A 2D adaptive finite-discrete element method for simulating fracture and fragmentation in geomaterials

• DOI: 10.1016/j.ijrmms.2023.105439
• Publication Date: 2023-06-07T12:26:50Z
• Authors: Chengzeng Yan; Yuchen Zheng; Gang Wang
• Keywords: Uniaxial compression; SHPB-Based dynamic brazilian disc; Dynamically insert cohesive elements; Brazilian disc; 0211 other engineering and technologies; 02 engineering and technology; FDEM; 620

This study proposes a new two-dimensional finite-discrete element method (FDEM) using dynamically inserted cohesive elements. Unlike the conventional FDEM, which sets up cohesive elements between adjacent solid elements to simulate fracture and fragmentation in the geomaterials, the new FDEM adaptively inserts the cohesive elements when the stress exceeds a critical value. The new method is consistent with the conventional FDEM except that it uses a post-peak constitutive model for cohesive elements and a new nodal updating scheme. The accuracy and efficiency of the new method are verified through a continuum mechanics example with an analytical solution. Examples of Brazilian disc and triaxial compression tests are used to verify the performance of this new method in simulating fracturing in geomaterials. Finally, dynamic loading on the Brazilian disc by a split Hopkinson pressure bar (SHPB) system is simulated, confirming that the new method effectively simulates dynamic fracturing problems. The study shows that computational results of the conventional FDEM highly depend on the penalty parameters of the cohesive elements. The adaptive FDEM overcomes these limitations with improved accuracy and efficiency by using adaptively inserted cohesive elements. © 2023 Elsevier Ltd