Determination of Constitutive Parameters From 3D Strain Fields

Fibre-reinforced polymer composites combine a stiff and strong reinforcing fibre with a relatively compliant matrix to bind the fibres together. They are taking up a central role in lightweight solutions, as they combine a high stiffness and strength with a low density. Apart from the fibre and matrix, the fibre/matrix interface is often considered to be the third constituent. These three constituents govern the mechanical performance of composites and knowing their constitutive parameters is crucial for predictive micromechanical models. Motivated by recent advancements in digital volume correlation performed on in-situ synchro­tron measurements [1], we present an approach to determine these parameters from strain fields. We leverage a fast FFT-based solver implemented in DAMASK [2] that operates on a regular grid which enables a direct takeover of experimental data. To evaluate the capabilities and limits of the approach, a sensitivity study is performed in combination with a systematic parameter study.

References

1. T. Chatziathanasiou, S. E. Madi, T. Sinha, J. Soete, M. Diehl, C. Breite, M. Mehdikhani, and Y. Swolfs, Strain mapping around fibre breaks in single- and multi-fibre composites: quantifying microscale deformation and damage via digital volume correlation, Composites Part B: Engineering, 316:113581, https://doi.org/10.1016/j.compositesb.2026.113581.
2. F. Roters, M. Diehl, P. Shanthraj, P. Eisenlohr, C. Reuber, S. L. Wong, T. Maiti, A. Ebrahimi, T. Hochrainer, H.-O. Fabritius, S. Nikolov, M. Friak, N. Fujita, N. Grilli, K. G. F. Janssens, N. Jia, P. J. J. Kok, D. Ma, F. Meier, E. Werner, M. Stricker, D. Weygand, and D. Raabe, Damask – the düsseldorf advanced material simulation kit for modelling multi-physics crystal plasticity, damage, and thermal phenomena from the single crystal up to the component scale, Computational Materials Science, 158:420–478, https://doi.org/10.1016/j.commatsci.2018.04.030.