Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be...Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.展开更多
针对时变速度下的低碳配送需求,本文以配送总成本最小化为目标,构建考虑三维装载和时间窗约束的绿色车辆路径优化模型。模型考虑时变速度和实时载重对车辆燃油消耗量的影响。为准确计算行驶时间和油耗,采用二分K-means聚类算法对时段进...针对时变速度下的低碳配送需求,本文以配送总成本最小化为目标,构建考虑三维装载和时间窗约束的绿色车辆路径优化模型。模型考虑时变速度和实时载重对车辆燃油消耗量的影响。为准确计算行驶时间和油耗,采用二分K-means聚类算法对时段进行合理划分。设计两阶段算法求解模型:第一阶段采用自适应大规模邻域搜索(adaptive large neighborhood search,ALNS)算法以确定车辆配送路径;第二阶段采用遗传算法(genetic algorithm,GA)对货物进行三维装载顺序的可行性校验。算例结果表明,基于二分K-means聚类算法的时段划分方法能更精确地计算总成本,从而验证了本文所构建的模型和所设计的算法具有可行性和有效性。展开更多
基金financially supported by the Fourth Term of"333 Engineering"Program of Jiangsu Province(Grant No.BRA2011116)Youth Foundation of Jiangsu Province(Grant No.BK2012095)Special Program for Hadal Science and Technology of Shanghai Ocean University(Grant No.HAST-T-2013-01)
文摘Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.
文摘针对时变速度下的低碳配送需求,本文以配送总成本最小化为目标,构建考虑三维装载和时间窗约束的绿色车辆路径优化模型。模型考虑时变速度和实时载重对车辆燃油消耗量的影响。为准确计算行驶时间和油耗,采用二分K-means聚类算法对时段进行合理划分。设计两阶段算法求解模型:第一阶段采用自适应大规模邻域搜索(adaptive large neighborhood search,ALNS)算法以确定车辆配送路径;第二阶段采用遗传算法(genetic algorithm,GA)对货物进行三维装载顺序的可行性校验。算例结果表明,基于二分K-means聚类算法的时段划分方法能更精确地计算总成本,从而验证了本文所构建的模型和所设计的算法具有可行性和有效性。
