Thermal Desktop®
allows a thermal engineer and structural engineer to
work side by side sharing the same CAD information or
design drawings, while both engineers build distinct
models that are each honed for their individual needs
… even when detailed thermoelastic deformation analysis
is needed. In other words, Thermal Desktop’s unique
model mapping methods means that the thermal model need
not be the same as nor even derived from the
structural model.
While Thermal Desktop can directly import all or part
of structural FEM models, that step is not necessary
to accomplish the accurate export of temperatures and
other thermal data back to a structural code for thermal/structural
analysis. Pitfalls of competing approaches are avoided,
including requirements for "one-to-one" thermal-structural
model correspondence and the errors associated with
using the structural model to do the mapping.
Thermal Desktop allows an appropriate thermal model
to be built using geometric surfaces and solids that
are not faceted, and hence do not lose surface area
needed for accurate radiation, convection, and contact
conductance calculations. It also allows a thermally
appropriate mesh that avoids unnecessary details. Thermal
Desktop users can create their thermal/fluid models
using whatever combinations of finite elements, finite
differences, and lumped parameters suit their needs.
When the time comes to produce temperatures for structural
analyzers such as MSC/NASTRAN, IDEAS/FEA, ANSYS, or
FEMAP, those temperatures are produced at the desired
structural element points using the most accurate representation
possible: the shape functions and interpolation methods
used to produce the temperatures in the first place.
Thermal
Model
Structural
Model
Telescope
Shell
Figure
1
Figure
2
Mirror
Support
Figure
3
Figure
4
For example, the thermal models at the left (Figures
1 and 3) were built independently from the corresponding
structural models at the right (Figures 2 and 4). All
models were generated from the same CAD information.
The thermal model in Figure 1 uses mostly finite differences,
while the one in Figure 3 uses mostly finite elements.
In both cases, temperatures can be mapped to the independent
structural model with a single command.
In fact, using the Dynamic Mode in Thermal Desktop,
such mappings can be made "on the fly" as
part of the analysis procedure during a transient analysis
(e.g., "estimate deflections or thermal stresses
every time slice") or as part a parametric sweep
("estimate thermoelastic responses of each design").
This is possible even if the structural model itself
changes between each mapping. This "hands off"
automated thermal/structural analysis enables design
optimization, statistical design, worst case seeking,
etc.
