Thermo Vacuum Forming process: Simulation and Validation

During the forming of the product in the thermo-vacuum forming process, a heated thermoplastic sheet is subjected to a complex and dynamic multi-axial deformation. In order to measure the mechanical response of the material during processing, an experimental method that applies the relevant modes of deformation during forming is required. The bubble inflation technique combined with digital image correlation (DIC) gives valuable data including principal stresses and strains as well as the local thickness at the specimen pole. This data is used to calibrate the nonlinear term of the constitutive material model. The final goal of this approach is to apply the calibrated material model in a thermoforming process simulation tool.