Altair MotionSolve 2019 Release Notes
Highlights
Optimization and design capabilities that allow you to synthesize and optimize mechanisms, and conduct design studies. The core solver in MotionSolve now supports the calculation of design sensitivities that can be used to run optimization studies directly, without invoking other software.
New Features
- Optimization
- MotionView, the pre-processor for MotionSolve, fully supports this capability and can be used to setup, run and analyze the results from the analysis.
- MotionSolve Python API
- The optimization problem is expressed in the Python language.
- Optimization Wizard
- Guides you through the entire optimization process in MotionView.
The optimization capability typically involves several solver simulations - one to determine sensitivities for the “initial” design and several consequent “design” simulations to determine and adjust design variables based on responses to satisfy the overall optimization criteria.
The number of “design” iterations depends on the model being optimized and how
stringent the optimization criteria is. To reduce computation time for the overall
optimization process, the “design” iterations do not check out any solver licenses.
The license for an optimization simulation is checked out only once, at the very
beginning of the optimization.
- HWUs per Optimization Job
- The solver will check out 50 HWUs per optimization job, regardless of the number of design iterations being simulated as part of the optimization job.
- Verification Manual
- A set of 12 models spanning kinematics, dynamics, static and linear analyses that serve as verification problems.
Enhancements
Such that the eigen solution obtained when linearizing a model about a non-steady
state operating point are more robust.
- Improved threshold for matrix balancing.
- Improved calculation of the B matrix.
- Updated algorithm for choosing independent coordinates.
- Addition of extra rotational coordinates to all bodies in the mode.
Retrieving gyroscopic effects when performing a linear analysis becomes important
when analyzing rotating systems. MotionSolve can
calculate eigen-solutions that consider gyroscopic effects for rotating systems and
compute “partial” or “full” gyroscopic effects when linearizing a rotating system.
- Partial
- Implies that the angular momentum term is held constant when computing the solution. Here, is the 3x3 inertia matrix of the body in a body-fixed frame and is the angular velocity of the body in that frame. The results from using this approach will typically match reference results from OptiStruct for the same system. This is the default used by the solver.
- Full
- Implies that the angular momentum term described above is not treated as constant when computing the solution.
You can switch between these two options (or disregard the gyroscopic effects
entirely) within the <Param_Linear> model/command
attribute.
| <Param_Linear gyroscopic = | Description |
|---|---|
| NONE | No gyroscopic effects are included in the linear solution. |
| PARTIAL (default) | Angular momentum term is held constant (see Partial description under Enhancements). |
| FULL | Angular momentum term is considered variable (see Full description under Enhancements). |
MotionSolve now supports a newer version of Parasolid, v. 30.0.185. This version is consistent with what is used in MotionView to enable seamless simulations.
Resolved Issues
- In some cases, simulations involving modeling elements attached to the ground body would give incorrect results or even fail. These sets of issues have been fixed by modifying the way the grounded body is treated in MotionSolve.
- Applying rotation on a joint that is connected to a flexible body.
- Saving and loading models containing CDTire, such that there are no failures or discontinuities at the point of save/load.
- For noise in tire forces dependent on an axis of rotation, the solver now switches the Euler angles based on which axes of wheel body aligns with the axis of rotation. This change eliminates the numerical transience, so that choice of axes for the wheel body no longer affects the quality of the results.
- Nosie reduction in inputs when fed to Control_SISO modeling element.
- The seventh parameter in the SWEEP function, the interval over which the function becomes fully active, is now consistent with the definition of the function.