Pressure Traction Law - Revision history

Nairnj: /* Traction Law Properties */

2023-11-14T22:55:11Z

Traction Law Properties

← Older revision		Revision as of 22:55, 14 November 2023
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	\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|pressure units]] \|\| none		\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|pressure units]] \|\| none
	\|-		\|-
	\| minCOD \|\| Specify a minimum, normal, crack opening displacement below which no pressure is applied. This parameter can model pressure induced by a substance that needs room to enter the crack~~; it is ignored if it is~~ negative (or omitted) \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|length units]] \|\| -1		\| minCOD \|\| Specify a minimum, normal, crack opening displacement (COD) below which no pressure is applied. This parameter can model pressure induced by a substance that needs room to enter the crack. If negative (or omitted), the pressure is applied for all CODs. \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|length units]] \|\| -1
	\|}		\|}

Nairnj: /* Traction Law Properties */

2023-03-20T02:58:39Z

Traction Law Properties

← Older revision		Revision as of 02:58, 20 March 2023
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	\|}		\|}

	If a function is used, any entered stress property is ignored. If <~~code~~>minCOD</~~code~~> is used and no other boundary conditions cause the crack to open, the crack will never see any pressure.		If a function is used, any entered stress property is ignored. If <tt>minCOD</tt> is used and no other boundary conditions cause the crack to open, the crack will never see any pressure.

	== Traction History Variables ==		== Traction History Variables ==

	This material tracks no history variables.		This material tracks no history variables.

Nairnj: /* Traction Law Properties */

2023-03-20T02:58:28Z

Traction Law Properties

← Older revision		Revision as of 02:58, 20 March 2023
Line 25:		Line 25:
	\|}		\|}

	If a function is used, any entered stress property is ignored. If <tt>minCOD</tt> is used and no other boundary conditions cause the crack to open, the crack will never see any pressure.		If a function is used, any entered stress property is ignored. If <code>minCOD</code> is used and no other boundary conditions cause the crack to open, the crack will never see any pressure.

	== Traction History Variables ==		== Traction History Variables ==

	This material tracks no history variables.		This material tracks no history variables.

Nairnj: /* Traction Law Properties */

2023-03-20T02:57:58Z

Traction Law Properties

← Older revision		Revision as of 02:57, 20 March 2023
Line 25:		Line 25:
	\|}		\|}

	If a function is used, any entered stress property is ignored.		If a function is used, any entered stress property is ignored. If <tt>minCOD</tt> is used and no other boundary conditions cause the crack to open, the crack will never see any pressure.

	== Traction History Variables ==		== Traction History Variables ==

	This material tracks no history variables.		This material tracks no history variables.

Nairnj: /* Traction Law Properties */

2023-03-20T02:56:34Z

Traction Law Properties

← Older revision		Revision as of 02:56, 20 March 2023
Line 22:		Line 22:
	\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|pressure units]] \|\| none		\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|pressure units]] \|\| none
	\|-		\|-
	\| minCOD \|\| Specify a minimum, normal, crack opening displacement below which no pressure is applied. This parameter can model pressure induced by a substance that needs room to enter the crack; it is ignored if it is negative \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|length units]] \|\| -1		\| minCOD \|\| Specify a minimum, normal, crack opening displacement below which no pressure is applied. This parameter can model pressure induced by a substance that needs room to enter the crack; it is ignored if it is negative (or omitted) \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|length units]] \|\| -1
	\|}		\|}

Nairnj: /* Traction Law Properties */

2021-01-03T05:31:26Z

Traction Law Properties

← Older revision		Revision as of 05:31, 3 January 2021
Line 26:		Line 26:

	If a function is used, any entered stress property is ignored.		If a function is used, any entered stress property is ignored.

			== Traction History Variables ==

			This material tracks no history variables.

Nairnj: /* The Traction Law */

2017-04-14T16:44:55Z

The Traction Law

← Older revision		Revision as of 16:44, 14 April 2017
Line 4:		Line 4:
	This [[Traction Laws\|traction law]] applies a constant stress that is normal to the crack surface. It can be used to model a pressure-loaded crack. The stress can be entered in one of two ways:		This [[Traction Laws\|traction law]] applies a constant stress that is normal to the crack surface. It can be used to model a pressure-loaded crack. The stress can be entered in one of two ways:

	You can either apply a constant stress or provide a [[User Defined Functions\|user-defined function]] to let the stress vary in time. Even if you want a constant stress, experience shows that applying that full stress from the start of calculation ~~can~~ cause ~~large,~~ local vibrations and ~~lead to unstable~~ results. If it ~~usually~~ better to ramp the stress up to the constant stress by applying an appropriate ramping [[User Defined Functions\|function]].		You can either apply a constant stress or provide a [[User Defined Functions\|user-defined function]] to let the stress vary in time. Even if you want a constant stress, experience shows that applying that full stress from the start of calculation may cause local vibrations and less stable results. If it often better to ramp the stress up to the constant stress by applying an appropriate ramping [[User Defined Functions\|function]].

