Question

- When a shaft is considered as an ensemble of masses, whose method is being used?

- To calculate the critical speeds using linear algebra, the relationship of force and deflection is characterized by? (form factors or influence coefficients or magnetic susceptibility or stiffness constants )

- What forces are mostly responsible for inducing vibration in rotating shafts? ( Magnetic or Viscous or Centrifugal )

Answer 1

1) Rayleigh's method is used when shaft is considered as an ensemble of masses. The shaft is divided into segments and the method gives the relationship between weight and deflection for different locations.

2) Influence coefficients. These coefficients give the relation between deflection and load at various points along the shaft

3) Centrifugal force. When the shaft rotates, any eccentricity in mass increases the outward force (Centrifugal force) and thus causes the shaft to vibrate.

Hope it helps.