The Altair Multi Body Solutions 2020 release comes with new functionalities and
several enhancements. Here is a consolidated list:
New Two-Wheeler and Three-Wheeler Solution
New Vehicle Tools Update Model Utility
New Drum Road for FIALA Tire
Altair Driver Improvements
Enhanced Road File Support
Improved Suspension Design Factors
MDL Vehicle Library Changes
Enhancements to MotionSolve – EDEM Interface
Enhancements to Multi-Disciplinary Tools
Enhancements to Linear Analysis
Enhancements to Rigid Body Contact
Enhancements to Functional Mock-up Unit (FMU)
Other Enhancements
General Known Issues
General Resolved Issues
New Two-Wheeler and Three-Wheeler Solution
The 2020 release of MotionSolve provides a comprehensive solution for two-wheeled
vehicles such as motorcycles, bicycles and scooters. Figure 1.
The key features of the solution are:
Two-Wheeler library of parametric subsystems
Assembly Wizard to quickly assemble vehicles
Two-Wheeler and Leaning-Three-Wheeler Driver
Two-Wheeler Tire
Comprehensive event library
Three-Wheeler Example Models
Two-Wheeler library of parametric subsystems
The 2020 release of MotionSolve contains a new library for modeling
two-wheeled vehicles like motorcycles, bicycles and scooters. The
library includes:
Classic or inverted front fork with rigid or deformable strut
rods
Mono-shock or twin shock rear fork
Rider mass and simple or complex graphics
Chain drive
CAD graphics for good model appearance
Assembly Wizard to quickly assemble vehicles
The Assembly Wizard builds full two-wheeler models containing the
subsystems listed above. Half vehicle (suspension) models are not
supported.
Two-Wheeler and Leaning-Three-Wheeler Driver
Altair Driver supports new steer and lean controllers for two-wheeled
and leaning-three-wheeled vehicles.
For closed loop path following, the steer and lean controllers
act in concert to steer and balance the two-wheeler as needed to
follow the path.
For open loop events with two-wheeler and leaning-three-wheeler
vehicles the lean angle is input as a function of time, the
driver steers the front fork to achieve the lean angle while
maintaining balance and the resulting vehicle path in the event
output.
By default, vehicles with two wheels use the leaning driver
configuration and events. Vehicles with three or more wheels use the
non-leaning driver. If your three-wheeler vehicle is leaning, you can
override the default non-leaning driver configuration from the driver
panel shown below. Figure 2.
Note: The driver does not interact with the vehicle through the
rider, only through the steering.
Two-Wheeler Tire
Altair’s free FIALA Tire model has been extended to include
camber-dependent lateral force and tire-road contact for rounded tire
cross-sections. These changes make the FIALA model suitable for 2- or
3-wheelers. DELFT-TYRE, packaged with MotionSolve, also includes the
MFMC-TYRE model for use with two-wheeler and leaning-three-wheeler
vehicles.
Known Issue
At high camber angles seen in two-wheeler vehicles, the FIALA tire
incorrectly adds energy to the vehicle for unknown reasons.
Comprehensive event library
All existing passenger car full vehicle events are supported for 2- and
3-wheeled vehicles also.
New Three-Wheeler Example Model
An Auto-Rickshaw example model is now available. It is built by
combining a front fork system from the Two-Wheeler library with a
quadra-link rear suspension system from the Car library. This model
illustrates how systems from different libraries can be combined to
create unique vehicles that can use Altair Driver with its set of
events.
Note that Altair Driver is enhanced to:
Generalize and reduce the number of attachments to the vehicle
Detect the vehicle configuration based on the number of wheels and
tires
With these enhancements Altair Driver adapts its feedforward path control to match
the vehicle configuration, be it a two-wheeler, three-wheeler, car or multi-axle
heavy truck.
New Vehicle Tools Update Model Utility
The HyperWorks 2020 release introduces an Update Model utility on the Vehicle Tools
menu you can use update models to use 2020 MotionAuto System Definitions. A
description of the updates is given in the table below. The update only functions
for models created in HyperWorks v2107.3 or later.
When you open full vehicles models using Altair Driver, you will receive an alert
asking you to update your model. For half vehicle models, no alert is given. If you
choose not to update your model, it will work in the HyperWorks v2020 release. If
you save your model to disk from HyperWorks v2020 without executing the Update Model
function, you will not be prompted to update again.
