Effect of Rotor Geometry on Bending Stiffness Variation

Bending stiffness variation (BSV) is a common problem causing vibration in large rotating machinery. BSV describes lateral bending and its as function of the rotational angle. It has been observed that causes excitation exactly twice per revolution, which leads to problems, especially at half critical speed. caused by rotor geometry errors if material assumed be homogeneous linearly elastic. Therefore, study investigated with harmonic roundness components, are commonly used industry describe rotor. Hence, results easily applicable industry. The research was conducted primarily analytical means, but also static simulations numeric calculations were used. clearly showed when effect single components cross-sections observed, only second component could produce BSV. However, pairs studied, they produced without component. If included, profile most aggressively. A generated arbitrary profile, including 3–50 random phases amplitudes, indicated occurs always revolution despite different profile. improve possibilities eliminating excessive industry, certain can avoided.