摘要
冰载荷是诱发冰区海上风机结构疲劳破坏的重要因素,通常采用加装抗冰锥体的方式将海冰的挤压破坏转化为弯曲破坏,从而减小峰值载荷并削弱冰激振动。针对锥体风机结构在冰载荷作用下的疲劳寿命开展分析。基于渤海辽东湾某海域的现场监测数据确定了有效冰期、冰厚、冰速等疲劳分析参数,在冰速0~100 cm/s、冰厚0~30 cm范围内均匀划分50种疲劳工况,并将二者的联合概率分布作为疲劳工况的发生概率;采用具有粘结-破碎功能的球体离散单元构造海冰模型,计算风机与平整冰相互作用时的冰载荷时程及对应的热点应力;采用雨流计数法提取热点应力时程中的有效循环次数,根据S-N曲线和Miner线性累积损伤准则进一步计算其冰激疲劳寿命;最后将计算结果与通过锥体结构随机冰力函数构造冰载荷时程而得到的疲劳寿命相比较,验证了基于海冰离散单元模型的冰载荷时程构造方法的安全性与可靠性。
The ice load is an important factor that induces fatigue failure of offshore wind turbine structures in ice regions. The installation of anti-ice cones is generally used to convert the crushing failure of sea ice into bending failure, thereby reducing peak loads and weakening ice-induced vibrations. The fatigue life of the conical wind turbine structure under ice loads is analyzed. The fatigue analysis parameters such as effective ice period, ice thickness, and ice speed are determined according to the on-site monitoring data of Liaodong Bay,Bohai Sea. Fifty fatigue conditions are divided evenly within the ice speed range of 0~100 cm/s and the ice thickness range of 0~30 cm. The joint probability distribution of the two parameters is taken as the occurrence probability of fatigue conditions. The discrete element model of sea ice is constructed by spherical elements with bonding-breaking function. The ice load time history and corresponding hot spot stress when the wind turbine interacts with level ice is calculated. The rainflow counting method is used to extract the effective cycle times in the hot spot stress time history, and the ice-induced fatigue life is further calculated according to the S-N curve and Miner linear cumulative damage criterion. Finally, the calculation results are compared with the fatigue life obtained from the ice load time history constructed by random ice force function for conical structures, which verifies the safety and reliability of the ice load time history construction method based on the discrete element model of sea ice.
作者
刘圆
王键伟
巴越乔
季顺迎
LIU Yuan;WANG Jianwei;BA Yueqiao;JI Shunying(Offshore Engineering Technical Center of China Classification Society,Tianjin 300457,China;State Key Laboratory of Structural Analysis for Industrial Equipment,Dalian University of Technology,Dalian 116023,Liaoning,China)
出处
《船舶工程》
CSCD
北大核心
2022年第2期1-8,44,共9页
Ship Engineering
基金
国家重点研发计划重点专项(2016YFC1401505)
国家自然科学基金项目(42176241,52192693)。
关键词
海上风机结构
冰激疲劳
疲劳寿命
离散元方法
冰载荷
offshore wind turbine structure
ice-induced fatigue
fatigue life
discrete element method
ice load