If you do choose to update your model, a back-up of the model is saved to disk with
“_backup” appended to the name, the model is updated (see the table below for the
update actions) and the updated model is save to disk with “_updated" appended to
the name.
Description
Affected Entities
Actions
Legacy tire systems replaced by AutoTire
Any systems using the AutoCDTire, AutoCTITire, or AutoMFTire
system definitions
Single and pair systems using the AutoCDTire, AutoCTITire or
AutoMFTIre system definitions are replaced with a single or pair
system using the AutoTire system definition. Attachments and
parameters like the tire and road property file are
unchanged.
Dummy Steering Bodies removed
Steering systems
Full and Half Vehicle Events
(analyses)
Dummy steering bodies and associated joints are deleted from
steering systems (sys_steering), and from full and half vehicle
events (analyses). Steering system joints are modified so the
rack joins to the rack housing via a translational joint, the
pinion to the rack housing via a revolute joint and the pinion
to rack via a coupler.
Old Altair Driver System replaced by new system
Altair Driver system
The Altair Driver system is replaced with the new 2020 Altair
Driver system. If needed the Altair Driver system definition is
updated to use an *DefinitionInclude()
pointing to the Altair Driver system definition in your
HyperWorks 2020 installation folder.
Signal Generator System moves to Altair Driver
Signal Generator (.sys_signal_generator)
The user signals solver variables move to the Altair Driver
System. You now create expressions for user signals from the
Altair Driver system panel. The signal generator system is
deleted from the model.
Known Issues
For models containing AutoCDTire systems that are updated to
AutoTire, you need to reselect the tire property files before
running a simulation.
For models created in HyperWorks versions older than v2017.3,
update model will leave attachments for instrumentation systems
unresolved.
New Drum Road for FIALA Tire
FIALA tire offers a new drum road where you specify the drum profile as drum height
tabulated against drum circumference. You can enter the drum profile in the road
property file directly or reference a .csv file to define the
drum profile. Similarly, you can enter the drum surface velocity tabulated against
time in the road property file or reference a .csv file to
define the velocity verses time.
The center of the drum is automatically positioned under the wheel center, but you
can also set the position of the drum relative to the road reference marker from the
road property file. In addition, drum graphics are created for post processing. You
set the width (length) of the drum cylinder and the number lines to draw on the
cylinder surface in the road property file.
Altair Driver Improvements
Altair Driver is improved to make it easier to add the driver to vehicle models not
built using the Assembly Wizard and MDL library systems. Specifically, Altair
Driver:
May be added to your vehicle model from the browser context menu Add Auto
Entity.
Needs 13 fewer attachments compared to the previous version.
Does not require a separate signal generator system. The signal generator
system is now part of the Altair Driver system.
Identifies the direction the steering wheel or rack needs to move to make
the vehicle turn left. This allows Altair Driver to steer the vehicle to
follow a path independent of how the steering wheel or rack joint are
constructed providing, of course, that the steering wheel and rack are
connected to the steered wheels.
Identifies the number of wheels and tires in your vehicle to infer the
vehicle type the best feedforward steering controller to use. However, you
can override the vehicle type in the Altair Driver panel.
Includes fields on the Altair Driver panel to identify your vehicle’s
forward and vertical directions in the global coordinate system. This allows
Altair Driver to correctly orient paths relative to the vehicle.
Altair Driver requires that your model use AutoTires for modeling tires in your
vehicle. However, the new update model feature will convert old tire systems to
AutoTires to ease the transition.
Enhanced Road Support
The HyperWorks v2020 release extends support for OpenCRG, Point Cloud (3D Shell), and
3D Spline Road property files to all supported tire models (CDTire, DELFT-TYRE,
FIALA, and FTIRE) to eliminate the need to convert road property files from one
format to another based on the tire model used.
Example road property files are provided in the HyperWorks installation at
…\hwdesktop\hw\mdl\autoentities\properties\Altair_Roads.
Improved Suspension Design Factors
Virtual Steer Axis Outputs
The suspension design factors (SDFs) virtual steer axis outputs are
improved to give more accurate results. When calculating the virtual
steer axis and values derived from the steer axis like virtual scrub
radius and virtual caster trail, the suspension spring travel is locked
by numerically manipulating the compliance matrix. Locking the spring
travel eliminates any coupling between the suspension steering and ride
motions yielding better results.
