Altair Multibody Solutions 2023.1 Release Notes

Highlights

The Altair Multibody Solutions 2023.1 release includes the following enhancements and bug fixes to MotionView and MotionSolve:
  • Run settings enhancements (MotionView)
  • New FMU export with parameters (MotionView)
  • Deformable Curve, Deformable Surface contact (MotionSolve )
  • Frequency response analysis (MotionSolve)
  • Tire test rig analysis in the Entity Browser (MotionView)
  • Tire code version up (MotionSolve)
  • Removal of Create button to define vehicle events (MotionView)

New Features

Run Settings Enhancements
The following improvements to the Run settings, aimed at optimizing the user experience, are outlined below:
  • The Run Defaults menu, accessible from File > Preferences > MotionView, features the following options:
    • Choose Offline as the default solver mode (classic). This turns off the live animation feature, creates a solver input file instead, and calls the solver in a command-line interface.
    • Instruct MotionView to create a folder with the Run name in the working directory. The solver input, log, and output files are stored in this folder instead.
    • Instruct MotionView to print the Python-based API commands for MotionSolve in a file during a live run execution.
    • Select the preferred MotionSolve input file format for offline runs. You can choose between XML (classic) or Python (new python-based API).


      Figure 1.
  • Enhancing the Run settings with options to either run a current active analysis or select an analysis from a list of available analyses.


    Figure 2.
FMU Export with Parameters
The MotionSolve FMU (Functional Mock-up Unit) export from MotionView has been revamped. The updated process provides the option to select modeling attributes as parameters for the FMU. With this feature, the FMU can be made designable aiding the inclusion of the FMU in design variation studies. The FMU can be exported using FMU Editor, accessible from File > Export > Functional Mock-up Unit.


Figure 3.
You can select MotionView entity attributes of types Real, Integer, Boolean, Option, and Filename as a Parameter.


Figure 4.
The editor also displays the Input and Output channels (Solver Array of type Plant Input and Plant Output) for the FMU.
Deformable Curve, Deformable Surface Contact
MotionSolve supports new contact between Deformable Curve and Deformable Surface to other geometries. The supported combinations for contacts are described below:


Figure 5.
Introducing contact for Deformable Curve allows you to model elongated elastic structures, such as cables, pipes, and beams, to be in contact with their surroundings. As an example, you can use this feature to investigate if electrical cables in a robotic arm could get twisted and pinched in the mechanical apparatus. Similar examples exist for contact for Deformable Surface.
The Deformable Curve and Deformable Surface contacts are not yet supported in MotionView.
Frequency Response Analysis
MotionSolve introduces FrequencyResponse as a new analysis capability, designed specifically for conducting frequency response analysis. This analysis is defined by Reference_FrequencyInput, which includes both magnitude and phase angle. You can specify the system excitation on any marker, utilizing forces, displacements, velocity, and acceleration as the basis. The frequency response analysis yields comprehensive results, encompassing output requests of various types such as Marker_Displacement, Marker_Velocity, Marker_Acceleration, and Marker_Force. This ensures a thorough exploration of the system's behavior under different frequencies of excitation, providing valuable insight into its vibration characteristics and dynamic response. This analysis helps identify critical frequencies that may lead to resonance or other undesirable effects.


Figure 6.
This analysis type is not yet supported in MotionView.
Design of Experiments Using msolve API
MotionSolve's Python-based API has been extended with a DOE package for design space exploration. Multiple experiment design types are supported, ranging from factorial to randomized and user-defined designs. You can specify design parameters and response variables for your model. On run, various simulation cases are created and scattered throughout the design space, and then executed either sequentially or in parallel. The output of the DOE can be post-processed either directly in Python, or imported into Altair HyperStudy. The DOE package allows you to navigate the complex landscape of design choices, enabling you to make informed decisions and create optimized and innovative solutions.
Tire Test Rig Analysis in the Entity Browser
The list of analyses available for the tire test rig is now included in the Entity Browser under Vehicle Tools > Events. Use the Entity Editor to modify the analysis parameters.


Figure 7.
This implementation converges the workflow with other models and event selection for a better user experience. To add a tire test rig, select Library ribbon > car and small truck library > Assembly tool > Test rig. Lastly, double-click the test rig events from the Entity Browser to add it in the model and perform the simulation.
Siemens MF-Tyre/MF-Swift Version up to 2306
MF-Tyre/MF-Swift from Siemens distributed with Altair HyperWorks is updated to Simcenter Tire version 2306.
Cosin FTire Version up to 2023-2
MotionSolve now supports the updated version of Cosin F-Tire 2023-2 used in vehicle simulations.

