Adhesive strength analysis and real-scale simulation for smart curing in a large turbine blade with carbon fiber-reinforced plastic spar cap

Various approaches for the smart curing processes in the fabrication of large hybrid composite blades have been employed to determine whether smart curing, which has multiple heating and cooling processes during the total curing time, is applicable to the adhesive process between carbon fiber-reinforced plastic (CFRP) and glass fiber-reinforced plastic (GFRP). Therefore, investigating the adhesive strength and residual thermal stress between CFRP and GFRP is very important. In an experimental approach, the adhesive strengths of CFRP/GFRP single-lap joint specimens were compared according to surface treatment techniques and curing conditions. The proper roughness of the CFRP surface and the application of smart curing are very effective for the manufacture of CFRP spar cap wind turbines. The simulation results from the analytical approach demonstrated that when the final curing temperature was reduced by the smart curing process, the residual thermal stress and thermal shear stress in the blade were also reduced, resulting in an increased adhesive strength in the adhesive layers between the CFRP spar caps and GFRP skin. It was determined that large hybrid wind blades with CFRP spar caps could be efficiently manufactured using a smart curing process.