中文摘要：

针对海上风电基础结构疲劳损伤、疲劳寿命评价方法展开研究．区分疲劳荷载为单级疲劳荷载和多级疲劳荷载联合作用两种情况，考虑渐增型、往复型和正弦波型3种疲劳荷载作用方式，借助三桩导管架式海上风电基础，采用基于S-N曲线和Palmgren—Miner线性累计损伤法则的疲劳寿命估算方法对疲劳荷载作用F的结构疲劳损伤进行了计算，对结构整体寿命进行了评价；对单级疲劳荷载或多级疲劳荷载联合作用时，3种作用方式作用下的基础结构进行了疲劳分析，定义疲劳极限与疲劳荷载造成的应力水平的比值为安全系数，用以量化基硎；结构各部位或部件的抗疲劳能力，同时验证了加载顺序对于结构的锻炼效应．结果表明：基于S-N曲线干“Palmgren—Miner线性累计损伤法则的结构疲劳寿命估算，其依托的应力水平是单独获得的，忽略了加载顺序的影响；渐增型、往复型及正弦波型3种疲劳荷载作用形式财结构疲劳寿命的影响渐趋恶劣；南高到低的加载顺序对结构造成的损伤比南低到高的加载顺序要严重．

英文摘要：

The evaluation method of fatigue damage and fatigue life for foundation structure of offshore wind turbine is investigated. The fatigue damage and fatigue life of a tripod foundation is calculated using the method based on the S-N curve and linear damage cumulative rules （ Miner rules）. Three action modes of fatigue loads, named the increasing mode, the concussive mode and the sine mode, are considered in the fatigue analysis of the foundation under two kinds of fatigue loads, single load and multi-load. The ratio of the fatigue limit to the stress level caused by the fatigue load, named safety factor, is used to evaluate the ability of resisting fatigue. The forging effect caused by the load sequence is proved. The effect of load sequence is ignored in the linear accumulation theorem of fatigue damage for the independent stress level. The destructive action of fatigue load mode of concussive mode is greater than the increasing mode and less than the sine mode. The fatigue damage of the foundation under a decreasing fatigue load is more serious than the one under an increasing fatigue load.