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中文核心期刊

内爆炸载荷下泡沫铝夹芯圆管塑性动力响应及能量耗散机理

PLASTIC DYNAMIC RESPONSE AND ENERGY DISSIPATION MECHANISM OF ALUMINUM FOAM SANDWICH CIRCULAR TUBE UNDER INTERNAL BLAST LOADING

  • 摘要: 通过实验、理论和数值模拟研究泡沫铝夹芯空心圆管在内爆载荷作用下的动态变形模式及吸能机制. 采用不同质量的球形乳化炸药进行爆炸试验. 结构轴向变形分为3个区: 大塑性变形区、绕塑性铰的刚性旋转区和无变形区. 在考虑环向膜力和轴向弯矩的情况下, 提出内爆作用下夹芯圆管动态响应的显式计算方法. 通过建立基于三维Voronoi算法的泡沫芯有限元模型, 探索结构能量耗散机制. 通过实验观测到的泡沫铝夹芯空心圆管在内爆载荷作用下的变形机制, 结合内外管的弯曲变形及芯层压缩, 给出了结构在响应过程中能量吸收的理论解. 以结构比吸能和外管中心挠度为控制参量求得夹芯圆管的最优解集. 进一步研究炸药质量、内外管直径、壁厚及芯层轴向梯度排列方式对结构动态变形模式和吸能机制的影响. 结果表明: 内管壁厚对外管中心线的挠度影响较大, 而芯层厚度和外管壁厚的影响较小; 如果夹芯圆管的轴向梯度结构从管轴向对称面到两端边缘呈对称递减分布时, 具有较好的抗爆性; 数值计算和实验测试结果均与理论预测吻合.

     

    Abstract: In this paper, the dynamic deformation mode and energy absorption mechanism of aluminum foam sandwich circular tube under internal blast loading were analyzed by experimental, theoretical, and numerical simulations. A series of blast experiments were performed using spherical emulsion explosives of different masses. Three axially deformed regions were divided for the structure: a large plastic deformation region, a rigid section moving around the plastic hinge, and an undistorted region. An explicit calculation method for the dynamic response of aluminum foam sandwich circular tube under internal blast loading was proposed considering the circumferential plastic membrane forces and the axial moment components. The FE model, based on a 3D Voronoi algorithm for the foam core, was developed to investigate the energy dissipation distribution mechanism of the structure. Through the experimentally observed deformation mechanism of the aluminum foam sandwich circular tube under the internal blast loading, combining the bending deformation of the internal/external tubes and the foam core crushing, a theoretical solution for the energy absorption of the structure in the response process was given. The optimal solution set of aluminum foam sandwich circular tube was obtained by using the specific energy absorption and the mid-point deflection of external tube as control parameters. The effects of the explosive mass, the diameter and the wall thickness of the internal and external tubes, and the axial arrangement of the core on the dynamic deformation mode and energy absorption mechanism were further investigated. The result showed that the wall thickness of the internal tube has a greater influence on the mid-point deflection of the external tube, while the wall thicknesses of the core layer and the external tube have a smaller influence on the mid-point deflection of the external tube; If the sandwich circular tube with the axial distribution of foam cores decreases from the center to the edge gradient core, a better anti-blasting performance could be observed of the structure; Both the numerical and experimental results were consistent with the theoretical predictions.

     

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