3D Cracks - Revision history

Nairnj at 21:51, 26 April 2024

2024-04-26T21:51:48Z

← Older revision		Revision as of 21:51, 26 April 2024
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	3D cracks are currently in development and available only in [[OSParticulas]]. This page explains how to add them to 3D MPM simulations. 3D cracks are ~~modeling~~ but do not yet have 3D J integral or have any options for crack propagation. You can, however, add [[Traction Laws\|traction laws]] to model crack-tip cohesive zones. Failure of ~~tractions~~ is ~~one option~~ to ~~model~~ 3D crack propagation.		3D cracks are currently in development and available only in [[OSParticulas]]. This page explains how to add them to 3D MPM simulations. Explicit 3D cracks are modeled well, but do not yet have 3D J integral or have any options for explicit crack propagation. You can, however, add [[Traction Laws\|traction laws]] to model crack-tip cohesive zones. Failure of cohesive zones is an alternative approach to modeling 3D crack propagation.
	__TOC__		__TOC__
	== Introduction ==		== Introduction ==

Nairnj at 21:45, 26 April 2024

2024-04-26T21:45:20Z

← Older revision		Revision as of 21:45, 26 April 2024
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	3D cracks are currently in development and available only in [[OSParticulas]]. This page explains how to add them to 3D MPM simulations.		3D cracks are currently in development and available only in [[OSParticulas]]. This page explains how to add them to 3D MPM simulations. 3D cracks are modeling but do not yet have 3D J integral or have any options for crack propagation. You can, however, add [[Traction Laws\|traction laws]] to model crack-tip cohesive zones. Failure of tractions is one option to model 3D crack propagation.
	__TOC__		__TOC__
	== Introduction ==		== Introduction ==

Nairnj: /* General 3D Crack Definition */

2022-08-01T21:42:45Z

General 3D Crack Definition

← Older revision		Revision as of 21:42, 1 August 2022
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	# If a facet has a cohesive zone, all crack particles in that facet will be assigned to that cohesive zone. If one of the edges of that facet is shared with another facet, two possibilities arise:		# If a facet has a cohesive zone, all crack particles in that facet will be assigned to that cohesive zone. If one of the edges of that facet is shared with another facet, two possibilities arise:
	## If the other facet does not have a cohesive zone, the crack particles on the shared edge will use the cohesive zone		## If the other facet does not have a cohesive zone, the crack particles on the shared edge will use the cohesive zone
	## If two facets with different cohesive ~~zone~~ share ~~and~~ edge, the crack ~~particle~~ on the shared edge will used the cohesive zone assigned to the second facet with that edge.		## If two facets with different cohesive zones share an edge, the crack particles on the shared edge will used the cohesive zone assigned to the second facet with that edge.

Nairnj: /* General 3D Crack Definition */

2022-08-01T21:41:28Z

General 3D Crack Definition

← Older revision		Revision as of 21:41, 1 August 2022
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	# The crack mesh must use all defined key points. An error occurs if any are left unused.		# The crack mesh must use all defined key points. An error occurs if any are left unused.
	# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).		# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).
	# If a facet has a cohesive zone, all crack particles in that facet will be assigned to that cohesive zone. If ~~you~~ of the edges of that facet is shared with another facet, two possibilities arise:		# If a facet has a cohesive zone, all crack particles in that facet will be assigned to that cohesive zone. If one of the edges of that facet is shared with another facet, two possibilities arise:
	## If the other facet does not have a cohesive zone, the ~~particle~~ on the shared edge will use the cohesive zone		## If the other facet does not have a cohesive zone, the crack particles on the shared edge will use the cohesive zone
	## If ~~the other facet uses a~~ different cohesive zone, the particle on the shared edge will used the cohesive zone ~~used for~~ the second facet with that edge.		## If two facets with different cohesive zone share and edge, the crack particle on the shared edge will used the cohesive zone assigned to the second facet with that edge.

