风力机叶片尾缘几何与结构构型对尾缘胶接剪切疲劳性能的影响研究

Evaluations of testing methods and suggestions for national standards of biomass stoves

叶片尾缘的几何形状不规则、生产局限性和复杂的运行环境使叶片尾缘的粘接对缺陷更加敏感。叶片作为风电机组的主要零部件,很多叶片由于尾缘粘接开裂导致叶片损伤。文章以风力机叶片尾缘粘接为研究对象,针对3种典型的几何外形,评估两种粘接线处理方式对尾缘胶接剪切疲劳性能的影响。首先,通过标准试验件测试得到结构胶的剪切疲劳性能S-N曲线;然后,利用叶片的结构模型得到胶层各个位置处的应力转换矩阵,再将动态疲劳载荷转换为应力时间序列;最后,采用雨流计数法和等寿命曲线得到胶的疲劳损伤。研究结果显示:在粘接线起点处将倒角处理成钝角可以降低局部范围的疲劳损伤;另外,在叶片合模后采用外包边对粘接进行加固补强,在一定范围内也能明显提高胶接的疲劳性能。

Blade is the main component of wind turbine.During wind field inspection,many blades were found to be damaged due to adhesion cracking of trailing edges.The trailing edge is more susceptible to damage due to the complex geometry,manufacturing technique,and operation conditions.This study aimed to investigate the influence of three typical shapes and chamfering type on the shear fatigue life of the trailing-edge adhesive joint using finite element and stress transformation matrix(STM)methods.The basic shear fatigue properties of the adhesive were obtained by standard component tests.The shear fatigue life of the blade trailing-edge adhesive joint under given load conditions was calculated using the fatigue properties of the adhesive and STM method.The results show that the local fatigue damage can be reduced by making the chamfering into obtuse angle,and the fatigue performance of the bonding can be improved obviously in a certain range when the blade is reinforced by the outer over-lamination.