装药形状对两端开口钢筒结构变形规律的影响

采用数值模拟与爆炸实验相结合的方式，研究了装药形状对两端开口圆柱钢筒结构变形规律的影响.采用显式动力分析软件LS-DYNA，并选用Johnson Cook模型模拟钢筒的动态变形，研究了方形、球形和柱形等不同形状装药对无加固圆柱钢筒塑性变形的影响规律，对比实验得到的残余变形测量结果，验证了钢筒计算模型和参数设置的有效性.同时，研究了不同长径比柱形装药对混凝土加固圆柱钢筒结构的影响.结果表明，在相同的装药量下，结构塑性变形与装药的几何形状密切相关.采用大长径比的装药形状，两端开口圆柱钢筒的环向变形明显增大.在设计防护结构时，必须高度重视装药形状对结构变形的影响.

Influence of Charge Shapes on Deformation Law of Open-End Steel Cylinder Under Internal Blast Loading

The influence of charge shape on the deformation law of open-end steel cylinder under internal blast loading was studied by means of numerical simulation and experiment. The dynamic explicit code LS-DYNA and the Johnson Cook model were used to simulate dynamic response of open-end steel cylinder. The numerical model and parameters were verified by comparison with experimental results of residual hoop strain of steel cylinder without concrete reinforcement under different charge mass. The influence of different shapes of charge, such as cuboid, sphere and cylinder, on the plastic deformation of open-end steel cylinder without concrete reinforcement were studied by numerical simulation at charge mass of 200 g. The aspect ratio of charge was changed from 0.25 to 4. The variation laws of overpressure, impulse and hoop strain of outer wall of steel cylinder were obtained. Based on this, the dynamic response of concrete reinforced steel cylinder under different aspect ratio was simulated. Compared with the experimental results, the deformation law was validated. The results show that the deformation of structure is closely related to the shape of charge. The hoop deformation of steel cylinder is larger when the aspect ratio is larger under the explosion of same charge mass. But the deformation will decrease when the aspect ratio is larger than a certain value. The influence of shape of the charge on the deformation of structure should be emphasized in the design process of protective structures.