Two-scale concurrent simulations for crack propagation using FEM-DEM bridging coupling.

Area of Science:

• Computational mechanics
• Materials science
• Numerical modeling

Background:

• Discrete Element Method (DEM) is effective for granular material simulation but computationally expensive for large domains.
• Finite Element Method (FEM) is efficient for small deformations but less suitable for complex granular behavior.
• Coupling DEM and FEM offers a potential solution to balance accuracy and computational efficiency.

Purpose of the Study:

• To evaluate the accuracy of a strong FEM-DEM coupling formulation for simulating material failure events.
• To assess the impact of DEM domain size on the accuracy of the coupled approach.
• To validate the FEM-DEM coupling against pure DEM simulations for crack propagation and wear.

Main Methods:

• A strong coupling formulation was implemented, linking DEM particles to FEM nodal interpolations in an overlapping region.
• Simulations were performed for mode I crack propagation and shearing of rough surfaces leading to debris.
• The accuracy of the coupled method was assessed by varying the size of the DEM domain and comparing results to pure DEM simulations.

Main Results:

• The FEM-DEM coupling accurately captures material failure, including crack propagation and debris creation.
• The accuracy of the coupled approach is maintained irrespective of the DEM domain size relative to the failure region.
• Computational efficiency is significantly improved compared to pure DEM for large-scale simulations.

Conclusions:

• The strong FEM-DEM coupling is an effective and accurate method for simulating material failure in granular materials.
• This hybrid approach offers a computationally efficient alternative to pure DEM for large-scale engineering problems.
• The validated coupling method can be reliably applied to complex scenarios involving fracture and wear.