Tower is an important fundamental component of large-scale wind turbines.The fatigue performance of the tower welded part directly affects the running safety and reliability of wind turbines.A fatigue life predicting ...Tower is an important fundamental component of large-scale wind turbines.The fatigue performance of the tower welded part directly affects the running safety and reliability of wind turbines.A fatigue life predicting method for the longitudinal welding seam of the tower is proposed in this paper.Under the precondition of satisfying the limit strength,the time series stress of each working condition is obtained by DIN18800-4 section stress calculation.Combined with the rain-flow counting method and the Miner linear cumulative damage theory,the fatigue life of the tower longitudinal weld is predicted.The results show that the tower structure meets the design requirement,and the feasibility and effectiveness of the method are verified.展开更多
文摘目的:研究稳定型冠心病合并H型高血压患者血管内超声虚拟组织学冠脉斑块特征。方法 52例稳定型冠心病且合并高血压患者,依据血浆同型半胱氨酸(Hcy)水平分为合并H型高血压组、合并非H型高血压组。所有患者行冠脉造影检查确诊,计算3支血管病变比例及Gensini评分;对冠脉靶病变进行血管内超声检查及虚拟组织学分析,研究两组血管重构及斑块病变特征。结果与合并非H型高血压组比较,合并H型高血压组冠脉3支血管病变比例增高(57.14%vs 41.67%)、Gensini评分增高(30.82±7.18 vs 26.35±4.27),差异有统计学意义(P<0.05);合并H型高血压组血管重构指数、正性重构比例、斑块脂质坏死组织面积、纤维脂质组织面积较合并非H型高血压组升高(P<0.05),斑块钙化组织面积、纤维组织面积两组比较差异无统计学意义(P>0.05)。相关分析显示血浆Hcy水平与3支血管病变比例、Gensini评分、血管重构指数、正性重构比例、脂质坏死组织面积、纤维脂质组织面积存在正相关关系。结论稳定型冠心病合并H型高血压患者,其高血浆Hcy水平不但影响冠脉病变的范围和严重程度,还可能进一步加重血管重塑及斑块组分的差异,造成斑块不稳定趋势。
基金the Special Research Fund for the Natural Science Foundation of Inner Mongolia Autonomous Region(No.2019MS05070)。
文摘Tower is an important fundamental component of large-scale wind turbines.The fatigue performance of the tower welded part directly affects the running safety and reliability of wind turbines.A fatigue life predicting method for the longitudinal welding seam of the tower is proposed in this paper.Under the precondition of satisfying the limit strength,the time series stress of each working condition is obtained by DIN18800-4 section stress calculation.Combined with the rain-flow counting method and the Miner linear cumulative damage theory,the fatigue life of the tower longitudinal weld is predicted.The results show that the tower structure meets the design requirement,and the feasibility and effectiveness of the method are verified.
