For industrial package (IP)-type transport containers for radioactive materials, a free drop test should be conducted under regulatory conditions. Owing to various uncertainties observed during the drop test, errors in drop angles inevitably occur. In IP-type metal transport containers in which the container directly impacts onto a rigid target without any shock absorbing materials, the error in the drop angle due to a slight misalignment makes a significant difference from the ideal drop. In particular, in a vertical drop, the error in the drop angle causes a strong secondary impact. In this paper, a numerical method is proposed to estimate the error in the drop angle occurring during the test. To determine this error, an optimization method accompanying a computational drop analysis is proposed, and a surrogate model is introduced to ensure calculation efficiency. Effectiveness of the proposed method is validated by performing the verification and comparison between the test and the analysis applied with the drop angle error.

对于用于放射性物质的工业包装（IP）型运输容器，应在监管条件下进行自由落体测试。由于在跌落测试期间观察到各种不确定性，因此不可避免地会发生跌落角度错误。在IP型金属运输容器中，其中的容器直接撞击在没有任何减震材料的刚性目标上，由于轻微的未对准而导致的倾角误差与理想的倾角有很大不同。特别是在垂直下落时，下落角度的误差会引起强烈的二次冲击。在本文中，提出了一种数值方法来估计测试过程中发生的倾角误差。为了确定此错误，提出了一种伴随计算下降分析的优化方法，为了保证计算效率，引入了替代模型。通过在测试和具有下降角误差的分析之间进行验证和比较，验证了所提方法的有效性。