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为实现某大型水平轴风力机塔筒顶部焊缝的抗极限与疲劳强度设计,建立塔筒顶部的有限元模型。模型充分考虑螺栓预紧力、轴承刚度、部件间接触等非线性因素,考察了极限工况下焊缝的结构强度。基于非线性有限元模型,施加不同幅值大小、方向的弯矩,采用线性插值方法获取焊缝的时序应力值。通过雨流计数计算得到焊缝的累积损伤,并确定最大累计损伤部位。考察不同壁厚下焊缝的极限与疲劳强度,并给出结构优化方案。结果证明了所提出方法的可行性和有效性。
In order to achieve the design of the ultimate strength and fatigue strength of the weld bead on the top of a large horizontal axis wind turbine, a finite element model of the top of the tower was established. The model fully considers the non-linear factors such as the bolt pretightening force, the bearing rigidity and the contact between the components, and examines the structural strength of the weld under the limit working conditions. Based on the nonlinear finite element model, the bending moments of different amplitude, magnitude and direction were applied, and the linear interpolation method was used to obtain the timing stress of the weld. The cumulative damage of the weld is calculated by rain flow counting and the maximum accumulated damage location is determined. Inspect the limit and fatigue strength of the weld under different wall thickness and give the structural optimization scheme. The result proves the feasibility and effectiveness of the proposed method.