# Altair Multi Body Solutions 2022.2 Release Notes

## Highlights

The Altair Multi Body Solutions 2022.2 release includes the following enhancements and bug fixes to MotionView and MotionSolve:
• Support for automatic simulation saves at specified intervals
• New Transfer Case with differential model added for 4WD vehicles in the Assembly Wizard
• IC engine powertrain model added for 4WD vehicles in the Assembly Wizard
• Locking differential system available for vehicles in the Assembly Wizard
• Entity Editors
• Vector entity workflow

## New Features

Automatic Incremental Save
You can now instruct MotionSolve to save the model and states during simulation in specified intervals. Invoke this feature using the Param_Simulation model statement by adding the attributes save_increment and save_inc_overwrite to the XML input file. Automatically saving models is particularly useful for long simulations of complex models and/or co-simulation with other solvers. If, for some reason, the simulation or co-simulation gets interrupted, then MotionSolve can restart a simulation from the last successful saved state, instead of re-starting the simulation from the beginning. Furthermore, you can branch off from a saved model/states and perform model modifications and/or alternative analyses. Currently, save_increment is only available for MotionSolve. UI support in MotionView is planned for a future release.
New Transfer Case with Differential Model Added for 4WD Vehicles in the Assembly Wizard
The Car/Small truck vehicle library in MotionView contains a new Transfer case with a center diff model. This is located in Select driveline systems > Transfer case option.
This option includes a center differential in the driveline system of All Wheel Drive vehicles that splits the engine torque to the rear and front drive shaft using a coupler system with the required ratio.

In the existing Transfer case option, the engine torque is split between the front and rear drive shaft using a force entity representing a viscous coupling.

IC Engine Powertrain Model Added for 4WD Vehicles in the Assembly Wizard
The Car/Small truck vehicle library in MotionView contains a new option for the IC Engine Friction Clutch (Manual) powertrain model for Four Wheel Drive vehicles.
This option represents an automobile powertrain system with an internal combustion engine (IC Engine) and manual clutch. It enables you to create a 3D engine torque map to determine the torque output of an engine based on vehicle states and throttle input. You can also model a gearbox clutch that can be engaged and disengaged by an input signal.
Locking Differential System Available for Vehicles in the Assembly Wizard
A new differential locking system was added to the MotionView Assembly Wizard for Car/Small Trucks and Heavy Trucks.
Beside the existing open differential, you can now define a locking, limited slip, torque-vectoring, or active differential. The new differential lock system consists of a force entity with a torque value as a function of the relative velocity between the wheels.

## Enhancements

The new Run workflow in HyperWorks supports co-simulation with EDEM. In addition, several issues related to solving models containing 2D contacts, deformable curves, and so on have been resolved.
Entity Editor
More entities have an Entity Editor in HyperWorks. Editors are now available for the SolverVariable, SolverString, SolverDiff, Outputs, Polybeam, and Vector entities.
Vector Entity Workflow
The Vector entity has also been enhanced to provide an origin for the vector and graphic visibility. The vector can be oriented along an existing point entity. In the HyperWorks interface, the vector entity can also be oriented graphically.
Linear Sparse Solver
At each Newton iteration, MotionSolve solves the linear systems of equations $\mathbit{J}∆q=-F\left(q,\stackrel{˙}{q},\stackrel{¨}{q},t\right)$ for $∆q$ , where $\mathbit{J}$ is a sparse, unsymmetric Jacobian matrix, $∆q$ includes the unknown differences in states, and $-F\left(q,\stackrel{˙}{q},\stackrel{¨}{q},t\right)$ represents the right hand side. You can now choose between HARWELL, PARDISO, or user-defined sparse solver using SPARSESUB. The default solver is HARWELL; that works best in most applications. The type of linear sparse solver can be selected via the Param_Simulation command in the XML input file and is intended for advanced users only. There is no user interface support for this feature in MotionView.
New Model Function - Distance
MotionView has a new model function to calculate distance between entities. Syntax: distance(entity1, entity2).
Any entity which has a location (Point, Marker, Joint, Bushing) can be used as input. For example, distance(p_point, j_joint) // calculates the distance between point p_point and origin of joint j_joint.
The road files generated using the Road Tools are now saved as *.h3d files instead of *.obj files. This modification brings significant performance improvement related to road generation time, loading time, and output file size.

## Minor Enhancements

• The default maximum iteration for the static solver has been increased to 750.
• In previous releases, the co-simulation was not able to take full advantage of EDEM running on GPUs. In this release, the coupling with EDEM has been enhanced such that EDEM can now better utilize the advantages of GPUs while co-simulating with MotionSolve.
• Flexprep: Craig-Chan-Contact is now supported on Linux
• The modeling statement Post: Graphic has been extended with a new clearance attribute for Triamesh graphics that allows you to superimpose clearance to the existing mesh. The clearance helps meshed graphics in contact with a tight fit to avoid friction and penetration due to the mesh discretization.
• MotionSolve includes the Conditional Numerical Reproducibility (CNR) from Intel® MKL on Windows and Linux. This feature allows MotionSolve to obtain reproducible floating-point results from run-to-run, even if the number of computational threads varies. This feature also improves the reproducibility from PC-to-PC, as long as they have the same architecture and operating system.
• Flexprep is enhanced to use a file for the interface nodes. A keyword argument, -INODESPATH, can be provided followed by a text file containing the node numbers as interface nodes.
• Batch co-simulation with EDEM provides a message if the EDEM installation cannot be found

## Known Issues

• Live animation for flexbodies in the HyperWorks interface shows only the rigid movement of the flexbody. No deformation is shown. This issue will be addressed in a future release.
• Auto assignment of nodes for a flexbody during solver export may assign a coincident node at the interface node location and not the interface node itself. The workaround is to assign the nodes from the Nodes dialog in the flexbody entity.

## Resolved Issues

• Properties in the compliant joint are not shown in the Entity Editor with multiple selection.
• Picked entity is not highlighted for Curve Graphic references when invoked from the Entity Editor.
• File graphic with locator data has incorrect settings for Auto Position and Orient option.
• Incorrect truncation of X data value more than 100 leads to curve visualization error.
• Reference collector in the guidebar for picking single entity allows picking paired entities.
• Application error when using the space bar on Derive from Graphics in the Body Entity Editor.
• A crash is observed when editing Notes for many entities together with the Entity Editor.
• Gravity dialog does not appear on Linux.
• MotionView does not report an error when a motion is applied on a compliant joint.
• Curve interpolation fails in some instances due to precision issue.
• Application error encountered when changing solvermode after adding an NLFE body.
• Application crashes while accessing the Materials dialog after clearing the model.
• Application error encountered in certain cases during co-simulation with FMU generated from MotionView.
• Cannot isolate graphics belonging to Ground Body.
• CM-Labs Vortex translator: Several translation issues are addressed.
• Flexbody with a different body coordinate system is not properly positioned when solved through msolve Py.
• Strain and Stress distribution in ANCF beams was not visualized correctly in HyperView.
• ARYVAL was not working after resizing a smaller Y Array used in GSE.
• FIM_S used to return mode 5 (static) even if a quasi-static simulation was running.
• There were some wrong and misleading component names in the *.abf file when the attribute ypr = True was used in the output requests of the MSolve-API.