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Since pressure/shear interactions are boundary conditions interactions (LoadingInteraction
), no materials must be associated to the element.
Therefore, the first step consist in defining an ElementProperties
, as
prp = ElementProperties(typeEl) prp.put(param1, value1) prp.depend(param1, fct1, Lock1)) #optional ...
where
typeEl | desired element (for example Traction[2|3]DElement ) |
param1 | name of the property associated to the element (for example PRESSURE ) |
value1 | value of the corresponding property |
fct1 | function which characterizes the dependency of the property (optional: no fct if no dependency) |
Lock1 | Lock which defines the dependency variable of the property (compulsory if there is a dependency) |
Traction/shear element for a mesh made of quadrangles in 2D or hexaedra in 3D.
Name | Description | Dependency |
---|---|---|
STIFFMETHOD | Method used to compute the stiffness matrix = STIFF_ANALYTIC : analytic matrix (default)= STIFF_NUMERIC : numerical matrix | - |
PRESSURE | Pressure on the entity on which the propriety is applied | time |
SHEAR_KSI / SHEAR_ETA | Shear along $\xi$ or $\eta$ on the entity on which the propriety is applied | time |
NPG | Number of integration points (default : 2) | - |
Traction/shear element for a mesh made of tetrahedra
Name | Description | Dependency |
---|---|---|
STIFFMETHOD | Method used to compute the stiffness matrix\\= STIFF_ANALYTIC : analytic matrix (default)= STIFF_NUMERIC : numerical matrix Not applicable, only the numerical one exists ! | - |
PRESSURE | Pressure on the entity on which the propriety is applied | time |
SHEAR_KSI / SHEAR_ETA | Shear along $\xi$ or $\eta$ on the entity on which the propriety is applied | time |
NPG | Number of integration points (default : 1) | - |
Derivations of Traction2DElement and Traction3DElement with the possibility to set the traction/shear force of a node to zero, when this node is in contact within a specified contact interaction. To determine the contact status, the contact flag of the previous time step is used.
The same than in Traction2DElement and Traction3DElement, with the following additional parameter:
Name | Description | Dependency |
---|---|---|
NUM_CONTACT_INTERACTION | Number of the contact interaction, which is tested for the contact status | - |
The interaction is defined as:
load = LoadingInteraction(no) load.push(gObject1) load.push(gObject2) ... load.addProperty(prp) interactionset.add(load)
where
no | number of the Interaction |
gObject1 , gObject2 | meshed geometric entity where the boundary conditions are applied |
prp | Properties of boundary condition elements to generate |
Traction, pressure and shear is generated by “traction elements”. Their definition requires a specific Interaction
called LoadingInteraction
, to which is associated an ElementProperties. These should not be mixed with dead loads. In most cases, traction elements should be chosen over dead loads:
Interaction
is applied. Consequently, the resultant force does not depend on the mesh.
Traction element is used backwards in 3D, so a positive value must be applied to generate a pressure. !!