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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=50 mm处矩形剖面和中部z=835 mm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。
The effect of the size and direction of the perforation damage on the vibration characteristics of the blade was studied by the established finite element model of the full blade. Taking the airfoil profile with z = 50 mm at the blade root and z = 835 mm in the middle as the research object, the perforation damage of different caliber was simulated on the leading edge, the wing box and the trailing edge respectively, and the vibration characteristics and the size of perforation damage The relationship between the vibration characteristics and the perforation damage direction is obtained by changing the direction of perforation damage of the leading edge. The results show that perforation damage generally does not change the vibration mode of each step, but changes the vibration frequency of each step. With the increase of injury caliber, the vibration frequency of each step is reduced. The damage occurred at the leading and trailing edges, with the most reduction in the frequency of the shimmy occurring in the wing box with the most reduction in torsional frequency. The influence of perforation direction on the vibration frequency of each stage is not only related to the location and structure of the damage but also to the geometry of the damage profile. For the rectangular section of the root, the angle between the perforation direction and the chord of the section is 75 ° and the effect of 105 ° is the largest, and the effect of the included angle close to 0 ° (180 °) is the most important for the central airfoil profile.