Isogeometric multi-patch analysis for de-bonding and delamination failure propagation

• Applicant: Professor Dr.-Ing. Martin Ruess
• Subject Area: Mechanics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 515687474

Isogeometric analysis has started with the aim to revolutionize the modeling of numerical computations in an industrial context and to bring about a paradigm shift in modeling. The labor-intensive and costly 80/20 mismatch of modeling and simulation was to be eliminated through the direct use of NURBS-based CAD models. Despite intensive and successful research & development that has led to significant improvements in numerical simulation in various disciplines, the implementation of the originally formulated goal is still in its infancy. The goal of this research project is to provide new and significant insights into propagation phenomena in weakly coupled multi-patch NURBS models, thus exploiting the potential of the original paradigm: NURBS-based simulation models in an engineering context. The project goals can be divided into the following three scientific pillars: (i) Investigation of a continuity-preserving coupling model for multi-patch NURBS models considering non-linear material properties. Of particular interest herein are models with many shared coupling edges, for which across the coupling interfaces, perturbation-free continuity in the force profile must be ensured. Treatment of concentrated and degenerate coupling interfaces of many NURBS patches will lead to significant insights into the effects of the model error on coupling conditions. A robust formulation and implementation of the coupling mechanism will significantly promote the acceptance of isogeometric analysis and further strengthen the scientific and economic potential of the method. (ii) Development of a decoupling formulation of cohesive composite structures based on a Nitsche approach to simulate delamination and adhesive failure along the coupling interface. In particular, the unperturbed propagation failure along and across coupling interfaces is in the focus of this scientific pillar. The investigations will reveal insights into the relationship between coupling stiffnesses, stability, and accuracy of the analysis and support a refined stabilization approach. (iii) Development of a model refinement that allows h/p adaptivity based on superposed weakly coupled refinement meshes with acceptable effort and minimally invasive model changes. The refinement follows the propagation front of delamination or adhesive failure independently of element configurations of the base mesh and promises the highest degree of flexibility. All three pillars define work packages that will be developed largely independently and merged into an analysis framework for application to industry-relevant models.

• DFG Programme: Research Grants
• International Connection: Netherlands
• Cooperation Partner: Professor Dr. Sergio Turteltaub