Skip to content

relaxation-CSexp

Module: solid

Category: materialprop

Type string: "relaxation-CSexp"

Parameters

Name Description Default Units
tau exponential spectrum constant 0 [t]

Description

This relaxation function is derived from a continuous exponential relaxation spectrum, see FEBio Theory Manual. The material type for this relaxation function is relaxation-CSexp.

This parameter must satisfy \(\tau>0\). The reduced relaxation function for this material type is given by

\[ g\left(t\right)=2\sqrt{\frac{t}{\tau}}K_{1}\left(2\sqrt{\frac{t}{\tau}}\right) \]

where \(K_{1}\left(z\right)\) is the modified Bessel function of the second kind, of order 1.