The Altair GUI Toolkit is a resource tool for coding Tcl/Tk dialogs. It contains documentation of the HyperWorks commands, demo pages that illustrate our Altair GUI standards, and sample code for creating those examples.
The Model Identification Tool, known as HyperWorks, is a profile in HyperGraph for fitting test data from frequency- and amplitude-dependent bushings to analytical models. The HyperWorks operates in conjunction with HyperGraph, MotionView and MotionSolve to provide you with a comprehensive solution for modeling and analysis.
The Altair Bushing Model is a library of sophisticated, frequency- and amplitude-dependent bushing models that you can use for
accurate vehicle dynamics, durability and NVH simulations. The Altair Bushing Model supports both rubber bushings and hydromounts.
This section provides information about using the Altair Bushing Model, also known as AutoBushFD, with MotionView. The Altair Bushing Model is a sophisticated model that you can use to simulate the behavior of bushings in vehicle
dynamics, durability and NVH simulations.
The bodies connected by the bushing are flexible and may deflect under the load being transmitted. This phenomenon
is modeled with the Mount Stiffness feature. Mount stiffness models the structural stiffness of the bodies, thus mounting
the bushing as a linear spring and damper in series with the bushing in each direction.
The Altair Bushing Model includes a Mount Limits feature, which lets you model the material contact that occurs between
the bodies that a bushing connects. The bodies are flexible and may deflect under the load being transmitted. Given
enough bushing deflection, the bodies may contact one another for negative and positive deflections in each
direction.
This section describes how preloads, offsets and scales enter into bushing force computations. You use Preloads, Offsets
and Scales to alter the operating point of a bushing. You can offset the bushing displacement in any direction, and
scale the input displacement and velocity. You can also offset the bushing force in any direction by adding
a preload or scale-output force or moment in any direction.
Coupling refers to the forces and moments generated in a bushing to oppose the overall deformation of the bushing.
These forces and moments are independent of any coordinate system that might be used to measure the deformation or
deformation velocity. Coupling is an important factor when the bushing characteristics are non-linear.
The System Performance Data file, *.spd, contains the test data used for fitting a bushing. This data should be validated to ensure that it is physically
meaningful. One test for physical consistency is that the dynamic stiffness at any amplitude of vibration must always
be greater than the static stiffness at the same amplitude.
HgTrans translates solver results files from their native file format to Altair Binary Format (ABF). This can be done using
the HgTrans GUI or via the HgTrans batch mode.
The HyperWorks Automation Toolkit (HWAT) is a collection of functions and widgets that allows an application to quickly assemble
HyperWorks automations with minimal effort and maximum portability.
HyperWorks Verification and Validation Harness (HVVH) is a tool that can be used to verify and validate HyperWorks products. End users can use this tool to quickly evaluate the software quality, performance, reliability,
scalability, and robustness, and to gain more confidence in HyperWorks products.
Uninstall HyperWorks is a tool to launch the HyperWorks uninstallation program. This program contains two options that allow you to either remove the originally installed
files, or remove all the files that resides in the installation directory.
The Model Identification Tool, known as HyperWorks, is a profile in HyperGraph for fitting test data from frequency- and amplitude-dependent bushings to analytical models. The HyperWorks operates in conjunction with HyperGraph, MotionView and MotionSolve to provide you with a comprehensive solution for modeling and analysis.
The Altair Bushing Model includes a Mount Limits feature, which lets you model the material contact that occurs between
the bodies that a bushing connects. The bodies are flexible and may deflect under the load being transmitted. Given
enough bushing deflection, the bodies may contact one another for negative and positive deflections in each
direction.
The Altair Bushing Model includes a Mount Limits feature, which lets you model the
material contact that occurs between the bodies that a bushing connects. The bodies are
flexible and may deflect under the load being transmitted. Given enough bushing deflection,
the bodies may contact one another for negative and positive deflections in each
direction.
When bushings deflect, a large amount of contact can occur between the bodies they
connect limiting the deflection. However, these limits are dependent on the geometry
of the bodies and are not an intrinsic bushing property. Therefore mount limits are
specified in a separate Mount Limits Property
File (*.gbi). In this file you can:
Activate mount limits for a bushing.
Define gap, stiffness and damping properties that are appropriate for the bodies
that the bushing connects.
When the bushing deflection closes the gap between the bodies in a specific
direction, the mount limit in the corresponding direction exerts a force or torque
to limit the deflection. The following image shows how such a contact can occur at
the connection between the A-Arm and the Strut in a suspension.
The mount limit force or torque adds to the bushing force or torque and acts to
increase the normal force or torque input to the bushing friction and the local
deflection of the bodies.
Mount Limits depend on the geometry of the bodies that mount the bushing, and not the
bushing itself. Therefore, the displacement and velocity used for computing the
mount limit forces and moments, unlike the bushing, is not scaled, offset or
coupled.
You can define positive and negative mount limits for any set of bushing directions:
{FX, FY, FZ, TX, TY, and TZ}.
A positive mount limit acts to limit positive displacement in a given direction
by producing a negative force or torque.
A negative mount limit acts to limit bushing negative displacement and produces
a positive force or torque.
All the input parameters like stiffness, gap, and exponent for either positive
or negative mount limits are always entered as positive values.
Positive Mount Limits
Let:
be displacement and velocity between the I body and J body less any local
structural deflection as computed by the mount-stiffness
CONTROL_STATEEQN.
be the gap that must be closed for material contact to occur.
be the stiffness of the limit.
be the exponent applied to the deflection. ≥ 1.0 to ensure a constant or rising
stiffness rate with deflection.
be the damping coefficient.
be the deflection at which the damping is fully active. For deflections less
then , the damping force is modified by the step
function to prevent discontinuity of the contact force.
Then the force or torque in the kth direction for a positive mount limit
is defined as:
if (Mount_Limits_Are_Inactive OR )
= 0.0
else
Negative Mount Limits
For a negative mount limit, the limit force is computed in the same manner as a
positive mount limit, however the input displacement and velocity are negated as is
the output force. Again all the input parameters are positive. The force/torque
computation for a negative mount limit is: