含穿孔损伤复合材料桨叶结构的振动特性

Vibration performance of composite blade segment with a perforation damage

现代直升机旋翼桨叶通常需要进行损伤容限分析与设计,损伤对桨叶结构振动特性的影响是其中的重要内容之一。利用有限元法对选定的直升机复合材料桨叶翼段进行了穿孔损伤后的振动特性分析,并与无损伤的翼段进行了比较,得到了振动特性与穿孔大小及其位置的关系。结果表明:旋转翼段的振动模态与静态翼段相同,但各阶频率有所提高;穿孔越大对翼段造成的损伤越大,但穿孔损伤没有改变翼段的振动模态,对翼段的振动频率影响也比较小;不同阶次的振动频率随穿孔的位置变化趋势各不相同,根部与前缘的穿孔损伤对翼段频率的影响较大。

Damage tolerance analysis and design are usually needed for modern helicopter rotor blades,while the influence of damage on the vibration performance of rotor blade structures is an important aspect.Vibration performance analysis was carried out here by the finite element method for a selected segment of helicopter composite blades with a perforation damage.Comparison of the result was performed with that of the blade segment without damage.The effect of the size and location of the perforation on vibration performance was obtained.The results show that the vibration modes of the rotating blade segment are the same with those of the still segment,while all the vibration frequencies have increased.The damage on the blade segment is more serious when the perforation size is greater.But the perforation damage does not change the modes of the blade segment,and the vibration frequency variations are small.The frequency variation depends on the perforation location.The perforations located in the blade segment root or front edge of the blade section have greater effect on the vibration frequencies of the blade segment.