Exponential Softening

The Softening Law

An exponential softening law has the following values:

      [math]\displaystyle{ f(\delta,s) = f(\delta) = e^{-\delta/(sG_c)} }[/math]

      [math]\displaystyle{ A(\delta,s) = {\delta\over 2} }[/math]

where s is the softening scaling term and G_c is toughness of the law (and the law's only property). The critical crack opening displacement, which depends on mesh size and crack orientation, is given by

      [math]\displaystyle{ \delta_{max} = 2sG_c }[/math]

Softening Law Properties

Only one property is needed to define a linear softening law:

Property	Description	Units	Default
Gc	The toughness associated with the this softening law	energy release units	none

Note that softening materials