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针对涡扇发动机带凸肩风扇叶片,考虑凸肩接触带来的刚度和阻尼的非线性影响,采用Newton-Rapson迭代与多次谐波平衡相结合的方法,研究了结构设计参数对约束模态和振动响应的影响。研究结果表明:凸肩位置是影响叶片整体刚性和共振频率的关键参数,凸肩径向相对位置设计在55%~75%为宜,有利于提高叶片刚度和降低振动变形;轴向位置应靠近叶型质心,以提高凸肩的接触刚度和叶片一阶共振频率;啮合角和初始过盈量主要影响共振应力,而对共振频率影响很小。在此基础上,建立了带凸肩叶片的减振设计流程,首先通过优化凸肩径向位置提高叶片整体刚度,其次通过优化凸肩轴向位置提高低阶模态共振裕度,最后通过优化啮合角和初始过盈量抑制振动应力幅值。
Considering the non-linearity of the stiffness and damping caused by the contact of the shoulders, aiming at the fan blades with turbofan engine with shoulder blades, the Newton-Rapson iteration and multiple harmonic balance are combined to study the effect of structural design parameters on the restrained modes And the impact of vibration response. The results show that the location of the shoulder is the key parameter affecting the overall rigidity and resonance frequency of the blade. The design of the radial relative position of the shoulder should be 55% -75%, which is beneficial to increase the blade stiffness and reduce the vibration deformation. The axial position should be close to Leaf center of mass in order to improve the contact stiffness of the shoulder and the first-order resonance frequency of the blade. The engagement angle and the initial interference mainly affect the resonance stress but have little effect on the resonance frequency. On this basis, the damping design flow with the shoulder blade is established. Firstly, the overall stiffness of the blade is improved by optimizing the radial position of the shoulder. Secondly, the low-order modal resonance margin is improved by optimizing the axial position of the shoulder. Finally, The meshing angle and the initial interference amount suppress the vibration stress amplitude.