To facilitate the locking, the spring systems in MDLLIB suspensions now
include a travel lock system. The travel lock system identifies the
spring marker on the un-sprung body, the spring type: translational or
rotation (for example, torsion bar) and primary direction of spring
motion for use by the functions computing the virtual steer axis.
Because the locking is done only on the compliance matrix input to the
SDF computations, it has no effect on the suspension behavior or
analysis results.
Roll Center Height
The roll center height calculation is updated to show negative values
(roll center below the road surface). Previously, the absolute value of
the roll center height was output giving incorrect results for some
suspensions.
MDL Vehicle Library Changes
There are several changes to the MDL Vehicle Library in the v2020 release which are
summarized below:
The Assembly Wizard option to build a Full Vehicle without Altair Driver is
removed. But you can add the option by setting the environment variable:
HW_MA_LEGACY_WIZARD=1.
Steering Dummy bodies and their associated joints in steering systems and
analyses are removed.
Spring travel and steering locks are added to suspension systems and
analyses to facilitate calculating suspension design factors like virtual
steer axis.
The signal generator system moves to the Altair Driver system.
The Altair Driver system has fewer attachments to facilitate its use with
two-wheeler and three-wheeler vehicles as well as cars and trucks.
Known Issue
The Wizard library selection (for example Car/Small Truck, Heavy Truck,
Two-wheeler) is not saved to the .mdl file.
Therefore, if you export wizard selections for a car model, select the
Two-wheeler library, and then import car model wizard selections, the
model created is a two-wheeler not a car. Reselecting the Car/Small
Truck library and then importing the car model wizard selections will
re-create the car model.
Enhancements to MotionSolve-EDEM Interface
In the v2019.1 release, MotionSolve added the capability to interface with the bulk
material simulation software EDEM. This release presents further enhancements to
this interface.
Linux Support
The EDEM co-simulation interface is now available on the Linux
platform.
Cross-Platform Support
The interface can be used across heterogenous operating systems.
MotionView/MotionSolve may run on Windows and EDEM on Linux and
vice-versa. Figure 3. (Left) Co-simulation on the same machine. (Right) Simulation
of cross-platform.
The EDEM Subsystem panel is updated to transfer graphics to EDEM and
create an EDEM system across heterogenous platforms. Figure 4.
Improvements in H3D Generation
Generation of the EDEM particle
.h3d file is now optional and occurs at the
end of the simulation greatly reducing memory usage. Note that the
EDEM system needs to be generated afresh to use this option.
Previously, the .h3d file for the EDEM
particles was always generated during simulation. Figure 5.
Coupling Start Time
The co-simulation interface is enhanced to allow the MotionSolve
simulation to run for some time before starting the EDEM simulation. An
additional field “Start EDEM simulation at time” is available in the
EDEM subsystem panel. This feature is particularly useful for EDEM
models whose start time is not 0.0 (for example, a pre-solved EDEM
simulation until time T0). Figure 6.
Batch Simulation
A batch script is now available to run the co-simulation in batch mode.
The scripts msedemcosim.bat for Windows and
msedemcosim.sh for Linux are located at
~install/hwdesktop/utility/mbd/edem.
Syntax to run the batch script:
msedemcosim.bat mvmodel.mdl
edemmodel.dem
Where mvmodel.mdl
and edemmodel.dem are the MotionView and EDEM
models respectively.
Enhancements to Multi-Disciplinary Tools
The Multi-Disciplinary Tools (available through the Preference) offers the following
new features.
Altair/Compose™ functions for use in conjunction with
MotionView/MotionSolve
dsarun (Analysis features) - Submit
multiple MotionSolve simulations with different values of a
single parameter.
ms_dsafftplot / ms_dsafrfplot (Plotting -
Compose) - Comparison plot of MotionView dsarun results in time
and frequency domains, either as FFT of output signal or
estimated FRF between output and input signal.
ms_frfplot (Plotting - Compose) - Compute
and plot FRF between plant outputs / inputs from any MotionSolve
linear analysis job.
