The coupled acoustic-structural analysis strategy in ABAQUS is frequently employed to perform UNDEX resistance performance evaluation of structures to date. Proper consideration of the shock loading on the structure is vitally important for a coupled acoustic-structural UNDEX analysis. The authors carried out a numerical simulation of a partially submerged circular RC column undergoing an UNDEX shock loading. The study focuses on two factors that might affect the shock loading implementation: (a) the duration of an UNDEX shock front (the rise time), and (b) the employed acoustic-wave formulation type (scattered or total). With the total wave formulation, the calculated kick-off displacements of the column in the rise time = 30 and 40 μs cases are reasonably consistent with the experimental one (Zhuang et al., 2020). The simulation shows that the predicted structural response of the column is sensitive to the rise time. The findings suggest that a period of time of 30–40 μs could be reasonable and practical for small-explosion-equivalent scenarios. Note that the present conclusion is limited to small explosive charges but invalid for large UNDEX loadings (usually having much “higher” frequencies). The study also shows that the scattered wave formulation is not applicable for the current case due to the simulated negative pressure loading on the column. The total wave formulation should be used for low-stiffness structures to properly simulate possible local cavitation. The most important limitation lies in the planar incident wave assumption that makes the current findings less generalizable to other structures with larger lengths/heights or stiffnesses.

迄今为止，ABAQUS中的耦合声结构分析策略经常用于对结构进行UNDEX阻力性能评估。适当考虑结构上的冲击载荷对于耦合声结构UNDEX分析至关重要。作者对承受UNDEX冲击载荷的部分浸入式圆形RC柱进行了数值模拟。该研究集中在可能影响冲击载荷实施的两个因素上：（a）UNDEX冲击前沿的持续时间（上升时间），以及（b）使用的声波公式类型（分散的或全部的）。使用全波公式，在上升时间分别为30和40μs的情况下，计算出的色谱柱的启动位移与实验值（Zhuang等，2020）合理地一致。仿真表明，预测的柱结构响应对上升时间敏感。研究结果表明，对于等效于小爆炸的场景，30到40μs的时间段可能是合理且实用的。注意，本结论仅限于较小的炸药装药量，但不适用于较大的UNDEX装料量（通常具有较高的“较高”频率）。研究还表明，由于在柱上模拟了负压，因此散射波公式不适用于当前情况。总波公式应用于低刚度结构，以正确模拟可能的局部气蚀现象。最重要的限制在于平面入射波假设，这使得当前的发现难以推广到其他具有更大长度/高度或刚度的结构。