Difference between revisions of "PointList Block"

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A <tt><PointList></tt> block can explicitly list individual material points.
A <tt><PointList></tt> block can explicitly list individual material points. This block is almost never used because it is much better to use [[MPM Region and Hole Commands|<tt>Region</tt> and <tt>Hole</tt> commands]]. The one exception is when running a calculation based on [[Reading Material Points from a Previous Simulation|material point locations from a previous simulation]].


== PointList Block ==
== PointList Block ==
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  <PointList>
  <PointList>
   <mp elem='(elemNum)' mat='(natNum)' angle='(angle)' thick='(thick)' conc='(conc)' temp='(temp)'>
   <mp elem='(elemNum)' mat='(natNum)' angle='(angle)' thick='(thick)' conc='(conc)' temp='(temp)'>
     <pt units='mm' x='1.25' y='-11.25'/>
     <pt x='1.25' y='-11.25'/>
     <vel units='mm/sec' x='0' y='0'/>
     <vel x='0' y='0'/>
    <mass m='1e-3'/>
   </mp>
   </mp>
     . . .
     . . .
Line 18: Line 19:
* <tt>(matNum)</tt> - the material nuimber (a number can be replaced by a material name using a <tt>matname</tt> attribute as explained [[Material Command Block#Referencing Materials in XML Files|here]].
* <tt>(matNum)</tt> - the material nuimber (a number can be replaced by a material name using a <tt>matname</tt> attribute as explained [[Material Command Block#Referencing Materials in XML Files|here]].
* <tt>(angle)</tt> - the material angle (in degrees) which is used for some [[Material Models|anisotropic materials]] (default = 0).
* <tt>(angle)</tt> - the material angle (in degrees) which is used for some [[Material Models|anisotropic materials]] (default = 0).
* <tt>(thick)</tt> - the thickness (in mm), for planar 2D only.
* <tt>(thick)</tt> - the thickness (in [[ConsistentUnits Command#Legacy and Consistent Units|length units]]), for planar 2D only (default is equal to the [[MPM Grid Generation|grid thickness]]).
* <tt>(conc)</tt> - the initial concentration (set as potential from 0 to 1 where 1 is the saturation concentration for the particle's material type) when doing [[Diffusion Calculations|diffusion calculations]]. Alternatively you can set initial concentration as weight fraction by using a <tt>wtconc</tt> attribute instead. The weight fraction concentration must be between 0 and the saturation concentration for the particle's material type. If both <tt>conc</tt> and <tt>conc</tt> are used, the one that appears last will determine the concentration.
* <tt>(conc)</tt> - the initial concentration (set as potential from 0 to 1 where 1 is the saturation concentration for the particle's material type) when doing [[Diffusion Calculations|diffusion calculations]]. Alternatively you can set initial concentration as weight fraction by using a <tt>wtconc</tt> attribute instead. The weight fraction concentration must be between 0 and the saturation concentration for the particle's material type. If both <tt>conc</tt> and <tt>conc</tt> are used, the one that appears last will determine the concentration (default 0).
* <tt>(temp)</tt> - the initial temperature (temp) when doing thermal loading or conduction calculations.
* <tt>(temp)</tt> - the initial temperature (temp) when doing [[Thermal Calculations|thermal loading or conduction calculations]] (default is the [[Thermal Calculations#Stress Free Temperature|stress free temperature]]).


The elements subordinate to <mp> define the material point location (<pt> and its (x, y, (z if 3D)) coordinates in attributes in mm, but an optional units attribute can specify other length units) and the material point's initial velocity (<vel> and the velocity in the x, y, and z (if 3D) directions in mm/sec, but an optional units attribute can specify other velocity units). If not specified, the initial velocity, angle, and concentration potential will all be zero, the thickness (if planar 2D) will be the grid thickness, and the temperature will be equal to the stress-free temperature. For axisymmetric calculations use x and y to enter R and Z coordinates.
Subordinate to each <tt><mp></tt> element, you define the material point properties using <tt><pt></tt> (required), <tt><vel></tt>, and <tt><mass></tt> commands:


Normally the particle mass is determined from the size of the elements and the number of particles per element. When running a simulation based on material points from a previous simulation, a subordinate <mass> element can be used to set the particle mass (in g, but an optional units attribute can specify the mass units).
* <tt><pt></tt> - gives the x, y, and z (if 3D)) coordinates in attributes in [[ConsistentUnits Command#Legacy and Consistent Units|length units]] and this element is required (if using Legacy units where coordinates units are in mm, an optional [[Units Attribute|units attribute]] can specify other length units).
* <tt><vel></tt> - give the material point's initial velocity in the x, y, and z (if 3D) directions in [[ConsistentUnits Command#Legacy and Consistent Units|velocity units]] (if using Legacy units where velocity units are in mm/s, an optional [[Units Attribute|units attribute]] can specify other velocity units). If omitted, velocity is set to zero.
* <tt><mass></tt> - normally the particle mass is determined from the size of the elements and the number of particles per element and this command is not used. When running a simulation based on material points from a previous simulation, this command can be used to set the particle mass in [[ConsistentUnits Command#Legacy and Consistent Units|mass units]] (if using Legacy units where mass units are in g, an optional [[Units Attribute|units attribute]] can specify other mass units).

Latest revision as of 14:06, 13 December 2019

A <PointList> block can explicitly list individual material points. This block is almost never used because it is much better to use Region and Hole commands. The one exception is when running a calculation based on material point locations from a previous simulation.

PointList Block

An XML file can include one <PointList> block and it must be within the single<MaterialPoints>.

<PointList>
  <mp elem='(elemNum)' mat='(natNum)' angle='(angle)' thick='(thick)' conc='(conc)' temp='(temp)'>
    <pt x='1.25' y='-11.25'/>
    <vel x='0' y='0'/>
    <mass m='1e-3'/>
  </mp>
   . . .
</PointList>

Within the <PointList> block,the material points are defined by a series of subordinate <mp> elements. Its attributes are:

  • (elemNum) - the element number that contains the material point (this attribute is optional; if not provided the element will be looked up)
  • (matNum) - the material nuimber (a number can be replaced by a material name using a matname attribute as explained here.
  • (angle) - the material angle (in degrees) which is used for some anisotropic materials (default = 0).
  • (thick) - the thickness (in length units), for planar 2D only (default is equal to the grid thickness).
  • (conc) - the initial concentration (set as potential from 0 to 1 where 1 is the saturation concentration for the particle's material type) when doing diffusion calculations. Alternatively you can set initial concentration as weight fraction by using a wtconc attribute instead. The weight fraction concentration must be between 0 and the saturation concentration for the particle's material type. If both conc and conc are used, the one that appears last will determine the concentration (default 0).
  • (temp) - the initial temperature (temp) when doing thermal loading or conduction calculations (default is the stress free temperature).

Subordinate to each <mp> element, you define the material point properties using <pt> (required), <vel>, and <mass> commands:

  • <pt> - gives the x, y, and z (if 3D)) coordinates in attributes in length units and this element is required (if using Legacy units where coordinates units are in mm, an optional units attribute can specify other length units).
  • <vel> - give the material point's initial velocity in the x, y, and z (if 3D) directions in velocity units (if using Legacy units where velocity units are in mm/s, an optional units attribute can specify other velocity units). If omitted, velocity is set to zero.
  • <mass> - normally the particle mass is determined from the size of the elements and the number of particles per element and this command is not used. When running a simulation based on material points from a previous simulation, this command can be used to set the particle mass in mass units (if using Legacy units where mass units are in g, an optional units attribute can specify other mass units).