Speaker
Description
Damping elements made of elastomers are often used in dynamic systems such as vehicles or centrifuges. Numerical simulation methods in general and multi-body simulation (MBS) in particular are applied to predict loads and kinematic quantities in these technical systems. This requires knowledge of mass, damping and stiffness properties. Therefore, the modeling of elastomer components is essential for high prediction accuracy. However, the complex and extremely non-linear material behavior of elastomers requires material models capable of reproducing these mechanical properties. Various phenomenological or physically-based approaches exist. The latter offer the advantage that the few material parameters are valid independent from the load conditions, hence, experimental effort for material characterization is limited. The dynamic flocculation model (DFM) by Lorenz \& Klüppel [1,2] is such a physically-motivated model, which reproduces the material response of filled elastomers in one dimension. For a more realistic modeling of elastomer components, a three-dimensional formulation is required, which is implemented for finite element analyses (FEA). For this purpose, Freund [3,4] proposed a generalization method from 1D to 3D by establishing the concept of representative directions (CRD). This is based on a finite number of directions, approximately equally distributed in space, for which the corresponding one-dimensional material response is calculated and integrated over all directions. In conclusion, an efficient coupling to FEA is necessary to integrate the DFM into MBS. Consequently, the computation time of the FE implementation of the material model should be minimized. This is a contradiction to the CRD, so this contribution investigates on strategies to improve the efficiency of the CRD applied to the DFM. These include a method to reduce the number of directions and an approach to minimize the memory requirements for a constant number of directions.
References
[1] Lorenz, H., Klüppel, M.: A microstructure-based model of the stress–strain behavior of filled elastomers. In: Heinrich, G. et al. (Eds.), Constitutive Models for Rubber VI, pp. 423-428 (2009)
[2] Raghunath, R.: A new physically motivated thermoviscoelastic model for filled elastomers. PhD thesis, OvGU Magdeburg (2017)
[3] Freund, M. et al.: Finite element implementation of a microstructure-based model for filled elastomers. International Journal of Plasticity 27, pp. 902-919 (2011)
[4] Freund, M. : Verallgemeinerung eindimensionaler Materialmodelle für die Finite-Elemente-Methode. PhD thesis, TU Chemnitz (2012)
