In physics, damping is any effect that tends to reduce the amplitude of oscillations in an oscillatory system. These Excel worksheets have been supplied by the visionary ExcelCalcs user George Lungu. They allow you to interact with a live animated oscillator to investigate the effects of changes to mass, stiffness and damping.
Watch these videos: Spring Damper 1DOF Demonstration and Spring Damper 1DOF Explained  
In mechanics, friction is one such damping effect. For many purposes
the frictional force F can be modelled as being proportional to the
velocity v of the object.
The value of the damping ratio ζ critically
determines the behaviour of the system. A damped harmonic oscillator can
be: * Overdamped (ζ > 1): The system returns (exponentially decays) to equilibrium without oscillating. Larger values of the damping ratio ζ return to equilibrium slower. * Critically damped (ζ = 1): The system returns to equilibrium as quickly as possible without oscillating. This is often desired for the damping of systems such as doors. * Underdamped (ζ < 1): The system oscillates (with a slightly different frequency than the undamped case) with the amplitude gradually decreasing to zero. 

Two degrees of freedom means that two is the minimum number of coordinates necessary to uniquely specify the position of the system. Study the properties of linear vibrating systems with two degreesoffreedom. If you have already seen the one degreeoffreedom vibrating system (the massspringdashpot system) then you will have some familiarity with natural frequency and resonance. It is a very useful worksheet to investigate tuned absorbers/dampers. These are reactive devices used in structural (and acoustic) systems to either absorb oscillation at a certain forcing frequency or damp oscillation at a particular resonant frequency. You can download it here: Spring Damper 2DOF.xls 

Tripple Spring Damper Demonstration  
One mass and three spring dampers are used to create and Excel spirograph. Its an impressive demonstration of Excel used as a simulation tool. It can be downloaded here: Tripple Spring Damper.xls 
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