measuring damping coeficient

Assuming it's a "nice" material with a near-constant spring constant, you should be able to just set it vibrating and measure the natural decay of the vibration amplitude...you can back out the damping coefficient from that data.

Tom.

Thanx for the reply.But I dont understand what you mean.Could please explain further.I let it vibrate & do I measure the time it takes to settle

Don't measure the time it takes to settle, just get a plot (table, whatever) of the positition vs. time for the naturally vibrating system. Or, you can do a forced vibration and measure the phase and amplitude difference between the forcing function and the actual position.

Either way, from that data you can determine the constants in the position vs. time differential equation for simple harmonic motion (see

Once you know the constants, you can calculate the damping coefficient.

Tom.