Abstract Evaluating marine system reliability requires considering the interaction of a limit state with the stochastic ocean excitation. Given a range of operational profiles, a relevant question is which sea states lead to the worst-case system responses, considering the effects of short and long-term variability. If the identified subset of operational profiles indeed leads to the worst-case system responses, it is possible to assess lifetime system performance without unnecessary computational effort via this directed set of conditions. Environmental contour methods identify rare sea states assumed to excite rare responses but generally do not include response dynamics when choosing these sea states. For systems with limit states involving combined loading or with multiple failure modes, rare environmental conditions may not exclusively lead to rare responses. In this case, the response cannot be severed from the identification of relevant sea conditions but should instead drive that identification. This paper illustrates a way to construct response-based reliability contours that identify sea states most relevant for analyzing rare responses of marine systems. These sea states are compared with sea states identified by environmental contours, showing the effect on perceived system risk levels when system dynamics, short-term response variability, and long-term environmental variability are considered.

中文翻译：

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考虑短期和长期可变性的复杂海洋系统的基于响应的可靠性等值线

摘要 评估海洋系统可靠性需要考虑极限状态与随机海洋激励的相互作用。考虑到短期和长期可变性的影响，给定一系列运行情况，一个相关的问题是哪些海况会导致最坏情况的系统响应。如果所识别的操作配置文件子集确实导致最坏情况的系统响应，则可以通过此定向条件集评估生命周期系统性能，而无需进行不必要的计算工作。环境等高线方法识别假设会激发罕见响应的罕见海况，但在选择这些海况时通常不包括响应动力学。对于具有涉及组合载荷或多种失效模式的极限状态的系统，罕见的环境条件可能不仅会导致罕见的反应。在这种情况下，响应不能与相关海况的识别分开，而是应该驱动该识别。本文说明了一种构建基于响应的可靠性等值线的方法，该等值线识别与分析海洋系统罕见响应最相关的海况。将这些海况与环境等高线确定的海况进行比较，显示在考虑系统动力学、短期响应可变性和长期环境可变性时对感知系统风险水平的影响。本文说明了一种构建基于响应的可靠性等值线的方法，该等值线识别与分析海洋系统罕见响应最相关的海况。将这些海况与环境等高线确定的海况进行比较，显示在考虑系统动力学、短期响应可变性和长期环境可变性时对感知系统风险水平的影响。本文说明了一种构建基于响应的可靠性等值线的方法，该等值线识别与分析海洋系统的罕见响应最相关的海况。将这些海况与环境等高线确定的海况进行比较，显示在考虑系统动力学、短期响应可变性和长期环境可变性时对感知系统风险水平的影响。