Difference between revisions of "Exponential Softening"

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<math>f(\delta,s) = f(\delta) = e^{-\delta/(sG_c)}</math>
<math>f(\delta,s) = e^{-\delta/(sG_c)}</math>


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<math>A(\delta,s) = {\delta\over 2}</math>
<math>A(\delta,s) = cG_c - e^{-\delta/(sG_c)}\left(sG_c+{\delta\over2}\right)</math>


where s is the [[Softening Laws#Normalized Softening Law|softening scaling term]] and G<sub>c</sub> 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
where s is the [[Softening Laws#Normalized Softening Law|softening scaling term]] and G<sub>c</sub> is toughness of the law (and the law's only property). This law never fails, although the traction asymmtopically approaches zero. The exponential decay rate, $k$, is


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<math>\delta_{max} = 2sG_c</math>
<math>k = sG_c</math>


== Softening Law Properties ==
== Softening Law Properties ==


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


{| class="wikitable"
{| class="wikitable"

Revision as of 14:52, 25 December 2016

The Softening Law

An exponential softening law has the following values:

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

      [math]\displaystyle{ A(\delta,s) = cG_c - e^{-\delta/(sG_c)}\left(sG_c+{\delta\over2}\right) }[/math]

where s is the softening scaling term and Gc is toughness of the law (and the law's only property). This law never fails, although the traction asymmtopically approaches zero. The exponential decay rate, $k$, is

      [math]\displaystyle{ k = sG_c }[/math]

Softening Law Properties

Only one property is needed to define an exponential softening law:

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

Note that softening materials