舱内爆炸载荷下箱型舱室角隅连接结构设计

通过有限元软件LS-DYNA建立了舱内爆炸载荷下箱型舱室动响应数值模型，并借助文献试验结果验证了数值模型的可靠性，研究了平板型、内凹型、外凸型、箭头型、箭矢型、背面弧型等6种角隅连接结构对舱内爆炸载荷下箱型舱室变形、特征位置压力和破坏模式的影响，分析了内爆效应下角隅连接结构的失效机理。数值结果表明：舱壁角隅位置是舱内爆炸载荷作用下舱室易发生破坏撕裂的特征位置；相比无连接结构，平板型连接结构对舱壁最大塑性变形改善最大，降低幅度达到了31.9%；背面弧型连接结构能够使箱型舱室角隅等效塑性应变降低约60%；设置连接结构能够改变高塑性应变的发生位置，进而改变箱型舱室的破坏模式；采用平板型、内凹型、背面弧型连接结构的箱型舱室能够有效避免角隅失效破坏。

Design of corner connection structures of box-type cabins subjected to internal blast loading

Semi-armor-piercing warhead is likely to penetrate into the inner space of warship to induce severe damage. Published research indicated that the corner part of ship cabin tended to fail first. In present study, the novel design of corner structure aims to improve the capability of explosion-proof of ship cabin. Motivated by this idea, six kinds of typical corner connection structures were designed using the concept of weakening converged shock wave, improving the structure stress and strain state, coordinating deformation and transforming failure modes. The LS-DYNA software was employed to investigate the dynamic response of cabin structure subjected internal blast loading. Lagrange shell element and solid element based on multi-material ALE algorithm are used to simulate steel structure and air region, respectively. The interaction between shock wave and structure was fulfilled using fluid-structure interaction algorithm. The accuracy of the numerical model proposed in present paper was validated by comparing the published experimental results. Main attention of present study focuses on the effects of corner connection structure on the maximum deflection, corner pressure and deformation/failure mode of cabin structure. It attempts to explore the failure mechanisms of cabin structure. Simulation results confirm that the corner position of cabin structure is susceptive to fail under internal blast loading. Compared with the original structure without corner connection, the existence of corner connection structure can obviously reduce the plastic deformation of cabin structure. To be specific, the corner connection in the flat-plate form could reduce the maximum deflection by up to 31.9% relative to the original structure. In addition, the application of the corner connection in the arc shape could decrease the equivalent plastic strain by about 60%. Moreover, the existence of corner connection structure could ameliorate the position of high plastic strain and the failure modes of cabin structure. In present study, the corner connections in flat-plate form, concave form and arc shape could effectively avoid the failure behavior of cabin corner.