摘要
建立一种悬停状态下无轴承复合材料旋翼气动弹性稳定性分析新模型。修正Bauchau大变形梁理论建立无轴承复合材料旋翼桨叶的非线性应变-位移关系,据复合材料特点推导桨叶本构关系并构造新的24自由度梁单元,将桨叶视为多路传力系统,应用Hamilton原理建立桨叶运动有限元方程,分析悬停状态下具有复合材料柔性梁无轴承旋翼气动弹性稳定性。数值计算结果表明:采用该模型的无轴承旋翼气动弹性稳定性计算结果与试验数据吻合程度较传统中等变形梁理论更好;具有负变距-摆振耦合的复合材料柔性梁结构可提高无轴承旋翼气动弹性稳定性及正变距-摆振耦合结构降低旋翼气动弹性稳定性;负铺层角较大小相同正铺层角旋翼气动弹性稳定性更好;铺层厚度减少有利于增加旋翼气动弹性稳定性。
A new approach was presented to analyze aeroelastic stability of a bearingless composite rotor in hover. Nonlinear strain-displacement relations were presented using a large deflection beam theory modified from Bauchau's beam mode. Assuming the stress components in the cross-section be equal to zero, constitutive relations for a Composite blade were built. A new 24 degree-of-freedom finite element was developed for analysis and the finite element equations of motion for a blade were derived from Hamilton's principle. Aeroelastic stability of a bearingless rotor with a composite flexbeam in hover was investigated. Numerical results showed that a negative ply angle stabilizes the first lag mode while a positive ply angle destabilizes the first lag mode; eastic pitch-lag couplings caused by ply lay-up of flexbeam have significant effect on aeroelastic stability of a bearingless composite rotor; negative pitch-lag coupling has a stabilizing effect on lag modal damping; positive pitch-lag Coupling has a destabilizing effect on lag modal damping. A reduction in ply thickness increases lag modal stability.
出处
《振动与冲击》
EI
CSCD
北大核心
2012年第22期151-156,共6页
Journal of Vibration and Shock