全封闭舱内爆炸载荷作用下薄板变形研究

在内爆炸载荷作用下，舱室内部长时程准静态压力载荷会对结构极限变形产生重要影响，使得其结构响应与敞开环境空爆下的情况有较大区别。计算分析了方形薄板在内爆炸载荷作用下动态响应，基于薄板在冲击载荷作用下的变形规律，提出了用于评估结构在内爆炸载荷作用下极限变形的无量纲损伤数。该无量纲损伤数考虑了舱室体积、炸药能量、结构几何尺寸及屈服强度等因素对内爆炸载荷作用下结构变形响应特性的影响。薄板变形的分析结果表明，结构极限变形与板厚比和无量纲损伤数之间存在明显线性关系，可通过拟合获得舱内爆炸载荷作用下结构极限变形的快速预报经验公式。提出的无量纲损伤数考虑了板大变形响应过程中的中面膜力效应和板厚影响，更加适合于分析薄板在内爆炸载荷作用下的塑性大挠度变形值。

On the Deformation of Thin Plates Subjected to Confined Blast Loading

In confined explosion, the quasi-static pressure in the enclosed space exists for a long time, and has an important effect on the ultimate deformation of structures so that the dynamic response of structures under confined blast loading is quite different from that under free air blast loading. The dynamic response of square plates under confined blast loading is analyzed. Based on the deformation regularity of thin plates under impact load, a new dimensionless damage number with clear physical meaning is proposed for the deformation prediction of structures under confined blast loading. The influences of the volume of enclosed space, explosive energy, structural dimensions,and strength of material on the deformation response of structure are considered for the dimensionless damage number. The analysis result shows that there is a clear linear relation between the mid-point deflection-thickness ratio and the new dimensionless damage number. An empirical expression with good correlation is presented for deformation prediction of structures under confined blast loading. The influences of membrane force and plate thickness on the structural response are considered in the new dimensionless damage number, which makes it have a wider application with regard to deformation prediction of plates subjected to confined blast loading, especially when the plate experiences large deflection.