To study the ability of shaped charges to penetrate typical ship targets, two shaped charges with the same diameter of 200 mm but different configurations are designed to generate two forms of jetting projectile charge (JPC). Based on the protective structure of typical ship targets, static penetration tests are performed using the two types of a shaped charge with copper liner and 10-layer spaced targets with a total span of 16 m which is made in 921A steel. Numerical simulations under the same working conditions are also carried out. It is found that the simulation results of the penetration depth and the number of layers of target perforated by the JPC are much greater than the experimental results. In fact, the JPC breaks up when moving to a certain distance, and the JPC segments after breakup have a transverse drift velocity, causing the segment to deviate from the original penetrating channel. The influence of drift velocity after JPC fracture cannot be considered in numerical simulation, resulting in significant differences between numerical simulation and experimental results. Thus, this paper proposed a segment-based numerical simulation method and analyzed the penetration process of JPC fragments after JPC fracture. Combined with experimental results, the radial motion after JPC fracture and the final distribution of penetration holes can be well revealed. It is found that the penetration depth and the number of layers of target perforated by the JPC depend on the tip velocity of each segment and the jet length.

A shaped charge liner driven by a strong electromagnetic field instead of explosives is a new way to form a jet. In this article, a new liner structure is performed, and a CQ-4 device of the Institute of Fluid Physics, Chinese Academy of Engineering Physics is used to load the liner. The jet forming and penetration power of conical liners under strong electromagnetic loading are tested and theoretically analyzed. Experimental results are in good agreement with the theoretical calculation. The results show that the 1- and 1.5-mm-thick liners have formed jets, but the liner with 2-mm wall thickness has failed to form an effective jet. And coming to the conclusion that under the loading conditions studied in this research, the jet velocity and penetration power decrease with the increase in the liner thickness. The liner structure is compared with Grace's in his experiments and was found that it can improve the electromagnetic energy utilization rate, the peak current increasing by 9.6% and the jet tip velocity increasing by 8%. The influence of the cone angle of the liner on jet forming is also verified by a theoretical calculation taking into account the jet tip velocity, jet length, and the penetration power that increase with the decrease in cone angle.

The Lambda wing UAV inevitably needs to adjust the lift coefficient and pitch moment by controlling the flap when encountering multiple flight states. Inspired by the natural morphing mechanisms of bird wings, this study draws upon bionic principles to explore a seamless morphing trailing edge (SMTE) design that mimics the smooth and continuous deformation observed in avian flight. A comparative analysis between SMTE flaps and traditional hinge flaps highlights the superior rearward stealth performance of SMTE flaps in the direction angles of 120° to 140°, along with a reduction in aerodynamic drag. During the optimization, a model based on flexible wing ribs and elastic skin was established, and statistical analysis revealed a strong linear correlation between the maximum lift coefficient provided by the flaps and the overall lift-to-drag ratio. Consequently, the optimization process omitted the enhancement of the comprehensive lift-to-drag ratio during the flap deflection. Additionally, a deep Neural Network Surrogate Model was introduced to streamline the computationally intensive aerodynamic calculations. Ultimately, an MOGA-2 optimization model incorporating local deep Neural Network Surrogate Models was utilized to achieve the comprehensive optimization of aerodynamic and stealth characteristics, through an adjustment of the wing rib and skin proportions. The UAV rearward RCS and the maximum lift coefficient provided by the flaps have decreased by 2.8% and increased by 6.6%, respectively.

This study develops a thermoviscoplastic model that incorporates an effective through-thickness microstructural length into the Hill48 yield criterion for shaped-charge liners. The model is implemented in the axisymmetric Hot Optimal Transportation Meshfree (HOTM) framework and verified through directional-yield and material-coordinate transformation tests. An isotropic bulk reference is adopted to isolate the thickness-dependent directional correction in comparisons with conventional J2 plasticity. Comparison with a published experiment supports the predicted global jet-formation response, while independent validation of the microstructural mechanism remains necessary. For the representative numerical case, the proposed model predicts higher jet-tip velocity, greater jet length, and modified deformation localization. A Walsh-type plastic-instability criterion is used to bracket the critical liner thickness for three charge calibers. The nominal critical thickness increases with caliber, whereas its normalized value decreases, indicating a departure from proportional scaling within the investigated range. These results demonstrate the sensitivity of the predicted jet response to the assumed thickness-dependent constitutive description. The findings remain limited to the adopted phenomenological parameters and investigated configurations and do not establish a general scaling law. The framework provides a basis for subsequent material calibration and experimental validation.