Off-the-Shelf Simulation for Demoldable Mandrels: An Experimental and Numerical Approach to Thermoplastic Shape-Memory Polymers

Abstract

The production of one-piece composite hollow profiles with undercuts presents significant challenges to conventional mold concepts. Mandrels made of thermoplastic shape-memory polymers could facilitate demolding and reduce tooling costs. To design molds in a commercial environment, it is critical to determine their behavior using off-the-shelf Finite Element Analysis (FEA) software Ansys 2024R1. This study presents a shape-memory test procedure for coupon test specimens under tensile load. Furthermore, the test is used to validate a simulation using a generalized Maxwell model, a linear viscoelastic material model implemented in off-the-shelf commercial FEA software Ansys 2024R1. The material investigated is amorphous PET. The simulation shows good results in comparison with the thermo-mechanical shape-memory test. The results are then transferred to blow-molded bottle-shaped mandrels, e.g., for the manufacturing of Type V pressure vessels. Test results are compared with the simulation results and deviations are discussed. In conclusion, the straightforward “from material to solution” approach presented allows us to model and simulate the shape-memory behavior of linear viscoelastic polymers with off-the-shelf commercial FEA software.

Authors 4

1. Fabian Flüh corresponding

   Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

   Affiliation as printed

   German Aerospace Center (DLR), Institute of Lightweight Systems, 38108 Braunschweig, Germany

2. Parth Shingte

   Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

   Affiliation as printed

   German Aerospace Center (DLR), Institute of Lightweight Systems, 38108 Braunschweig, Germany

3. Óscar Ludeña Navarro

   Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

   Affiliation as printed

   German Aerospace Center (DLR), Institute of Lightweight Systems, 38108 Braunschweig, Germany

4. Jonas Wermter Aachen Institute for Plastics Processing in Industry and Craft

   RWTH Aachen University

   Affiliation as printed

   Institute for Plastics Processing in Industry and Craft at RWTH, Aachen University (IKV), 52074 Aachen, Germany