摘要:
通过建立的全桨叶有限元模型, 研究了穿孔损伤的大小和方向对桨叶振动特性的影响。以桨叶根部z=50mm处矩形剖面和中部z=835mm处翼型剖面为研究对象, 分别在前缘、 翼盒和后缘模拟不同口径的穿孔损伤, 得到振动特性与穿孔损伤大小的关系, 并通过改变前缘的穿孔损伤方向, 得到振动特性与穿孔损伤方向的关系。结果表明, 穿孔损伤一般不会引起各阶振动模态的改变, 但会使各阶振动频率发生变化。随着损伤口径的增大, 各阶振动频率都降低。损伤发生在前缘和后缘, 摆振频率降低最多, 发生在翼盒, 扭转频率降低最多。穿孔方向对各阶振动频率的影响不仅与损伤的位置和结构有关, 还与损伤剖面的几何形状有关。对于根部矩形剖面, 穿孔方向与剖面弦向夹角为75°和105°对摆振频率影响最大, 对于中部翼型剖面, 夹角接近0°(180°)对摆振频率影响最大。
关键词:
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复合材料
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桨叶
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穿孔损伤
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振动特性
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有限元
Abstract:
The finite element model of the whole rotor blade was established to study the effect of perforation damage size and direction on vibration performance.For the rectangular section of blade root at z=50mm and the leading edge section of its midst at z=835mm, the relation between vibration performance and size of perforation damage was obtained by simulating different holes of perforation damage in the leading edge, wing box and trailing edge respectively.And the relation between vibration performance and perforation damage direction was also obtained by means of changing perforation damage direction of the leading edge.It shows that the damage cannot induce the change of vibration modality but affects vibration frequency.As the perforation hole is increased, the vibration frequencies go down wholly.When the damage arose in the leading and trailing edge, lag frequencies go down great, and lowing twist frequency mostly occurred in the wing box area.The effect of perforation on vibration frequency is concerned with not only the perforation location and structure, but also with the geometry of perforation section.When the perforation direction is at the angle with 75° and 105° to the blade chordwise in the root rectangular section, lag frequency is influenced maximum.While in the midst airfoil section, as the angle approaching to 0°(180°), twist frequency is effected greatest.