双曲线型壳体结构爆炸载荷数值模拟

Numerical Simulation of large scaled hyperbolic shell structures under blast loading

利用数值模拟技术研究了地面爆炸冲击波与双曲线型壳体结构相互作用的模拟方法及作用于结构表面上爆炸载荷的预测方法.采用多物质欧拉与拉格朗日耦合算法,建立了不同比例距离下TNT炸药-结构耦合模型.通过参数分析,研究了结构表面爆炸载荷超压峰值沿环向和高度的分布规律,以及基本点反射超压峰值放大系数,并给出了拟合函数表达式.结果表明,结构背面（0°~90°区域）载荷超压峰值相比正面的超压峰值很小,在分析结构动力响应时可以忽略不计;载荷超压峰值沿环向及高度的分布与比例距离关系不明显,除环向局部分布需要用波形函数拟合外,其余部分均可以用线性函数拟合;基本点反射超压峰值放大系数与比例距离呈指数关系.结合已有的研究结论,建议了双曲线型壳体结构爆炸冲击载荷模型.

The numerical simulation of blast wave propagation and its interaction with hyperbolic shell structures are studied. The method for predicting blast loads on the structure is proposed. Using the multi-material Eulerian and Lagrangian coupling algorithm,several models considering fluid-structure interaction with different scaled distances are established. Parametric studies are conducted to investigate the peak overpressure distribution of blast loading along the height and the circumference of the structure. The reflected peak overpressure amplification factor of a basic point is also investigated. Fitting functions are then derived. The results show that reflected peak overpressure in the back of the structure( a region ranging from 0 degrees to 90 degrees) is so small that it is negligible in the analysis of structural dynamic response,compared to the same at the front of the structure. The peak overpressure along the circumference and height of the structure has little impact on the scaled distance. Except for the fact that the local circumferential distribution needs to be fitted with a wave function,the remaining part can be fitted with a liner function. The reflected peak overpressure amplification factor of the basic point has an exponential relationship with the scaled distance. Based on the research results,a blast load model for hyperbolic shell structures is proposed.