Initial Stress and Strain
You can add the Initial Stress and Strain subnode to the Linear Elastic Material, in order to specify the stress or strain state in the structure before applying any constraint or load. The values given are not initial values in the mathematical sense, but rather a contribution to the constitutive relation..
In many cases Initial Stress and Strain and External Stress are interchangeable when prescribing stresses, but you can find some more options in the latter.
For details about initial stresses and strains, see Initial Stresses and Strains.
Coordinate System Selection
The given initial stresses and strains are interpreted in this system.
For details about how local coordinate systems are used in the Membrane interface, see Local Coordinate Systems.
Initial Stress and Strain
Specify the initial stress as the Initial local in-plane force N0 and the initial strain as the Initial local in-plane strain ε0 (dimensionless). If you know the stress, rather than the force per unit length, type in the stress multiplied by the membrane thickness mbrn.d.In a geometrically nonlinear analysis, the stresses should be interpreted as Second Piola-Kirchhoff stresses, and the strains should be interpreted as Green-Lagrange strains.
•
For details about initial stresses and strains, see Inelastic Strain Contributions and Initial Stresses and Strains.
•
For details about the different strain measures, see Deformation Measures.
•
For details about the different stress measures, see Defining Stress.
Prestressed Micromirror: Application Library path MEMS_Module/Actuators/micromirror
Location in User Interface
Context Menus
 Membrane>Linear Elastic Material>Initial Stress and Strain
 Membrane>Nonlinear Elastic Material>Initial Stress and Strain
Ribbon
Physics tab with Linear Elastic Material or Nonlinear Elastic Material node selected in the model tree:
Attributes>Initial Stress and Strain