Last modified: 2023-07-16
Abstract
Structural blast problems involve complex structure geometry, nonlinear material constitutive relation and nonlinear shock-structure interaction. Besides, these problems are always accompanied with dynamic fracture phenomena and structural damage, resulting in small fragments of thin geometry and fresh FSI interface, which bring great numerical difficulties and challenges to traditional FSI algorithms. Therefore, the development of efficient and powerful algorithms to simulate these phenomena remains a challenging task.
This talk will present our recent developed immersed multi-material finite volume-material point method (iMMFVMPM)[1][2] for structural blast damage problems. The multi-material finite volume method (MMFVM)[3] based on diffused interface method (DIM) is adopted as fluid solver to simulate the propagation process of detonation waves, while the material point method (MPM)[4] is employed as solid solver to simulate the structure extreme deformation. To couple the MMFVM and MPM, we developed an immersed boundary method (IBM)[5], named as Lagrangian continuous-forcing IBM (lg-CFIBM), in the frame of continuous forcing approach with a compact support area for the immersed boundary conditions. The lg-CFIBM can guarantee the boundary velocity conditions strictly at each time step and thus reproduce the shock wave structure exactly. Meanwhile, it has no need to reconstruct the FSI interface anymore, which avoids the numerical difficulty with the treatment of freshly generated FSI interface in traditional IBM.
The proposed iMMFVMPM is capable of simulating the dynamic fracture process under blast loading, in which small fragments of thin geometry and fresh FSI interfaces will be generated. Several numerical examples are studied to verify and validate the proposed method, and numerical results are in good agreement with available experiments.