Stress Linearization
Use the Stress Linearization node to define a line (stress classification line; SCL) along which a linearization of the stress state will be made. A number of result variables are created for each SCL. Add one Stress Linearization node for each SCL along which you want to compute linearized stresses.
When a Stress Linearization node has been added or modified, you do not need to compute a new solution. It is sufficient to perform an Update Solution () to make the variables for the new SCL available.
The Stress Linearization node is only available with some COMSOL products (see https://www.comsol.com/products/specifications/).
Linearization
Select what Type of linearization to use — Line or Distributed. For Line, the stress is linearized along a single predefined SCL, whereas for Distributed, the stress is linearized in a domain. The direction of the SCL is in the distributed case given by the normal of the selected boundaries from which it originates. In principle, an infinite number of SCLs are created in the domain.
When Line is selected, the SCL can either be defined by a set of edges or by two points. Control this by setting Defined by to either Edge or Two points.
If the SCL is defined by Edge, the Linearization Line, Edge selection can consist of several edges, but they are assumed to form a straight line from one free boundary to another.
If the SCL is defined by Two points, you can either choose to use geometrical points or arbitrary coordinates within the solid to define the endpoints of the SCL. An SCL is created by connecting the two points with a straight line. To control how to specify the endpoints, select either Point or Coordinates in the Starting point defined by and Endpoint defined by lists.
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For Points, select a point in Linearization Line, Starting Point or Linearization Line, Endpoint.
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For Coordinates, enter the coordinate vector of the point.
When Distributed is chosen, select entities in Boundary Selection from which the distributed SCLs start. The SCLs are then created along the normal to the selected boundaries, and extends through the entities selected in Domain Selection.
For 2D and 2D Axisymmetric geometries, no more inputs are need to define the SCL. For 3D, you also need to specify the orientation of the local coordinate system in which the linearized stresses are represented.
Second Axis Orientation
This section is present only in 3D. Here you specify the orientation of the local coordinate system in which the components of the linearized stress tensor are represented. The first direction is always along the SCL, and you indicate the second direction. The third direction is automatically formed by being orthogonal to the SCL and the second direction.
For the Line linearization type, select Reference point or Orientation vector. When a reference point is used, the second local direction will be in the plane formed by the SCL and the selected point. When an orientation vector is used, the second local direction will be directed in the plane formed by the SCL and the selected orientation. The orientation is always adjusted so that it is orthogonal to the SCL.
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For Reference point, select Defined by — Point or Coordinates. When Point is used, select the reference point in the Second Axis Orientation Reference Point section. When Coordinates is used, enter the coordinates for the reference point in the Reference point defining local 2 direction table.
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For Orientation vector select Defined by — Edge or Coordinates. When Edge is used, select an edge in the geometry as orientation vector in the Second Axis Orientation Reference Vector section. When Coordinates is used, enter the orientation vector manually in the Orientation vector defining local 2 direction table.
For the Distributed linearization type, select a boundary system from the Defined by list. The second direction of the SCL is always taken as the first tangent vector of the selected boundary system.
Postprocessing
This section is only present for the Distributed linearization type. Enter the coordinates for the starting point of a SCL; it must be part of the selected boundaries. The specified point is used to create a Linearization Line dataset to postprocess a single SCL that extends from the point through the selected domains.
See also
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Stress Linearization in the Structural Mechanics Modeling Chapter.
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Stress Linearization in the Structural Mechanics Theory Chapter.
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Updating a Solution in the COMSOL Multiphysics Reference Manual
Location in User Interface
Context Menus
Solid Mechanics>Variables>Stress Linearization
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Physics tab with Solid Mechanics selected in the Model Builder tree:
Global>Variables>Stress Linearization