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.
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.
A first order filter, with cutoff frequency R, is used to identify
the dynamic component, x , of the input signal,
X. The transfer functions of the signal sent to the dynamic
and the static models, assuming X0=0, are:
The following are Bode plots for these transfer functions:
Figure 1.
The Bode plots show the magnitude and loss angle of the transfer functions over a
range of operating frequencies:
The top figure plots the magnitude of the transfer function against
Log10(ω/R).
The bottom figure plots the loss angle of the transfer function against Log10(ω/R).
Plots of the signal sent to the dynamic model are gray-blue.
Plots of the signal sent to the static model are brick-red.
The log scale used for the x-axis lets you view a wide range of frequencies and
filter behavior as follows:
When (ω/R) ≪ 1, that is at low frequencies, then:
The magnitude of the signal sent to the dynamic model is close to
0.
The loss angle of the signal sent to the dynamic model is close to
90°.
The magnitude of the signal sent to the static model is 1.
The loss angle of the signal sent to the static model is 0°.
The bushing essentially behaves as the static model. The loss angle of
the signal sent to the dynamic model is close to 90°, but this is not
important since the magnitude of the signal is close to zero.
When (ω/R) ≫ 1, that is at high frequencies, then:
The magnitude of the signal sent to the dynamic model is close to
1.
The loss angle of the signal sent to the dynamic model is close to 0°
.
The magnitude of the signal sent to the static model is 1.
The loss angle of the signal sent to the static model is 0°.
The bushing essentially behaves as a dynamic model superimposed on top
of a static model.
When (ω/R) ≫ 1, that is at cut-off frequency, then:
The magnitude of the signal sent to the dynamic model is 1/√2≈0.701.
The loss angle of the signal sent to the dynamic model is 45°.
The magnitude of the signal sent to the static model is 1.
The loss angle of the signal sent to the static model is 0°.
The bushing essentially behaves as a dynamic model superimposed on top
of a static model.