This paper presents an analysis of the vibrational behavior of a rotating viscoelastic sandwich pre-twisted beams with a setting angle and with various viscoelastic stiffness laws. The governing equations of motion are derived using the Lagrange formulation and the assumed modes method. The obtained nonlinear eigenvalue problems are solved by using an iterative nonlinear eigensolver leading to complex eigensolutions composed of damped frequencies and loss factors with high accuracy. Further, the effects of the rotating speed, pre-twist angle, thickness ratio of core layer on the dynamic characteristics are investigated with taking into account the dependence of Young modulus with respect to frequency. Different numerical tests on rotating pre-twisted beams are performed for both isotropic and sandwich materials with a constant then a variable core modulus and the obtained results coincide very well with those provided in literature.

中文翻译：

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旋转预扭粘弹性夹层梁的模态分析

本文介绍了具有设置角和各种粘弹性刚度定律的旋转粘弹性夹层预扭梁的振动行为分析。运动的控制方程是使用拉格朗日公式和假定模式方法推导出来的。通过使用迭代非线性特征求解器来求解获得的非线性特征值问题，从而得到由阻尼频率和损耗因子组成的高精度的复杂特征解。此外，考虑到杨氏模量对频率的依赖性，研究了转速、预捻角、芯层厚度比对动态特性的影响。