Nairnj: /* General 3D Crack Definition */

2022-08-01T21:40:04Z

General 3D Crack Definition

← Older revision		Revision as of 21:40, 1 August 2022
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	# The crack mesh must use all defined key points. An error occurs if any are left unused.		# The crack mesh must use all defined key points. An error occurs if any are left unused.
	# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).		# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).
			# If a facet has a cohesive zone, all crack particles in that facet will be assigned to that cohesive zone. If you of the edges of that facet is shared with another facet, two possibilities arise:
			## If the other facet does not have a cohesive zone, the particle on the shared edge will use the cohesive zone
			## If the other facet uses a different cohesive zone, the particle on the shared edge will used the cohesive zone used for the second facet with that edge.

Nairnj: /* General 3D Crack Definition */

2022-01-30T18:24:33Z

General 3D Crack Definition

← Older revision		Revision as of 18:24, 30 January 2022
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	...		...

	In XML files, each arbitrary crack is defined with one <tt><Mesh></tt> block within a <tt><CrackList></tt> block:		In XML files, each arbitrary crack is defined with one and only one <tt><Mesh></tt> block within a <tt><CrackList></tt> block:

	<CrackList law='(lawnum)' lawname='(lawname)'>		<CrackList law='(lawnum)' lawname='(lawname)'>
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	# The crack mesh must use all defined key points. An error occurs if any are left unused.		# The crack mesh must use all defined key points. An error occurs if any are left unused.
	# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).		# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).
	~~# In XML files, each <tt><CrackList></tt> block can have only one <tt><Mesh></tt> block.~~

Nairnj: /* General 3D Crack Definition */

2022-01-30T18:23:45Z

General 3D Crack Definition

← Older revision		Revision as of 18:23, 30 January 2022
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	# Crack meshes may deviate from the entered <tt>(length)</tt> to get better proportioned elements.		# Crack meshes may deviate from the entered <tt>(length)</tt> to get better proportioned elements.
	# Crack meshes work best if the facets used to create the crack are similarly sized. If different sizes are needed, it is best to start with the largest ones.		# Crack meshes work best if the facets used to create the crack are similarly sized. If different sizes are needed, it is best to start with the largest ones.
	# The code to optimize cracks works best if each new facet has two new edges. If needed, a facet with only one new edge is allowed. Except for the first facet, added facets should have three new edges		# The code to optimize cracks works best if each new facet has two new edges. If needed, a facet with only one new edge is allowed. Except for the first facet, added facets should never have three new edges; in other words, each added facet should be connected to one (or two) previous facets.
	# The crack mesh must use all defined key points. An error occurs if any are left unused.		# The crack mesh must use all defined key points. An error occurs if any are left unused.
	# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).		# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).
	# In XML files, each <tt><CrackList></tt> block can have only one <tt><Mesh></tt> block.		# In XML files, each <tt><CrackList></tt> block can have only one <tt><Mesh></tt> block.

Nairnj: /* General 3D Crack Definition */

2022-01-30T18:22:08Z

General 3D Crack Definition

← Older revision		Revision as of 18:22, 30 January 2022
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	# Crack meshes may deviate from the entered <tt>(length)</tt> to get better proportioned elements.		# Crack meshes may deviate from the entered <tt>(length)</tt> to get better proportioned elements.
	# Crack meshes work best if ~~defined~~ facets are similarly sized. If different sizes ~~facets~~ are ~~used~~, it is best to start with the largest ones.		# Crack meshes work best if the facets used to create the crack are similarly sized. If different sizes are needed, it is best to start with the largest ones.
	# The code to optimize cracks works best if each new facet has two new edges. If needed, a facet with only one new edge is allowed. Except for the first facet, added facets should have three new edges		# The code to optimize cracks works best if each new facet has two new edges. If needed, a facet with only one new edge is allowed. Except for the first facet, added facets should have three new edges
	# The crack mesh must use all defined key points. An error occurs if any are left unused.		# The crack mesh must use all defined key points. An error occurs if any are left unused.
	# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).		# No edge connecting two key points can be used in more than two facets (''i.e.'', an edge can only be shared by two facets).
	# In XML files, each <tt><CrackList></tt> block can have only one <tt><Mesh></tt> block.		# In XML files, each <tt><CrackList></tt> block can have only one <tt><Mesh></tt> block.

