Environmental ageing of epoxy-based stereolithography parts. Part 2: effect of absorbed moisture on mechanical properties

摘要

The first part of this paper demonstrated how the quasi-Fickian moisture uptake exhibited byudstereolithography resins could be modelled. This part outlines the effect of moistureudabsorption on the mechanical properties of one of the materials. Fickian and dual-Fickianuddiffusion models, using both analytical and FEA techniques were used to model the moistureuduptake in aged samples. Uniaxial tensile testing of dog-bone samples revealed a decrease inudelastic modulus and yield stress and an increase in strain to failure with increased moistureudcontent. A model has been developed to predict the change in stiffness of aged samples overudtime. The results produced from this model show a good correlation to the experimental dataudand FEA predictions. It is proposed that FEA based coupled stress-diffusion analysis methodsudcan be used to predict the effect of moisture on the mechanical performance of parts made byudSL when used in service.