This paper presents results of material characterisation experiments on the hygrothermal viscoelastic behaviour of unidirectional laminates of continuous carbon-fibre reinforced polyamide 6. The material behaviour when subjected to the automotive painting process is of interest.Coefficients of thermal-and -moisture expansion were determined from dilatometer experiments and micrometer measurements together with weighing, respectively. Diffusion coefficients were generated from thermogravimetric analysis and fitted with the Arrhenius equation. Dynamic mechanical analysis and digital image correlation of quasi-static tensile tests were performed to obtain a relaxation curve and a major Poisson's ratio, respectively. The Williams-Landel-Ferry equation was fitted to the time shift factors.

Thermoplastics are favourable to the automotive industry due to their recycling possibility. Carbon fiber reinforced thermoplastics (CFRTP) are passed through the automotive paint shop. The imposed thermal loading presents a challenge to implementing economically feasible CFRTP in body structures. The present study provides a simulation approach to analyse the anisotropic viscoelastic deformation behaviour to assess this scenario. Validation experiments were conducted by optically measuring the out-of-plane displacement of dry and moisture-saturated specimens subjected to a simulated cathodic dip painting-dryer. Preliminary lay-up assessment for the automotive painting process is deemed possible due to the good agreement between simulation and experiments.