穿孔损伤位置对复合材料桨叶振动特性的影响
Influence of perforation damage position on composite blade vibration characteristics
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摘要: 以某直升机复合材料旋翼桨叶为参考, 在几乎没有对结构进行简化的情况下, 利用有限元软件ANSYS建立完整的有限元模型。在桨叶展向和弦向的不同位置模拟穿孔损伤, 与无损伤桨叶进行比较, 分析不同损伤位置对振动特性的影响, 得到振动特性与穿孔损伤位置的关系。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, 对各阶振动频率的影响程度既与损伤发生的位置有关, 也与主承力结构的损伤程度有关。桨叶根部损伤对各阶振动频率都有较大影响, 前缘和后缘损伤对摆振频率影响最大, 翼盒损伤对扭转频率影响最大; 大梁和后缘条的损伤面积越大对摆振频率的影响越大, 抗扭盒形件、 加强梁和大梁内抗扭层等承扭结构的损伤面积越大对扭转频率影响越大。Abstract: Finite element model of a helicopter whole rotor blade was established through ANSYS software. The relation between vibration characteristics and damage position was obtained by simulating perforation damage at different locations in the blade spanwise and chordwise directions. And comparison was carried out with that of the undamaged blade. The effect of different perforation locations on vibration performance was analyzed. The results show that damage cannot induce the change of vibration generally but affects vibration frequencies. The effect on vibration frequencies not only relates with the damage locations but also with the damage degree of major structures. The damage at blade root influences the whole vibration frequencies obviously, while the damage in the leading and trailing edge affect lag frequencies greatest. The damage in the wing box has maximum affect on the twist frequencies. The larger the damage in the trailing-edge strip and the main beam is, the greater the effect of lag frequencies is. The relation between twist wrap, spar and inner twist wrap in the main beam with the twist frequencies is the same with the lag vibration.