	== Failure ==		== Failure ==

Nairnj at 21:48, 2 June 2015

2015-06-02T21:48:53Z

← Older revision		Revision as of 21:48, 2 June 2015
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	! Property !! Description !! Units !! Default		! Property !! Description !! Units !! Default
	\|-		\|-
	\| stress \|\| Enter constant normal stress. Use negative stress for a pressure loaded crack.\|\| ~~MPa~~ \|\| none		\| stress \|\| Enter constant normal stress. Use negative stress for a pressure loaded crack.\|\| [[ConsistentUnits Command#Legacy and Consistent Units\|pressure units]] \|\| none
	\|-		\|-
	\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| ~~MPM~~ \|\| none		\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|pressure units]] \|\| none
	\|-		\|-
	\| minCOD \|\| Specify a minimum, normal, crack opening displacement below which no pressure is applied. This parameter can model pressure induced by a substance that needs room to enter the crack; it is ignored if it is negative \|\| mm \|\| -1		\| minCOD \|\| Specify a minimum, normal, crack opening displacement below which no pressure is applied. This parameter can model pressure induced by a substance that needs room to enter the crack; it is ignored if it is negative \|\| [[ConsistentUnits Command#Legacy and Consistent Units\|length units]] \|\| -1
	\|}		\|}

	If a function is used, any entered stress property is ignored.		If a function is used, any entered stress property is ignored.

Nairnj: /* Traction Law Properties */

2014-11-13T18:08:25Z

Traction Law Properties

← Older revision		Revision as of 18:08, 13 November 2014
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	\|-		\|-
	\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| MPM \|\| none		\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| MPM \|\| none
			\|-
			\| minCOD \|\| Specify a minimum, normal, crack opening displacement below which no pressure is applied. This parameter can model pressure induced by a substance that needs room to enter the crack; it is ignored if it is negative \|\| mm \|\| -1
	\|}		\|}

	If a function is used, any entered stress property is ignored.		If a function is used, any entered stress property is ignored.

Nairnj at 15:54, 8 January 2014

2014-01-08T15:54:19Z

← Older revision		Revision as of 15:54, 8 January 2014
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	~~<p>This traction law creates a constant stress that is normal to the crack surface. It models a pressure loaded crack.~~ The ~~stress can be entered in one of two ways:~~		__TOC__
	~~</p>~~		== The Traction Law ==

	~~<ul>~~		This [[Traction Laws\|traction law]] applies a constant stress that is normal to the crack surface. It can be used to model a pressure-loaded crack. The stress can be entered in one of two ways:

	~~<li><code>~~stress~~</code>~~ - ~~Enter~~ constant ~~normal~~ stress ~~(in MPa)~~. ~~Use negative~~ stress ~~for a pressure loaded crack~~.~~</li>~~		You can either apply a constant stress or provide a [[User Defined Functions\|user-defined function]] to let the stress vary in time. Even if you want a constant stress, experience shows that applying that full stress from the start of calculation can cause large, local vibrations and lead to unstable results. If it usually better to ramp the stress up to the constant stress by applying an appropriate ramping [[User Defined Functions\|function]].

	~~<li><code>function</code> - alternatively, the stress can be entered as a <a href~~=~~"function.html">user-defined function</a> of time (giving stress in MPa). If a function is used, any entered <code>stress</code> property is ignored.</li>~~		== Failure ==

	~~</ul>~~		This traction does not fail; it just continues to apply normal stress. By using a [[User Defined Functions\|function]], the stress can be time dependent.

	~~Experience shows that apply full~~ stress ~~from~~ the ~~start~~ of ~~calculation can cause large, local vibrations and lead to unstable results~~. If ~~it often better to use the <code>~~function~~</code> option and ramp the~~ stress ~~to desired value~~.		== Traction Law Properties ==

			The following properties are used to create a pressure traction law:

			{\| class="wikitable"
			\|-
			! Property !! Description !! Units !! Default
			\|-
			\| stress \|\| Enter constant normal stress. Use negative stress for a pressure loaded crack.\|\| MPa \|\| none
			\|-
			\| function \|\| Alternatively, the stress can be entered as a [[User Defined Functions\|user-defined function]] of time. \|\| MPM \|\| none
			\|}

			If a function is used, any entered stress property is ignored.