【摘要】 研究了弹性耦合对复合材料桨叶动特性和气弹稳定性的影响,所采用的结构模型考虑了剪切变形、剖面面外翘曲变形和复合材料弹性耦合。推导出同时考虑剪切和翘曲影响的小应变、中等变形梁的应变-位移关系,并构造出21个自由度梁单元,应用Hamilton原理推导出桨叶运动的有限元方程。在此基础上,对三种不同构型的复合材料桨叶进行固有频率计算和气弹稳定性分析。计算结果表明:尽管复合材料弹性耦合对桨叶固有频率的影响非常小,但却改变了固有振型分布,使桨叶挥舞-摆振-扭转运动之间存在耦合;弹性耦合对桨叶气弹稳定性有很大的影响;正的挥舞-扭转耦合使得摆振一阶稳定性增加,负的挥舞-扭转耦合却使摆振一阶稳定性下降。更多还原

【Abstract】 The aeroelasticity of helicopter composite rotor blades with elastic coupling is analyzed.The structural model in this analysis includes the effects of transverse shear deformation,out-of-plane warping and aeroelastic coupling. A 21-DOF beam finite element,including transverse shear DOF and warping DOF,is developed for analysis.The governing differential equations of motion for a hingeless rotor are derived using the Hamilton’s principle.Three different composite blade configurations are conducted for comparison.The results show that changes in blade frequencies are very small,however,the mode shapes are significantly changed considering elastic coupling.The blade stability in hover is strongly affected by the ply-induced composite couplings.Positive flap-torsion coupling has a stabilizing effect on the lag mode damping.Negative flap-torsion coupling has a destabilizing effect on the lag stability.更多还原