Research Of Damage Characteristics Of Carbon Fiber Reinforced Epoxy Resin By Millisecond/Nanosecond Laser

Composite material is a new type of material with complex structure.In recent years,the composites have been widely used in aerospace,space vehicles and automobiles as a substitute for traditional metal materials with rapid development because of their high specific stiffness and specific strength.And the carbon fiber reinforced epoxy resin composite is the most widely used.Anti-ablation performance is one of its important properties,so it has profound value of research and application to research on the ablative mechanism and its action process.Carbon fiber reinforced epoxy composites consist of two completely different materials,in which the matrix epoxy resin is an organic macromolecule compound.During the interaction between the laser and carbon fiber reinforced epoxy resin composites,the ablation performance of the composites is related to the laser characteristics.Therefore,it is of great theoretical and practical significance to study the different damage properties of the carbon fiber reinforced epoxy resin material under different incident conditions.This article focuses on the damage characteristics of millisecond/nanosecond pulsed laser induced carbon fiber reinforced epoxy resin.In terms of theoretical simulations,the theoretical models for the irradiation of carbon fiber reinforced epoxy resin composite with millisecond/nanosecond pulses were established.Based on the theory of heat conduction and thermal elastic-plastic theory,a three-dimensional simulation model of pulsed laser and carbon fiber reinforced epoxy resin was established.In the numerical simulation by use of finite element analysis software,the radial temperature change,and the radial and hoop stress were analyzed in the condition of the pulse widths of 2ms and 10 ns,and the energy density of 8.6J/cm2,20.5J/cm2,and 35.7J/cm2.Finally,the temperature field of the composite material and the variation of the stress field with energy density were achieved.In experimental research,a carbon fiber reinforced epoxy resin damage test system under the irradiation of millisecond/nanosecond pulse laser was built.The temperature of the center point of the material surface was measured by a point temperature meter,and the damage morphology was measured by a full-automatic zoom measurement technique.Then,the plasma expansion distance and the expansion speed during the damage process were measured by the shadow method.Through theoretical analysis and experimental results,the impact of the millisecond/nanosecond pulse width laser on the damage characteristics of carbon fiber reinforced epoxy resin was compared,and the difference in damage characteristics was analyzed.Furthermore,It reveals the damage mechanism of carbon fiber reinforced epoxy resin composites with different pulse width lasers.