StructuralBC Properties

Boundary condition or boundary load for structural analysis model

A StructuralBC object specifies the type of PDE boundary condition or boundary load on a set of geometry boundaries. A StructuralModel object contains a vector of StructuralBC objects in its BoundaryConditions.StructuralBCAssignments property.

To specify boundary conditions for your model, use the structuralBC function. To specify boundary loads, use structuralBoundaryLoad.

Properties of StructuralBC

RegionType — Geometric region type

'Face' for 3-D geometry | 'Edge' for 2-D geometry

Geometric region type, returned as 'Face' for a 3-D geometry or 'Edge' for a 2-D geometry.

Data Types: char | string

RegionID — Geometric region ID

vector of positive integers

Geometric region ID, returned as a vector of positive integers. Find the region IDs by using pdegplot with 'FaceLabels' (3-D) or 'EdgeLabels' (2-D) set to 'on'.

Data Types: double

Vectorized — Vectorized function evaluation

'off' (default) | 'on'

Vectorized function evaluation, returned as 'off' or 'on'. This evaluation applies when you pass a function handle as an argument. To save time in the function handle evaluation, specify 'on', assuming that your function handle computes in a vectorized fashion. See Vectorization. For details on this evaluation, see Nonconstant Boundary Conditions.

Data Types: char

Boundary Constraints and Enforced Displacements

Displacement — Enforced displacement

numeric vector | function handle

Enforced displacement, returned as a numeric vector or function handle. The numeric vector must contain two elements for a 2-D model and three elements for a 3-D model. The function must return a two-row matrix for a 2-D model and a three-row matrix for a 3-D model. Each column of the matrix must correspond to the enforced displacement vector at the boundary coordinates provided by the solver.

Data Types: double | function_handle

XDisplacement — x-component of enforced displacement

number | function handle

x-component of the enforced displacement, returned as a number or function handle. The function must return a row vector. Each column of the vector must correspond to the value of the x-component of the enforced displacement at the boundary coordinates provided by the solver.

For axisymmetric models, this property contains the radial component (r-component) of the enforced displacement.

Data Types: double | function_handle

YDisplacement — y-component of enforced displacement

number | function handle

y-component of the enforced displacement, returned as a number or function handle. The function must return a row vector. Each column of the vector must correspond to the value of the y-component of the enforced displacement at the boundary coordinates provided by the solver.

For axisymmetric models, this property contains the axial component (z-component) of the enforced displacement.

Data Types: double | function_handle

ZDisplacement — z-component of enforced displacement

number | function handle

z-component of the enforced displacement, returned as a number or function handle. The function must return a row vector. Each column of the vector must correspond to the value of the z-component of the enforced displacement at the boundary coordinates provided by the solver.

Data Types: double | function_handle

Constraint — Standard structural boundary constraints

'free' | 'fixed' | 'roller' | 'symmetric' | 'multipoint'

Standard structural boundary constraints, returned as 'free','fixed','roller', 'symmetric', or 'multipoint'.

Data Types: char

Radius — Radius of circle (for 2-D geometry) or sphere (for 3-D geometry) around reference point location for multipoint constraint

positive number

Radius of a circle (for a 2-D geometry) or a sphere (for a 3-D geometry) around the reference point location for the multipoint constraint, returned as a positive number.

Data Types: double

Reference — Reference point location for multipoint constraint

2-by-1 numeric vector | 3-by-1 numeric vector

Reference point location for the multipoint constraint, returned as a 2-by-1 (for a 2-D geometry) or 3-by-1 (for a 3-D geometry) numeric vector.

Data Types: double

Boundary Loads

Force — Concentrated force

numeric vector | function handle

Concentrated force at a vertex, returned as a numeric vector or function handle.

Data Types: double | function_handle

SurfaceTraction — Normal and tangential distributed forces on boundary

numeric vector | function handle

Normal and tangential distributed forces on the boundary (in the global Cartesian coordinates system), returned as a numeric vector or function handle. The numeric vector must contain two elements for a 2-D model and three elements for a 3-D model. The function must return a two-row matrix for a 2-D model and a three-row matrix for a 3-D model. Each column of the matrix must correspond to the surface traction vector at the boundary coordinates provided by the solver.

Data Types: double | function_handle

Pressure — Pressure normal to boundary

number | function handle

Pressure normal to the boundary, returned as a number or function handle. The function must return a row vector in which each column corresponds to the value of pressure at the boundary coordinates provided by the solver. A positive value of pressure acts in the direction of the outward normal to the boundary.

Data Types: double | function_handle

TranslationalStiffness — Distributed spring stiffness

numeric vector | function handle

Distributed spring stiffness for each translational direction used to model an elastic foundation, returned as a numeric vector or function handle. The numeric vector must contain two elements for a 2-D model and three elements for a 3-D model. The custom function must return a two-row matrix for a 2-D model and a three-row matrix for a 3-D model. Each column of this matrix corresponds to the stiffness vector at the boundary coordinates provided by the solver.

Data Types: double | function_handle

Time Variation of Force, Pressure, or Enforced Displacement

StartTime — Start time for displacement component, pressure, or concentrated force load

nonnegative number

Start time for a displacement component, the pressure, or the concentrated force load, returned as a nonnegative number.

Data Types: double

EndTime — End time for displacement component, pressure, or concentrated force load

nonnegative number

End time for a displacement component, the pressure, or the concentrated force load, returned as a nonnegative number.

Data Types: double

RiseTime — Rise time for displacement component, pressure, or concentrated force load

nonnegative number

Rise time for a displacement component, the pressure, or the concentrated force load, returned as a nonnegative number.

Data Types: double

FallTime — Fall time for displacement component, pressure, or concentrated force load

nonnegative number

Fall time for a displacement component, the pressure, or the concentrated force load, returned as a nonnegative number.

Data Types: double

Sinusoidal Variation of Force, Pressure, or Enforced Displacement

Frequency — Frequency of sinusoidal displacement component, sinusoidal pressure, or concentrated force

positive number

Frequency of a sinusoidal displacement component, the sinusoidal pressure, or the concentrated force, returned as a positive number, in radians per unit of time.

Data Types: double

Phase — Phase of sinusoidal displacement component, sinusoidal pressure, or concentrated force

nonnegative number

Phase of a sinusoidal displacement component, the sinusoidal pressure, or the concentrated force, returned as a nonnegative number, in radians per unit of time.

Data Types: double