High frequency modeling methodology of the dynamic properties of fiber-reinforced thermoplastic composite

This article presents a methodology for the high frequency modeling of the dynamic properties of glass fiber-reinforced thermoplastic matrix composite (GFRTP) materials used in automotive applications. Specifically, the homogenized complex modulus of the composite is characterized in a wide frequency range, up to 2000 Hz, using transmissibility functions obtained by seismic excitation. An accurate novel material model is presented together with an efficient one-dimensional numerical procedure based on the Euler-Bernoulli beam theory and two-dimensional Mindlin-Reissner plate theory, where the robustness of the model parameter identification process is validated through the combination of the Nelder-Mead nonlinear optimization and particle swarm optimization (PSO) algorithms. As a result, a new methodology is presented to accurately model the high-frequency dynamic behavior of the GFRTP material from experimental transmissibility functions. While the two\-/dimensional method achieves a more accurate fit to the experimental data, the one-dimensional method delivers a reliable approximation, offering computational efficiency and greater ease of implementation.