In order to obtain the dispersion rule of fragments about the asymmetric shell subjected to internal blast loading, two different cross section structures, concave-shaped and convex-shaped, were carried out by experimental and numerical methods. The simulation results well coincided with the experimental results, and the spatial distribution and fragment velocity were obtained. The optimal curvatures for the different concave structures changed from 4r to 6r (r represents the charge radius), as the central angle of concave structure changed from 90° to 120°. However, the optimal curvature changed weakly when the central angle of concave structure was larger than 120°. In addition, a formula which can rapidly predict the projection angle range was fitted for the convex structure. The conclusions can provide a reference for concave-shaped and convex-shaped structures to achieve a higher effectiveness of fragments.

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By analyzing the fragmentation distributions of a cylindrical structure and a specific structure, the necessity of parallel control to the fragments is presented. The shell shape of structures has an influence on the fragment spatial distribution. A new design method for the shell shape is proposed. To facilitate the establishment of the numerical model and the machining for relative experiments, the mathematical description of the theoretical calculated generatrix of the shell is simplified. The fragment spraying processes of the designed structures are simulated, and end effects are analyzed. Based on the theoretical design and plentiful simulation data, the relationships between the size of the parallel fragmentation structure and the optimized curvature radius of the shell are expressed by an equation. The equation is validated by numerical means and can be a reliable reference to the design of the parallel fragmentation structure.

The interaction of detonation waves was widely used in warhead design due to its ability to generate local high‐pressure regions. In this paper, the detonation interaction was investigated by experiments and finite element (FE) models. Experiments were conducted first to capture the fundamental dynamic fracture and fragmentation patterns and they served as a basis of validation for both the FE and analytical models. According to fracture surface, shear fracture is prior mechanism for steel‐plate fragmentation. The FE results indicated the dynamic fracture of steel plate was referred to the pressure difference between the collision area and its adjacent areas. A theoretical analysis of detonation wave interaction in explosive was carried out, and the relationship between the pressure at the collision area and adjacent areas was obtained. In the discussion part, the influencing factors and the optimal results for the plate fracture in the simulation calculation were carried out.