Infrared laser heating of GFRP bars and finite element temperature field simulation

Glass fiber-reinforced polymer (GFRP) composites were prepared with ortho-phthalic unsaturated polyester resin as the matrix. Mass productions were carried out on a production line using infrared laser radiation and tunnel-kiln heating. Infrared laser radiation heating can realize internal and external collaborative curing by utilizing the deep penetration of the infrared laser, whereas, the curing of tunnel kilns mainly depends on heat conduction and heat convection. The tensile strength of the bar cured by laser radiation was approximately 25% higher than that of the bar cured by the tunnel kiln. The temperature field of the GFRP bars under the two curing modes was simulated using the finite element method, and The fiber at the fracture of reinforcement was analyzed using scanning electron microscopy and FTIR spectrum. The results showed that there was more fiber adhesion resin in the GFRP bars heated by infrared laser radiation, whereas the adhesion resin on the fibers was less scattered in the tunnel–kiln-heated GFRP bars.