Enhancements

Virtual Joints
MotionView supports the MotionSolve feature to virtualize constraints, such as Joints and Motions.
When marked virtual, a constraint is represented as a soft constraint during the solution instead of a rigid constraint and helps avoid redundancy.
Flexbody Mode Selections
The Set statement for flexbody mode selection, *SetFlexbodyModes(), has been enhanced with the keyword ALL to indicate the selection of all modes.
*SetFlexbodyModes(b_flex, ALL )
New flexible bodies added are saved using this statement going forward. Prior, the mode selection was indicated by the list of mode numbers. This enhancement aids optimization models that use flex bodies as a variable with varying number of modes. It also resolves the problem of mode selections when the flex body is changed to one having additional modes compared to the previous one.
New Units Support
MotionView now covers all units currently supported by MotionSolve. The following units are supported:
FORCE LENGTH MASS TIME
CENTINEWTON NANOMETER TONNE MICROSECOND
MILLINEWTON ANGSTROM MICROGRAM NANOSECOND
MICRONEWTON YARD NANOGRAM DAY
MEGANEWTON MILLIINCH MEGATONNE  
POUNDAL MICROINCH KILOTONNE  
NANONEWTON MILS    
  MICROMETER    
Python Console
Access to the Python Script and Python Window is no longer available through the Model Browser context menu. To access Python Window, use the View menu. Access Python Script with File > Load > Python Scripts.


Figure 8.
Additional Attributes in H3DOutput
MotionSolve supports two additional attributes, linz_animation and frf_animation, to turn on/off the new linear animation results _linz.h3d and frequency response results _frf.h3d.
Removed Create Option to Define Vehicle Events
In the previous release, when adding a vehicle event from the Entity Browser, it was required to confirm the selection and click Create to add the event. Now, double-click the event icon in the Entity Browser to add the event to the model automatically.


Figure 9.
CDTire File Extension
The CDTire file extension contains information used in the simulation, such as tire type and tire pressure (tire_50.21 means type 50 and pressure 0.21Mpa). You can obtain this information from the tire property file, however, the Tire entity in MotionView only accepted the CDTire property file containing type and pressure in the file extension.


Figure 10.
In this release, the CDTire file extension requirement was removed. When loading a CDTire file without the type and pressure extension, in the Tire Entity Editor > CD Tire Options, it is possible to enter the pressure mode required (PIN Mode) and select the tire type.
Enhanced MotionSolve Log Message for MF-Tire/MF-swift ROAD_SOURCE Removal
When updating MF-Tyre/MF-Swift version from 2020.2 to 2212, Siemens deprecated the ROAD_SOURCE attribute in the tire property file. Simulation models with old tire property files, when solved with the newer distribution, failed with an error; making it necessary to remove the line from the tire file to perform the simulation.
The MotionSolve log message flagged the error without providing further guidance. In this release, the log message was enhanced to indicate the error and the actions to take. 
USRMES:USER [1]
INFO: msautoTire_TNO: Please remove the property ROAD_SOURCE from tire property file
ERRMES:USER [1]
ERROR - Conversion failed for property 'ROAD_SOURCE' with value ' 'TNO''

Resolved Issues

  • ID is not displayed for rigid groups in the browser.
  • Python subroutine with relative a path fails in run offline.
  • Unable to export archive of iterations from Review section of the Optimization Wizard.
  • Workflow help for Outputs of type Expression or User-Defined is not correct.
  • Model with kinematic outputs on bodies does not solve with live run.
  • Erroneous move of flexbodies, which has a body coordinate system defined using Euler angles.
  • Entity Browser returns to the root folder when switching views.
  • Live run generates application error for stability event with the option Use vehicle states in linear.
  • DxDyDz field in the Entity Editor goes missing for Marker/Bushing after using options on the screen in Orientation context.
  • Live run does not apply initial conditions on joints.
  • Unresolved attachment causes partial listing of Attachments in the Entity Editor.
  • Valid Scope option in Advanced selection dialog invoked from the Entity Editor does not work.
  • Data set members with NO_EDIT set appear editable in Data Summary.
  • Default run directory under Global Simulation Settings cannot be changed.
  • Application error encountered when closing a Table Form dialog.
  • The Kinetic energy distribution for bodies having inertia across products now shows negative values in distribution.
  • MotionSolve can now support an OptiStruct connection directly with a flexible body without the need for a dummy body.
  • Plane graphics with offset was not displayed in the right position in post-processing.
  • Assembly analysis is not forced in some sequential simulations, which was causing linear analysis to fail.
  • MotionSolve application error when wrong units are specified in Param_Unit.
  • Obstacles with materials defined differently from the road surface or as a rigid are now supported for tracked vehicles on soft soil.
  • A wrong unit input in a control block in the ESP FMU was interfering with the ABS signal for some specific vehicle maneuvers.
  • Distance versus Velocity curve input included in the Altair Drive File (.adf), using non-SI units, was not converted properly in the MotionSolve simulation.
  • MotionView models containing the Aerodynamics file (.aae) was not exporting the file to the solver when using a relative file path.
  • Vehicle models using the Altair Fiala tire with cam contact consumed a large amount of RAM memory based on the number of cams. The issue was causing a long initialization time and a slow simulation.
  • Brake in turn events for a car model failed with a final velocity below 2km/h.
  • Using signal inputs without a file header in the nPost event was causing a solver crash.
  • A unit conversion issue in the engine inertia of the vehicle library models with “IC Engine Friction Clutch (Manual)” was fixed. Consequently, the Engine Inertia value in the Engine and Clutch system > Powertrain Dataset must now be added in the model units (default kgmm2) instead of kgm2.

Known Issues

  • The live animation run option in MotionView currently does not support vehicle models with CDTire.
  • Graphics displayed in AirSpring and F-Tire (Cosin Tire Graphics option selected) remain static during the live animation run option in MotionView. For models containing these graphics, it is recommended to visualize the animation using HyperView.