Numerical Simulation Of Laser Cutting Process Of Single-layer Carbon Fiber Reinforced Plastics

Carbon Fiber Reinforced Plastics(CFRP)is a advanced material,which combined by carbon fiber as reinforcement and resin as matrix.It has superior properties of both materials.CFRP has high specific stress,good fatigue resistance and designability,which make it wildly used in aerospace,auto industry,wind power generation and sports equipments.Laser cutting is considered as a efficient and high quality CFRP processing method and possesses a broad developing prospect,according to its efficiency,narrow kerf width and no cutting force.As carbon fiber and resin shows different properties in CFRP,it is known as a typical anisotropy material.Process of Laser cutting CFRP is complicated and very different from isotropy materials.With single-layer CFRP as the object of the research,this paper built fiber-spot diameter ratio 3D model,resin-fiber double phase 3D model,single-layer 3D model considering typical fiber orientation and content of resin.Present a numerical simulation of laser cutting single-layer CFRP process scanning parallel and unparallel to the fiber orientation.The main contents and results are as follows:(1)Considering the carbon fiber and laser spot diameter ratio when cutting single-layer CFRP using small spot laser,single-fiber arrangement 3D FE model of fiber-spot ratio 1:1,1:2,1:5 and 1:10 have been established.When laser cutting parallel to the fiber orientation,the temperature field,thermal gradient of the cross section have been analysed.With the declination of fiber-spot ratio,the width of heat affected zone(HAZ)decrease,while the highest temprature and thermal gradient increase.When cutting single-layer CFRP using small spot laser,k<1:10,CFRP can be considered as homogeneous material.To refine single-fiber arrangement model,resin-fiber double phase 3D model has been established.By analysing the temperature field of covered resin and inside fiber,and the cross section temperature curve,energy transmission of the material has been studied,the mechanism of HAZ formation on the surface has been revealed.(2)Experiment of laser cutting single-layer CFRP parallel to fiber orientation has been conducted.According to the fiber-spot ratio in numerical simulation,match the data of the fiber burned on surface width and the HAZ width,the matching curve tend to be stable.When it comes to fiber-spot ratio in the experiment,the error of fiber burned on surface width is 3.37%,the error of HAZ width is 1.92%.(3)Considering typical fiber orientation and resin content,establish single-layer CFRP 3D model respectively.By the temperature field while and after laser cutting unparallel to the fiber orientation,analyse the influence to the shape and the width of HAZ caused by fiber orientation.Temperature transmit along the fiber orientation when stable cutting or without heat source,the temperature transmit in the front of laser also depends on the cutting direction.The temperature field width of 50% resin content declines by 17.24% compared to 30% resin content,with the increase of resin content,the highest temperature increases,the width of temperature field and the highest temperature obey approximate linear variation.(4)Experiment of laser cutting single-layer CFRP unparallel to fiber orientation has been conducted.Compared with the experiment,the simulation data average error of fiber burned on surface width and HAZ width are 10.66% and 13.09%,respectively.