- #1
muzialis
- 166
- 1
Hi there,
I came across the concept of Rayleigh damping. I aqm told it is unrelated to viscoelasticity and as a result is unable to reproduce the behaviour of real materials under harmonic excitation.
I can not understand why.
Considering for simplicity a 1D setting, a ball of mass $$M$$ linked to a rigid wall by a spring of elastic constant $$K$$. Rayleigh damping dictates to model losses via a matrix (in our case, a scalar) given by $$D = \alpha M + \beta K$$.
The motion of the ball under an applied harmonic force is represented by the solution of the ODE
$$M\ddot{x}+D\dot{x}+Kx = F_0 cos(\omega t)$$.
Well it seems to be that this is analogous to considering the material as a Kelvin-type (spring and Newtonian dampener in parallel) viscoelastic one. Not the best representation for real materials, but not too bad in some instances. Is all this correct?
Thanks
I came across the concept of Rayleigh damping. I aqm told it is unrelated to viscoelasticity and as a result is unable to reproduce the behaviour of real materials under harmonic excitation.
I can not understand why.
Considering for simplicity a 1D setting, a ball of mass $$M$$ linked to a rigid wall by a spring of elastic constant $$K$$. Rayleigh damping dictates to model losses via a matrix (in our case, a scalar) given by $$D = \alpha M + \beta K$$.
The motion of the ball under an applied harmonic force is represented by the solution of the ODE
$$M\ddot{x}+D\dot{x}+Kx = F_0 cos(\omega t)$$.
Well it seems to be that this is analogous to considering the material as a Kelvin-type (spring and Newtonian dampener in parallel) viscoelastic one. Not the best representation for real materials, but not too bad in some instances. Is all this correct?
Thanks