Geometrical optimization of thermoforming continuous fibers reinforced thermoplastics with Finite Element Models: A case study

The manufacturing of thermoformed components of continuous fiber-reinforced thermoplastics (CFRTPs) relies on an optimization process owing to a demand for quality and the mechanical requirements. Geometrical optimization is typically based on trial-and-error processes, and delays due to the manufacturing of different prototypes increases the development cost of the final product. In this study, the mechanical behavior of a CFRTPs top mount damping component made of polyamide 6 (PA6) reinforced with long glass fibers (47% in volume) and installed in an automobile differential system was evaluated. This was achieved by developing ad hoc tooling for axial testing. The experimental results were used to validate those obtained using a finite element (FE) model based on the fabricated geometry and mechanical properties of the CFRTPs laminate. Furthermore, a complete mathematical procedure was implemented to address the lack of information on the mechanical moduli and Poisson's ratio in the material datasheet for the FE simulation. This method was based on a Halpin-Tsai model and classical lamination theory with a 3D expansion for out-of-plane mechanical property calculation, wherein Tsai's modulus was obtained for checking purposes. The obtained results were fitted with the test results to validate the developed FE model. In addition, this model was used to further optimize the component geometry. The implementation of in silico models based on FE techniques can be useful for accelerating the development of recyclable CFRTPs for large-scale production, allowing significant weight reduction and lower greenhouse emission without diminishing their reliability and safety throughout their useful life.