Springs

Various springs are used for vibration isolation. A few of them are discussed here.

Helical spring

Helical steel springs are often used in earthquake/vibration prone areas below the superstructure. These springs offer high load bearing capacity and effective low frequency isolation. The spring constant is given as follows:

- shear modulus - wire dia - coil dia (median) - no. of coils

Performance of such springs in compression may vary significantly if the ends are not properly secured.

Transversely loaded spring

The transversely loaded arrangement as shown below offer higher load carrying capacity (due to smaller deflection). This also offers increased damping due to the friction between the spring surface and the support.

Figure 20.1: Transversely loaded spring