Numerical study of the viscoelastic mechanical response of polystyrene in the process of thermoforming through the generalized Maxwell model

Polystyrene is thermoformed in a viscous state at temperatures corresponding to its crystalline melting point (100-140 degrees C). The mechanical properties of the material change with temperature since these plastics behave viscously when temperature is increased. Findings are presented during numerical simulations, implementing a viscoelastic characterization of laminated polystyrene. A viscoelastic generalized Maxwell model with Prony series is used in the simulation to replicate the thermoforming processes. The results were verified by comparing them through experimental tensile tests at different temperatures. The good agreement between the model and experimentation allows the proper selection of operating parameters such as pressure, time and temperature of the process. (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Advances in Mechanical Engineering Trends. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).