水下近场非接触爆炸作用下固支方板破口计算

Crevasse computation for a clamped square plate subjected to near-field noncontact underwater explosion

为研究水下近场非接触爆炸载荷作用下固支方板的破口现象,根据能量守恒原理,假设冲击波能完全转化为结构的初始动能,进而转化为结构的塑性变形能。通过假设变形模式,建立塑性变形能与平板转角之间关系,进而求解平板转角。平板在中间出现破口后,裂纹向外扩展,呈现花瓣状,满足环向应变等于开裂应变条件时裂纹终止,破口达到最大。根据转角大小,可以求解破口尺寸。与通用有限元软件ABAQUS/EXPLICIT计算结果对比,两行吻合较好。工程上,可以利用所建立的计算方法估算破口大小。

The crevasse of a clamped square plate under near-field noncontact underwater explosion was studied here. According to conservation of energy, the energy of shock wave was transferred into the initial kinetic energy of the plate, and then converted into the distortion energy. By means of supposing a certain mode of distortion, the relations between the distortion energy and the slope of the plate were obtained. Therefore, the slope of the plate could be obtained. After the appearance of the damage at the center of the plate, the cracks extended toward to edges, like petals, till the ring strain was equal to the fracture strain. The crevasse reached the maximum. According to the values of the slope, the size of the crevasse could be solved. Compared with the results of the FEM software ABAQUS, the theoretical results were believable. So the proposed method could be used to estimate the crevasse size.