Surface waviness of continuous fiber-reinforced thermosets - Experimental and numerical studies considering the viscoelasticity of the resin

This contribution aims to understand surface waviness formation during cooling and post-curing of glass fiberreinforced plastics (GFRP). GFRP plates were manufactured by resin transfer molding (RTM). Part surface waviness is determined by tactile contour measuring at ambient temperature up to 1008 h after initial cooling. Additionally, the manufactured plates were exposed to elevated post-curing temperatures to study the influence of resins' viscoelasticity on their surface waviness. In parallel, the curing and post-curing processes were analyzed using a cure- and temperature-dependent viscoelastic simulation model. The experimental results of this work capture the influence of the resin's viscoelastic behavior on the surface waviness at ambient and temperatures. The numerical results show a satisfactory agreement with experimental values. Surface waviness amplitude increases up to 25 % for the applied post-curing cycle. The results of the present work underline the importance of the resin's temperature-dependent viscoelasticity on the process-related formation of surface waviness.

Automated summary

This study aims to understand the formation of surface waviness during cooling and post-curing of GFRP. Experimental and numerical results show that the viscoelastic behavior of the resin plays a crucial role in the formation of surface waviness.