The problem of assessing damage due to explosions of cylindrical pressure vessels is considered. The attention is focussed on a prediction of the arrangement of cracks in the vessel wall prior to its explosion. This arrangement of cracks is called the failure pattern. It is seen as essential information for forecasting ejection and projection of fragments generated by an explosion. Thermally induced explosions known as boiling liquid expanding vapour explosions are studied. The problem of prediction of failure patterns is formulated as a problem of estimating probabilities of these patterns. The scarcity of data on occurrences of failure patterns in the past explosion accidents was an incentive to estimate the failure pattern probabilities by means of Bayesian statistics. The main finding of the study is that the failure pattern probabilities can be handled within the Dirichlet-multinomial model and the epistemic uncertainty in these probabilities expressed by Dirichlet prior and posterior distributions. The Bayesian estimation of failure pattern probabilities is viewed as a way allowing to introduce the prediction of vessel fragmentation into the formal probabilistic risk analysis. The so-called minimally informative Dirichlet prior distribution is suggested for the probability estimation as a prior suitable to Bayesian updating with scarce data. It is stated that currently the probabilistic prediction of failure patterns on the basis of past accident data is the only practicable way to assess the potential type of vessel fragmentation. A conventional (deterministic) mechanical and/or metallurgical analysis does not provide reliable models for failure pattern prediction in case of explosions under study.

考虑了圆柱形压力容器爆炸损伤的评估问题。注意力集中在容器壁爆炸前裂缝排列的预测上。这种裂纹排列称为失效模式。它被视为预测爆炸产生的碎片的抛射和投射的重要信息。研究了称为沸腾液体膨胀蒸汽爆炸的热致爆炸。故障模式的预测问题被表述为估计这些模式的概率的问题。过去爆炸事故中发生故障模式的数据稀缺，这促使人们通过贝叶斯统计来估计故障模式概率。该研究的主要发现是故障模式概率可以在狄利克雷多项式模型中处理，这些概率中的认知不确定性由狄利克雷先验和后验分布表示。故障模式概率的贝叶斯估计被视为允许将血管破裂的预测引入正式概率风险分析的一种方式。建议将所谓的最小信息 Dirichlet 先验分布用于概率估计，作为适用于稀缺数据的贝叶斯更新的先验。据称，目前根据过去的事故数据对故障模式进行概率预测是评估潜在船舶破碎类型的唯一可行方法。