
A Multi-Scale Visco-Elastic Modeling Approach Applied to DMA Tests of Multi-Layered Laminates with Thermoplastic Matrix
Please login to view abstract download link
Polymer matrix materials typically show visco-elastic behavior which leads to an overall non-isotropic damping response of a fiber-reinforced composite ply. This effect has not received that much attention until now, but with the increasing use of thermoplastic matrix materials, which show more pronounced damping than thermosets, is becoming more relevant in the design of composite structures. In this presentation, a multi-scale modeling approach for anisotropic visco-elasticity proposed previously [1] is slightly modified to follow the formulation of [2] and applied to DMA tests of a number of multi-layered laminated plates in a 3-point bending configuration. To this end, the material response of the pure thermoplastic matrix is calibrated from the same type of DMA test based on a FEM model of the test setup using the steady state vibration analysis in the software ABAQUS and assuming an isotropic linear visco-elastic response. This matrix response is then used in a hexagonal unit-cell of the UD-material to obtain the anisotropic homogenized response assuming linear elastic fibers. The anisotropic visco-elastic model which uses separate Prony series for all entries of the stiffness matrix is finally applied as a UMAT to the FEM model of the DMA test for various layups. Comparing the modeling results to experimental data of the laminate tests shows qualitatively a good agreement for angle-ply laminates, but less so for a quasi-isotropic layup. One major observation in terms of quantitative results indicates, that the homogenization from the hexagonal unit-cell does not capture the visco-elastic response adequately. Application of the homogenized ply-response to the FEM model, however, shows a reasonably good agreement. [1] Moser, C., Pletz, M. and Schuecker, C., Modelling anisotropic viscoelasticity of fibre-reinforced polymer laminates for general loading conditions. Presentation at the 9th ECCOMAS Thematic Conference on the Mechanical Response of Composites: COMPOSITES 2023, Sicily, Italy, 2023. [2] Pettermann, H. E., Cheyrou, C., and DeSimone, A. 2021. Modeling and simulation of anisotropic linear viscoelasticity. Mechanics of Time-Dependent Materials 25, 4, 679–689.