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
柔性负荷参与新型电力系统的优化调度对于提高新能源的消纳能力具有显著作用,但目前柔性负荷潜力尚未充分挖掘。针对这一问题,提出一种基于源荷预测的日前-日内优化调度方法。首先,采用麻雀搜索算法优化卷积长短时记忆神经网络(sparrow ...柔性负荷参与新型电力系统的优化调度对于提高新能源的消纳能力具有显著作用,但目前柔性负荷潜力尚未充分挖掘。针对这一问题,提出一种基于源荷预测的日前-日内优化调度方法。首先,采用麻雀搜索算法优化卷积长短时记忆神经网络(sparrow search algorithm is used to optimize the convolutional long-term and short-term memory neural network,SSA-CNN-LSTM)对新能源和负荷进行日前和日内功率预测;其次,根据柔性负荷的特性和需求响应灵活性,将负荷分为可平移、可转移和可削减负荷等不同类型,以考虑阶梯式碳交易成本的系统运行成本和污染气体排放最优为目标构建源荷互动的日前-日内两阶段低碳环境经济调度模型;最后,利用改进多目标灰狼算法(multi-objective grey wolf algorithm,MOGWO)对模型进行求解。算例分析表明,通过对柔性负荷分类参与调度较传统方式总成本降低8.6%、污染物排放减少4.1%、新能源消纳能力提高4.2%,在多时间尺度内显著降低新能源和负荷响应的不确定性并提高新型电力系统的低碳环境经济综合效益。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.
文摘柔性负荷参与新型电力系统的优化调度对于提高新能源的消纳能力具有显著作用,但目前柔性负荷潜力尚未充分挖掘。针对这一问题,提出一种基于源荷预测的日前-日内优化调度方法。首先,采用麻雀搜索算法优化卷积长短时记忆神经网络(sparrow search algorithm is used to optimize the convolutional long-term and short-term memory neural network,SSA-CNN-LSTM)对新能源和负荷进行日前和日内功率预测;其次,根据柔性负荷的特性和需求响应灵活性,将负荷分为可平移、可转移和可削减负荷等不同类型,以考虑阶梯式碳交易成本的系统运行成本和污染气体排放最优为目标构建源荷互动的日前-日内两阶段低碳环境经济调度模型;最后,利用改进多目标灰狼算法(multi-objective grey wolf algorithm,MOGWO)对模型进行求解。算例分析表明,通过对柔性负荷分类参与调度较传统方式总成本降低8.6%、污染物排放减少4.1%、新能源消纳能力提高4.2%,在多时间尺度内显著降低新能源和负荷响应的不确定性并提高新型电力系统的低碳环境经济综合效益。