A quick road builder tool road4durability (Experimental)
Build complex 3D CRG road profile with three lanes made of a series of
obstacles to enable 2, 3 & 4 wheelers durability analysis. This
feature is experimentation. To use the feature, set the environment
variable HW_MD_EXPERIMENTAL=ALL.
Refer to the
Multi-Disciplinary Tools help for additional details.
Enhancements to Linear Analysis
A, B, C, and D state matrices in OML format
MotionSolve can now create state space matrices in the OpenMatrix
Language (OML) format. These matrices can be directly loaded into
Compose and Activate for further analysis. An option to write
Compose/Activate state-space matrices during a Linear Analysis is now
available under the Run Panel > Simulation Settings > Linear in MotionView.
Kinetic and Strain Energy for Flexible Bodies
MotionSolve can calculate the kinetic/strain energies and dissipative
power for flexible bodies that are defined using Component Mode
Synthesis (CMS).
Modal Energy Distribution
MotionSolve can write an HTML file with the modal energy distributions.
The HTML file aids in understanding how the energies are distributed
across the different mode shapes.
Resolved Issues
Eigenmodes were not displayed correctly in HyperView for some models.
Linear Analysis with tire models sometimes caused a software crash.
The 3D meshed contact algorithm has been enhanced
with an additional optional node-based method for computing the
contact kinematics. This feature calculates the normal forces on the
nodes of the surface mesh, instead of the center of the mesh
triangles. The node-centric contact feature provides improved
accuracy, particularly in situations where large penetration occurs
due to sharp edges in contact. Figure 7. Extreme contact penetration example. (Left) Contact Forces
acting on element center. (Right) New node-based contact feature
with reaction forces acting on nodes. Note that at the edge on
the lower left of the green box, the contact force is inclined
as expected.
This option can be set in MotionView in the Contact panel –
Advanced tab. Figure 8.
Cylinder in Cylinder Contact
The contact model in MotionSolve allows the contact between a cylinder
inside another cylinder to be calculated analytically using the
is_material_inside flag. Also, cylinder inside
cylinder is supported for open and capped cylinders (inside and
outside). The analytical contact formulation has advantages in terms of
speed and accuracy compared to the mesh-based contact calculation. Figure 9. Cylinder in cylinder contact. (Left) Mesh-based contact
calculation. (Right) Analytical-based contact analysis. Note
that the contact force distribution is much smoother for
analytical contact.
Known Issues
The following known issues will be addressed in a future release as we
continuously improve performance of the software:
The node-centric feature of the 3D meshed contact can provide
inaccurate results for complicated-shaped contact patches. In these
situations, you are encouraged to simulate contact with reaction forces
resolved at the element center.
Enhancements to Functional Mock-Up Unit (FMU)
Coupling at T > T0
The co-simulation capabilities of MotionSolve with Functional Mockup
Units (FMU) allows starting a coupled simulation at T > T0, meaning
MotionSolve simulates the system without the FMU from T0 (start time) to
T (coupling time). This allows for computational performance
improvements where the dynamic influence of the FMU is only relevant at
time greater than T0, and where the FMU is computationally expensive
(example: FE based model).
Kinematic Analysis
The co-simulation capabilities of MotionSolve with FMU supports
kinematic analysis.
Compliance Checks
Improved compliance checks make the co-simulation
with FMUs more robust. Here, the validity of the FMU is being
checked against the FMI standard and warnings/errors are being
reported in situations where the FMU does not comply with the
standard. An option to Check
FMU for compliance is available in the MotionView FMU
panel.
Resolved Issues
Some crash issues related to setting input variables and reading
FMU have been fixed.
Incorrect FMU paths written to the solver deck in a different
folder are fixed.
An ID assignment issue for solver variables in a model
containing FMU is also fixed.
Issues that prevented an FMU temp folder from being deleted
after a completed simulation have been addressed.
FMUs exported from MotionView now work on Linux platform.
Other Enhancements
FlexPrep
This utility now supports all unit choices offered by OptiStruct when
generating flexbodies.
Solver Array - IC
The export of solver array of type IC has been updated to write the entries
in integer or real form instead of scientific notation. This makes it easier
when entries in the IC array are IDs of other solver elements.