Nairnj: /* General 3D Crack Definition */

2022-01-30T18:21:13Z

General 3D Crack Definition

← Older revision		Revision as of 18:21, 30 January 2022
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	* <tt>(czm)</tt> (or <tt>(czmname)</tt>) - all facets created can optionally be assigned a [[Traction Laws\|traction law]]. Scripted files choose the law by material ID. In XML files, you specify an optional [[Traction Laws\|traction law]] by number in <tt>(czm)</tt> or by name in <tt>(czmname)</tt>. If both are used, the name takes precedence.		* <tt>(czm)</tt> (or <tt>(czmname)</tt>) - all facets created can optionally be assigned a [[Traction Laws\|traction law]]. Scripted files choose the law by material ID. In XML files, you specify an optional [[Traction Laws\|traction law]] by number in <tt>(czm)</tt> or by name in <tt>(czmname)</tt>. If both are used, the name takes precedence.

	Some notes on defining 3D cracks as as follows:		Some notes on defining 3D cracks are as follows:

	# Crack meshes may deviate from the entered <tt>(length)</tt> to get better proportioned elements.		# Crack meshes may deviate from the entered <tt>(length)</tt> to get better proportioned elements.

Nairnj: /* General 3D Crack Definition */

2022-01-30T18:19:16Z

General 3D Crack Definition

← Older revision		Revision as of 18:19, 30 January 2022
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	* (lawID)</tt> (and <tt>(lawnum)</tt>) - this parameter customizes this crack to use a different [[Contact Laws\|contact law]] for modeling crack contact (''i.e.'', a different [[Contact Laws\|contact law]] or [[Imperfect Interfaces#Imperfect Interfaces on Explicit Cracks\|imperfect interface]] for this crack than the one selected by the [[Friction#Friction on Explicit Cracks\|global <tt>ContactCracks</tt> command]]). In XML files, the custom [[Contact Laws\|contact law]] can be specified by number or name (in <tt>(lawnum)</tt> or <tt>(lawname)</tt>). If both are used, the name takes precedence.		* (lawID)</tt> (and <tt>(lawnum)</tt>) - this parameter customizes this crack to use a different [[Contact Laws\|contact law]] for modeling crack contact (''i.e.'', a different [[Contact Laws\|contact law]] or [[Imperfect Interfaces#Imperfect Interfaces on Explicit Cracks\|imperfect interface]] for this crack than the one selected by the [[Friction#Friction on Explicit Cracks\|global <tt>ContactCracks</tt> command]]). In XML files, the custom [[Contact Laws\|contact law]] can be specified by number or name (in <tt>(lawnum)</tt> or <tt>(lawname)</tt>). If both are used, the name takes precedence.

	The subsequent commands for both scripted files and XML files define a collection of crack points or nodes on the crack surface with coordinates <tt>((x),(y),(z))</tt>. In scripted files, each key point is assigned an <tt>(id)</tt>, which can be any string. In XML files, key points implicitly numbered by order in the <tt><NodeList></tt> block starting at 1.		The subsequent commands for both scripted files and XML files define a collection of crack points or nodes on the crack surface with coordinates <tt>((x),(y),(z))</tt>. In scripted files, each key point is assigned an <tt>(id)</tt>, which can be any string. In XML files, key points are implicitly numbered by order in the <tt><NodeList></tt> block starting at 1.

	Once the key points are defined, they are connected by triangular facets. Scripted files use CrackFacet commands where <tt>(id1),(id2),(id3)</tt> specify three key points using their IDs. XML files use <tt><elem></tt> commands where <tt>(nd1),(nd2),(nd3)</tt> specify three key points by number in the <tt><NodeList></tt> block. The two remaining parameters are:		Once the key points are defined, they are connected by triangular facets. Scripted files use CrackFacet commands where <tt>(id1),(id2),(id3)</tt> specify three key points using their IDs. XML files use <tt><elem></tt> commands where <tt>(nd1),(nd2),(nd3)</tt> specify three key points by number in the <tt><NodeList></tt> block. The two remaining parameters are: