hammer impact testing machine.The damage morphology and impact load-displacement curves of composite materials with different impact velocities and different microsphere contents were obtained.Then the variationsin peak load,energy absorption,specific energy absorption and energy absorption rate were studied.Additionally,the concepts of elastic energy density and dissipated energy density were introduced to analyze the internal energy evolution distribution and damage mechanism of the materials.The results show that the degree of damage,peak load,energy absorption and specific energy absorption of the material have significant strain rate effects.Specifically,when the microsphere content is at 10%,the peak load is 95 kN,the specific energy absorption is 28.21 J/g,the energy absorption rate reaches 90%,and the energy storage limit is 6.46 kJ/m3,showing excellent impact-bearing capacity and energy absorption capacity.According to the energy density curve,the input energy is mainly stored as elastic energy before the stress peak,while the dissipation energy density increases sharply after the stress peak.The impact energy is mainly dissipated through damage mechanisms such as the internal crack sprouting and expansion of the specimen and the damage form of microsphere rupture and debonding.