The initiation and propagation of cracks involve the abrupt transition of materials from continuous media to discrete separation, posing significant challenges to numerical simulations. In this paper, an enhanced bond...
The initiation and propagation of cracks involve the abrupt transition of materials from continuous media to discrete separation, posing significant challenges to numerical simulations. In this paper, an enhanced bond-breaking model base on the pseudo-spring model is developed to model the failure process of rock-like materials. The new model maintains the integrity of the particle support domain and avoids unphysical phenomena during bond breakage. And this study achieved the prefabrication of initial cracks by artificially controlling bond breakage. In addition, the artificial stress and viscosity and kernel gradient correction are applied to improve the computational accuracy and stability. Several examples are investigated to verify the efficiency of the present SPH method with the enhanced damage model, comparing with experimental results, the present SPH method accurately captures the material's actual damage behavior, providing a valuable reference for rock material failure analysis.
Through dynamic compaction tests with tamping energies of 1500, 2000, and 2500 kN•m of an embankment section in the PingShan-ZanHuang Expressway, the compression deformation behavior of the tamping settlement, soil de...
详细信息
The stiffness of a shell is conclusively influenced by the distribution of its material. To obtain the optimal material distribution of 3D spatial shells at a reasonable computational cost, this paper proposes a layer...
The stiffness of a shell is conclusively influenced by the distribution of its material. To obtain the optimal material distribution of 3D spatial shells at a reasonable computational cost, this paper proposes a layer-by-layer optimization strategy with controllable deformation. In this strategy, the 3D spatial shell is divided into finite layers in the thickness dimension, and the deformations of each layer are constrained by the presupposed target volume in the matching optimization cycle. During the optimization cycle, to minimize the computational cost, we use a dimension-reduced level set method (DR-LSM), wherein the optimal 2D plane layers of the 3D spatial shell are iterated in the 2D domain using a uniform initial design. The optimized 2D plane layers are sequentially stacked to construct the optimal material distribution of the 3D spatial shell. Both numerical calculations and experimental results demonstrate that the proposed strategy successfully achieves an optimal material distribution for 3D spatial shells while preserving their original geometric characteristics and eliminating cavity structures. Notably, the stiffness of shells with different curvatures is significantly enhanced without altering its volume and mass, proving the stability and effectiveness of this strategy.
Background: Loop closure detection is a crucial part in robot navigation and simultaneous location and mapping (SLAM). Appearance-based loop closure detection still faces many challenges, such as illumination changes,...
详细信息
To achieve robust and accurate state estimation for robot navigation, we propose a novel Visual Inertial Odometry(VIO) algorithm with line features upon the theory of invariant Kalman filtering and Cubature Kalman Fil...
详细信息
Building a subgrade on the slope foundation is common for highway constructions in China. Under different hydrogeological conditions, the stability and differential settlement are the main problems for the constructio...
Building a subgrade on the slope foundation is common for highway constructions in China. Under different hydrogeological conditions, the stability and differential settlement are the main problems for the construction of the subgrade. In order to study the parameters that influence the stability and deformation of subgrade, based on the cross-section of a mountainous region highway, those simulations were conducted to study the influence of subgrade height, subgrade width, embankment slope angle, and slope foundation angle on the stability and pattern of embankment. The results showed that the allowable filling height is 15 m; otherwise, there is a large risk of the slope sliding. Further, it was found that the maximum vertical deformation on the right shoulder of the embankment increases with an increase in the angles of the slope of the foundation. These results provide references for future highway constructions and design works in mountainous areas.
Through dynamic compaction tests with tamping energies of 1500, 2000, and 2500 kN•m of an embankment section in the PingShan–ZanHuang Expressway, the compression deformation behavior of the tamping settlement, soil d...
Through dynamic compaction tests with tamping energies of 1500, 2000, and 2500 kN•m of an embankment section in the PingShan–ZanHuang Expressway, the compression deformation behavior of the tamping settlement, soil deformation around the tamping rammer, consolidation depth, and dynamic stress of dynamic compaction were comprehensively tested. Comparative analyses of field data under three different tamping energies suggested that the optimal tamping energy, number of strikes, and vertical effective tamping depth for this embankment are 2000 kN•m, six, and 5 m, respectively. The field test data proving that dynamic compaction has a significant effect on this embankment.
暂无评论