径向荷载作用下多排圆柱壳八塑性铰变形行为研究

Eight-plastic-hinge deformation behavior of multi-row cylindrical shells subjected to radial pressure

研究圆柱壳的径向动力变形行为,有助于构造具有高吸能率的抗爆结构.与单个圆柱壳径向受压四塑性铰变形机构相比,多排圆柱壳因受相邻两圆柱壳横向约束,其变形特征有所不同.通过对多排圆柱壳的受力分析、准静态压力实验、小药量爆炸实验和数值模拟研究,明确了径向荷载作用下多排圆柱壳的塑性变形行为,提出并确立了八塑性铰变形机构,即由四个塑性区边缘不断外移的移动铰和四个塑性区相对大小不变的固定铰组成.进一步,确定了转动区尺寸及塑性铰位置,计及应变率效应和材料硬化效应,建立了八塑性铰机构塑性铰附近的塑性弯矩表达式,为用模态法求解多排圆柱壳的大变形问题奠定了基础.

Study on the radial dynamic deformation behavior of cylindrical shell is helpful to constitute an anti-explosion structure. Due to the existence of two adjoining cylindrical shells, the deformation mode of multi-row cylindrical shells subjected to radial pressure was not the four-plastic-hinge framework. Based on mechanics analysis, quasi-static experiment, small explosion experiment and numerical simulation, the authors establish that the plastic deformation behaviors of multi-row cylindrical shells under radial pressure and the number of plastic hinges is eight. This eight-plastic-hinge framework consists of four moving hinges that the edges of plastic zone move ceaselessly outward and four fixed hinges that the comparative size of plastic zone is invariable. Furthermore, the size of rotational part and the place of plastic hinges are calculated. In view of the dynamic strain rate and strain hardening of material, the expressions of the plastic bending moments near the plastic hinges are presented. These results give us a theoretical foundation to use modal method to solve the large deformation problem of multi-row cylindrical shells.