STRESS/ST and STRESS/EV can be used for stress
analysis. STRESS/ST calculates the deformation, stresses and
strains of a body subject to external and internal forces. The
forces calculated from electromagnetic fields can be used as inpu
to the stress analysis. STRESS/EV calculates the modes, i.e. the
eigenvalues and eigenvectors, of a body that is not subject any
internal or external forces.
Data for STRESS/ST and STRESS/EV can only be created
using the Modeller.
Stress analysis can analyse isotropic, orthotropic
and fully anisotropic materials. It uses the following material
- Young's modulus
- Poisson's ratio
- Shear modulus
- Elasticity matrix (fully anisotropic materials)
- Thermal expansion coefficients (STRESS/ST only)
- General expansion integrals (STRESS/ST only)
- Density (STRESS/ST only)
The material properties can be specified as numeric values or as
expressions. For example, the thermal expansion coefficients could
be functions of temperature or position.
The model can be deformed by internal forces from 3 sources:
- a functional force density, which can use values calculated by
the Post-Processor from an electromagnetic analysis, e.g. EFD, the
element force density;
- rotational forces calculated from a constant rotational
velocity about the global Z axis;
- gravity (any of the 6 major coordinate directions can be
defined as 'down').
External Forces and Constraints
External forces and constraints can be applied globally or as
boundary conditions on the surfaces of the model. The available
forces are (only STRESS/ST):
- pressure, a force density normal to the surface, and
- traction, a force in any direction.
The available constraints that are available for both STRESS/ST
- fixed in all 3 directions;
- fixed in tangential directions;
- fixed in the direction normal to the surface;
The available constraints that are only available for both
- defined normal displacement;
- defined displacement in all 3 directions, and
- thermal expansion, with values for the reference and operating
temperatures, which can be imported from thermal analysis.
- general expansion, which can be used to model magnetostriction,
electrostriction and piezo effects, with the expansion integrals
expressed as functions of magnetic or electric field vectors
imported from electromagnetic analysis.
Eigenvalue Frequency Range
STRESS/EV finds a specified number of eigenvalues above a given
frequency, or within a specified range. Multiple simulations are
created in the analysis database allowing post-processing of each
STRESS/ST and STRESS/EV calculate displacement vectors and
stress (σ) and strain (ε) tensors for display by the
Post-Processor. In addition, the Post-Processor calculates the
invariants and principals of the stress and strain tensors and the
Von Mises stress.