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针对海洋平台服役周期内突发致损事件“小概率,高风险”的非比例后果特性,综合考虑常规疲劳退化与突发致损的耦合作用,定量分析了局部突发致损的直接后果及结构倒塌失效的潜在间接后果。从风险分析理论的角度,提出海洋平台结构风险鲁棒性指标,并基于Monte-Carlo随机模拟,建立了风险鲁棒性的评价方法及评价流程。通过相应算例,分析海洋平台结构全寿命周期内风险鲁棒性指标的动态特征及影响因素,并讨论了检修行为对结构鲁棒性控制的作用。模拟示例结果表明,在平台服役后期,初始损伤及疲劳退化对风险鲁棒性指标的影响愈加显著,完好平台结构的风险鲁棒性指标明显高于含初始损伤平台,至服役的第30年,两种平台的风险鲁棒性指标分别由1下降至0.913和0.67。同时,4种不同突发事件单独作用下的模拟结果表明,对风险鲁棒性影响最为显著的突发事件是爆炸,其后依次是船舶碰撞、突发火灾和重物坠落。突发事件发生后采取快修措施可有效提高其风险鲁棒性指标,且为保证平台结构维持合理的风险鲁棒性水平而采取“非完好维修”是更为经济可行的选择。
Aiming at the nonproportional consequence of sudden damage event and “small probability and high risk” during the service life of offshore platform, considering the coupling effect of conventional fatigue degradation and sudden damage, the direct local damage damage is quantitatively analyzed Consequences and the potential indirect consequences of structural failure. From the perspective of risk analysis theory, the robustness of offshore platform structural risk is proposed. Based on the Monte-Carlo stochastic simulation, the risk robustness evaluation method and evaluation process are established. Through the corresponding examples, the dynamic characteristics and the influencing factors of the risk robustness index over the life cycle of the offshore platform are analyzed. The role of maintenance behavior on the structural robustness control is also discussed. The simulation results show that the initial damage and fatigue degradation have a more significant impact on the risk robustness index in the late stage of the platform service. The robustness index of the intact platform structure is significantly higher than that of the initial damage platform. In the 30th year of service, The risk robustness index for both platforms dropped from 1 to 0.913 and 0.67 respectively. Simultaneously, the simulation results under the influence of four different emergencies show that the most significant emergent event that has the most significant impact on the risk robustness is the explosion, followed by the ship collision, sudden fire and heavy object crashes. Taking emergency repair measures after emergencies can effectively improve the risk robustness index and adopting “non-perfect maintenance” is a more economically feasible option to ensure that the platform structure maintains reasonable risk robustness.