Towards brittle damage in carbon fiber reinforced plastics: A gradient extended approach

• Published in: Composite structures 2021-01, Vol.255, p.112911, Article 112911
• Main Authors: Poggenpohl, Lukas, Brepols, Tim, Holthusen, Hagen, Wulfinghoff, Stephan, Reese, Stefanie
• Format: Article
• Language: English
• Subjects: CFRP; Gradient damage; Material anisotropy; Material modeling
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2020.112911

This work is concerned with material modeling of carbon fiber reinforced plastics (CFRPs) with the prospect of application to shear cutting. It is assumed that the use of CFRPs for body parts is of great benefit in the field of lightweight construction. The presented material model distinguishes between damage in the isotropic and anisotropic part. It represents a special case of a more general thermodynamical framework. Furthermore, the micromorphic approach is used to overcome undesired mesh dependencies. A mesh convergence study is performed and the resultant force displacement curves are analyzed quantitatively. Tension tests are performed and the material model is fitted as well as tested on this data. The experimental data is used to justify the choice of the material model. Novelty of this work lies in an comparison of the crack paths of experiments and simulations. A direction dependence is included in the gradient term of the micromorphic extension to obtain the same crack paths in simulation and experiments.