论文部分内容阅读
基于线性累积损伤准则的理论,对预应力混凝土风电塔架的疲劳可靠性评估进行研究.建立目标结构的有限元分析模型,根据目标结构所在场地模拟出不同风速等级下的随机风荷载时程曲线,采用雨流计数法统计目标结构疲劳关键点的应力幅及其相关的循环次数,根据损伤等效原则将其转化为常幅疲劳应力谱,结合风速分布规律,根据材料的S-N曲线和线性累计损伤准则算出结构的疲劳可靠指标及其剩余寿命.最后以某预应力风电塔架为例,对其进行疲劳可靠性分析,通过施加不同等级的风荷载时程样本,对塔架可能出现的疲劳破坏关键点进行计算,得出该塔架关键点处的疲劳可靠性指标与失效概率,并根据损伤程度评估其剩余寿命,进而可以评定风力发电塔架的安全可靠性.
Based on the theory of linear cumulative damage criterion, the fatigue reliability assessment of prestressed concrete wind power tower is studied. The finite element model of the target structure is established. According to the location of the target structure, the random wind load time history curve , The stress amplitude of the critical point of fatigue of the target structure and its related cycles were calculated by rain flow counting method. According to the principle of damage equivalence, it was transformed into the fatigue stress spectrum of constant amplitude. According to the wind speed distribution law and the SN curve and linear cumulative Damage criterion to calculate the fatigue reliability index of the structure and its remaining life.Finally, taking a prestressed wind turbine tower as an example, the fatigue reliability analysis of the tower is carried out, and the possible fatigue of the tower can be obtained by applying different grades of wind load time-history samples The key points of damage are calculated, and the fatigue reliability index and failure probability at the key points of the tower are obtained. The remaining life of the tower is evaluated according to the degree of damage, so that the safety and reliability of the wind power tower can be evaluated.