Kelvin-Voigt model
= Kelvin-Voigt model
{c}
{title2=$F=kx+\mu\dot x$}
The <Kelvin-Voigt model> puts a spring and dashpot in parallel. Their common displacement makes their forces add. With the convention $e^{i\omega t}$, the complex stiffness is $k+i\omega\mu$, giving storage stiffness $k$ and loss stiffness $\omega\mu$. Under a force step, $x=(F_0/k)(1-e^{-t/\tau})$ with $\tau=\mu/k$. The series spring–dashpot is a <Maxwell fluid> analogue and has different relaxation and creep behavior.