Outputs
Output
Type
Label as seen in result files
Comments
Displacement
Velocity
Acceleration
Two Points
Body 1 from Body 2 (output_label)
output_label is the label of the Output
entity
connecting_entity
is the force inducing entity that is associated with
the body such as Joint, Bushing, SpringDamper
etc.
Entity/Entity Sets - Bodies
Body (output_label)
Entity/Entity Sets - other entities
Entity on Body (output_label)
Force
Entity/Entity Sets - Bodies
connecting_entity on Body (output_label)
Entity/Entity Sets - other entities
Entity on Body (output_label)
Allow Compliance Option for Joints
This option is turned ON by default when adding joints.
Export MDL Snapshot in the Run Panel
This option is now turned ON by default.
NLFE Belt Pulley System
The limitation of creating an NLFE Belt Pulley system with more than 300
elements is removed. MotionView warns you of potentially large solution
times in this case.
Python Subroutines
PINSUB and POUTSUB for Plant Input
and Plant Output respectively are now available as python
subroutines.
User Subroutines
A new XML configuration file now allows you to customize the
UserSubBuildTool.exe for your
environment.
Also, user subroutines now support Visual Studio 2005
– 2019 and Intel Fortran 10 – 2020. Furthermore, the installation of
a Fortran compiler is not necessary anymore if the subroutine
consists on C/CPP files only. In such cases, you only require Visual
Studio (the Fortran compiler is not needed).
General Known Issues
Road Tools incorrectly positions the shoulder graphics for 3D Spline
Roads.
Road Tools does not create centerline or shoulder graphics for Point Cloud
Roads.
FMU exported from earlier version of MotionView will not readily work with
HyperWorks v2020. A script fmu_patch.bat available at
~install/utility/mbd/fmu should be used to upgrade
it.
There is a change in the folder structure of HyperWorks. Any custom scripts
that uses the environment variable ALTAIR_HOME to locate
the solver needs to be updated.
General Resolved Issues
MotionView
Roll Center Height: The roll center height calculation is updated to show
negative values (roll center below the road surface). Previously, the
absolute value of the roll center height was output giving incorrect results
for some suspensions.
MacPherson Strut Camber Angle: Camber angle for MacPherson strut suspensions
is now output correctly. Previously, a marker was not attached to the
correct body.
Check Model took a long time for models having a large set of outputs.
Importing a MOTION of type ACCELERATION with a function expression from ADM
resulted in an error.
CG Inertia Summary was erroneous in certain cases when Body coordinate
systems were used along with Properties from Associated graphics.
Mass and inertia for Auto-Tires were not being reported in CG Inertia
Summary.
The issue of including solver arrays within deactivated systems while
exporting the model as FMU has been resolved.
Adding certain forms of FMU into the MotionView model resulted in a
crash.
Expressions in the Input tab of the FMU was not possible without invoking
the Expression Builder in certain cases.
FMU paths were not written relative to the exported MotionSolve xml.
Deactivating FMUs resulted in other solver variables losing their assigned
IDs.
Graphics enclosed within another graphic whose display is set to
wireframe/feature lines could not be selected or picked.
Models containing CADGraphics having an ampersand (&) in their name
resulted in solver failure.
The help link to MotionSolve Functions from the Expression Builder was
broken in version 2019.1.
CAD feature recognition is not exited during certain specific mouse
movements away from the screen.
Mouse hover on points with left click press and the Point collector active
in the CAD feature recognition ON results in a crash.
Switching to a HyperGraph window after editing curve values in MotionView
resulted in an application error.
Creating File Graphics successively using FEM files resulted in distortion
in graphic display.
Auto-MFTires referring to bodies that derived properties using associated
graphics resulted in erroneous marker orientations in the solver deck.
Incorrect DOF calculations during Check Model (Tools > Options > Check Model
> Degrees of Freedom) for entities under analysis, polybeams and compliant
joints are fixed.
MotionSolve
After a reload, results of a model with COUXX2 were discontinuous.
The damping ratios generated by MotionView were not scaled properly if
non-default units were used during a CMS run in OptiStruct.
The distributed load on a flexible body has two components: a rigid body
component that has a tendency to accelerate the flexible body that it is
acting on, and, a modal component that has a tendency to deform the flexible
body that it is acting on. The distributed force created by
Force_FlexModal was not scaled correctly on the rigid
body component when non-default units were used.
