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SolidFixedCondition[pred,vars,pars]

represents a fully constrained solid boundary for PDEs with predicate pred indicating where it applies, with model variables vars and global parameters pars.

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SolidFixedCondition

SolidFixedCondition[pred,vars,pars]

represents a fully constrained solid boundary for PDEs with predicate pred indicating where it applies, with model variables vars and global parameters pars.

Details

  • SolidFixedCondition specifies a boundary condition for SolidMechanicsPDEComponent.
  • SolidFixedCondition is also known as a fixed support boundary condition.
  • SolidFixedCondition is typically used to fully constrain the movement of a solid boundary. Common examples include a beam that is fixed to a wall at one side.
  • SolidFixedCondition constrains the movement of a solid with dependent variables , and , independent variables and time variable .
  • Stationary variables vars are vars={{u[x1,…,xn],v[x1,…,xn],…},{x1,…,xn}}.
  • Time-dependent variables vars are vars={{u[t,x1,…,xn],v[t,x1,…,xn],…},t,{x1,…,xn}}.
  • Frequency-dependent variables vars are vars={{u[x1,…,xn],v[x1,…,xn],…},ω,{x1,…,xn}}.
  • The fixed constraint SolidFixedCondition models , and .
  • SolidFixedCondition is a special case of SolidDisplacementCondition where the displacements are set to 0.
  • Model parameters pars are specified as for SolidMechanicsPDEComponent.
  • A fixed condition boundary can be used with:
  • analysis typeapplicable
    TransientYes
    Frequency ResponseYes
    EigenfrequencyYes
    StationaryYes
  • SolidFixedCondition evaluates to a DirichletCondition.
  • The boundary predicate pred can be specified as in DirichletCondition.
  • If the SolidFixedCondition depends on parameters that are specified in the association pars as …,keypi…,pivi,…, the parameters are replaced with .

Examples

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Basic Examples  (1)

Compute the deflection of a spoon held fixed at the end and with a force applied at the top. Set up variables and parameters:

Wolfram Language code: vars = {{u[x, y, z], v[x, y, z], w[x, y, z]}, {x, y, z}}; pars = <|"Material" -> ["Silver"]|>;

Set up the PDE and the geometry:

Wolfram Language code: spoon = \!\(\*Graphics3DBox[«5»]\); displacement = NDSolveValue[{SolidMechanicsPDEComponent[vars, pars] == SolidBoundaryLoadValue[x >= 1 / 10, vars, pars, <|"Force" -> {0, 0, Quantity[-100, "Newtons"]}|>], SolidFixedCondition[x <= -1 / 10, vars, pars]}, {u[x, y, z], v[x, y, z], w[x, y, z]}, {x, y, z}∈spoon];

Visualize the displacement:

Wolfram Language code: VectorDisplacementPlot3D[displacement, {x, y, z}∈spoon]

Properties & Relations  (2)

SolidFixedCondition evaluates to DirichletCondition:

Wolfram Language code: SolidFixedCondition[x == 0, {{u[x, y, z], v[x, y, z], w[x, y, z]}, {x, y, z}}, <||>]

SolidFixedCondition is a special case of SolidDisplacementCondition. Set up variables and parameters:

Wolfram Language code: vars = {{u[x, y, z], v[x, y, z], w[x, y, z]}, {x, y, z}};

Create a fixed constraint:

Wolfram Language code: SolidFixedCondition[x == 0, vars, <||>]

This is the same as a displacement condition with 0 displacement:

Wolfram Language code: SolidDisplacementCondition[x == 0, vars, <||>, <|"Displacement" -> {0, 0, 0}|>]
Wolfram Research (2021), SolidFixedCondition, Wolfram Language function, https://reference.wolfram.com/language/ref/SolidFixedCondition.html.

Text

Wolfram Research (2021), SolidFixedCondition, Wolfram Language function, https://reference.wolfram.com/language/ref/SolidFixedCondition.html.

CMS

Wolfram Language. 2021. "SolidFixedCondition." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/SolidFixedCondition.html.

APA

Wolfram Language. (2021). SolidFixedCondition. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/SolidFixedCondition.html

BibTeX

@misc{reference.wolfram_2026_solidfixedcondition, author="Wolfram Research", title="{SolidFixedCondition}", year="2021", howpublished="\url{https://reference.wolfram.com/language/ref/SolidFixedCondition.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_solidfixedcondition, organization={Wolfram Research}, title={SolidFixedCondition}, year={2021}, url={https://reference.wolfram.com/language/ref/SolidFixedCondition.html}, note=[Accessed: 12-June-2026]}