Mass unbalance, shaft misalignment, rotor asymmetry, and force due to rotor weight are the main causes of vibrations in rotary machines especially when the shaft is not symmetric. Although extensive researches have been carried out to determine the effect of each on the increase of vibration levels far, there has been no clear study on the simultaneous existence of all these parameters and their interactions. In this research, the model is a rotor composed of a rigid disk and a flexible asymmetric shaft. The general equations of motion are first derived by considering the effect of high order large deformation in bending. The equations are discretized using the Rayleigh–Ritz method. The obtained equations are nonlinear coupled differential equations that are solved using the numerical method. Sensitivity analysis has been utilized to identify the percentage of the contribution of each parameter to the increase of vibration. Then a DOE-based Response Surface Methodology (RSM) is applied to present a model to predict the vibration behavior of the system with good accuracy. Genetic algorithm is also used to optimize the effective parameters and to verify the results. A 3D model of the asymmetric rotor is carried out in experimental studies to attain more precise responses. The research shows that rotor asymmetry alone and also its combination with gravitational force has much more effects on the vibration amplitude. These effects are observed at frequencies both once and twice the rotational speed in spectral data, in comparison with other factors. The mass unbalance also plays a significant role in frequency equal to the rotational speed. In the end, the achieved results are validated with experimental simulations.

质量不平衡、轴不对中、转子不对称和转子重量引起的力是旋转机器振动的主要原因，尤其是当轴不对称时。尽管已经进行了广泛的研究来确定每个参数对振动水平增加的影响，但还没有明确研究所有这些参数的同时存在及其相互作用。在本研究中，模型是由刚性盘和柔性非对称轴组成的转子。首先通过考虑弯曲过程中高阶大变形的影响推导出一般运动方程。方程使用 Rayleigh-Ritz 方法离散化。得到的方程为非线性耦合微分方程，采用数值方法求解。灵敏度分析已被用于确定每个参数对振动增加的贡献百分比。然后应用基于 DOE 的响应面方法 (RSM) 来提供模型，以高精度预测系统的振动行为。遗传算法也用于优化有效参数并验证结果。在实验研究中进行了非对称转子的 3D 模型，以获得更精确的响应。研究表明，转子不对称本身及其与重力的结合对振动幅度的影响更大。与其他因素相比，这些效应在频谱数据中转速的一倍和两倍的频率下都可以观察到。质量不平衡在与转速相等的频率中也起着重要作用。最后，通过实验模拟验证了所取得的结果。