Method of Analysis of Machine Foundation

There are various methods of analysis for machine foundation. They include:Empirical methods Elastic half space method Lumped parameter method Barkan's methodAmong these methods lumped parameter method and barkan's method are most popular widely used.Empirical methods: -  The empirical methods suggested by Tschebotarioff and Alpan can be used for preliminary design purpose for the different soil types. However, these methods can Read more [...]

Forced Frequency Dependent Exciting Force with Viscous Damping

Some machines like Turbo-generators produce unbalanced force which imparts into the foundation-soil system frequency dependent exciting force. In Turbo generators two counteracting masses are placed at an eccentricity, e. This is shown in Figs. 1(a) and (b).The masses are so placed that they reach the top simultaneously. The rotating force of each mass is given by, ----------(1)Referring to the figure and resolving the force horizontally Read more [...]

Forced Vibration of a Mass Spring System with Damping

In foundation soil system damping is always present in one form or another. For this case fig. 1 (a), the equation of motion is:  ----------(1)  ----------(2)The solution of equation (2) is done by applying the concept of rotating vector. In the figure 1 the exciting force vector Q ­ ­ ­0 is placed with a phase angle ɸ ahead of the displacement vector A. The equation of displacement may be expressed as:  ----------(3)In Read more [...]

Forced Vibration of a Mass Spring System without Damping

In the case forced vibration of a mass spring system without damping the mass spring system is acted by a periodic oscillation force and the damping is absent. Unbalanced rotating machinery such as compressor piston produces such type of motion. This is shown in fig.1 (a). For this case the equation of motion can be written as:----------(1)The solution of equation includes the solution for free vibration and solution satisfying the right Read more [...]

Free Vibration of a Mass Spring System with Damping

Fíg.1 (a) shows the free vibration of a system with damping. A device known as damper is shown in the figure below.The damping force acts in the opposite direction to that of oscillating mass. The equation of motion for this case can be written as:  ----------(1)Where, c = coefficient of viscous dampingOr,   ----------(2) Or,   ----------(3) Put then   And   ----------(4)By Read more [...]