View Data

Use the View Data tab to specify, plot and view your data. The tab is divided into three working sections: Dynamic Data, Static Data, and Curve and Plot Properties. A fourth section displays a static image of the Conceptual Cubic.

  1. Use the Dynamic Data area of the tab to define the display layout for dynamic stiffness and loss angle measurements.
    1. Click the For each, Then for each and Show data for each files fields to determine the sorting of your data by direction, amplitude and preload.
      For each direction, data for a specific amplitude is displayed in a plot window. In each plot window several curves are drawn—one for each preload. Each curve is the graphical representation of the dynamic stiffness (loss angle) vs. frequency relationship.
    2. Click the Separate plots for dynamic stiffness & loss angle to specify whether the dynamic stiffness and loss angle are to be plotted in the same window or in separate windows (default).
  2. Use the Static Data area of the tab to determine how to display the static properties derived from the experimental measurements. The tab includes three representation options for the static data.
    • The Spline Data section uses data obtained from the static testing of the physical bushing that is stored in the .spd file.
    • The Constant Stiffness area displays the linear fit to the spline data. The slope at the operating point, OS, is used to represent the bushing stiffness in that direction. Note that constant damping as a default is assumed to be 1% of the constant stiffness.
    • The Conceptual Cubic area defines the cubic polynomial that approximates the spline data. For more information, see Features of the Altair Bushing Model and refer to sections on Stiffness Force Models, Damping Force Models, and the Bushing Property File (.gbs).
  3. Use the Curve and Plot Properties options to define the line-style and line-thickness for dynamic stiffness and loss angle curves. The default option is a line-style and coloring scheme that shows the most contrast between the curves.
    1. Click Common axis range for curve plots to specify that all plots for dynamic stiffness or loss angle use a common range for the x- and y-axes. Using the same axis range is useful for visually examining the curves.
      Note: If the option is not selected, MIT determines the range for each plot, which is useful when you need more detail.  In addition, HyperGraph lets you manually zoom in and out on the curves.
    2. Click Start y-axis at zero to specify that all plots for dynamic stiffness or loss angle start with a y-value of zero. This option is useful when you want to zoom out and visualize experiment and model behavior on an absolute scale.
  4. Use the series of four buttons at the bottom of the View Data tab to do the following:
    1. Click Save Settings to save the dynamic data, curve, and properties preferences for reuse.
    2. Click Load Settings to load previously saved preferences for dynamic data and curve and plot properties.
    3. Click Append Plots to append new curves to an existing HyperGraph session.
    4. Click New Plots to clear the HyperGraph session and plot new curves for dynamic and static data.

Dynamic Data

Dynamic data is plotted according to the scheme you define in the Dynamic Data section of the View Data tab. The following sample plots show Dynamic Stiffness versus Frequency for various amplitudes for the FX direction:
Figure 1.

The following are sample plots for Loss Angle versus Frequency for various amplitudes for the FX direction.
Figure 2.

Static Data

Following are two plots for static data. Each plot contains three curves: the red curve indicates experimental data, the blue curve indicates the conceptual cubic, synthesized from the static data, and the black curve indicates constant stiffness.

The following plot shows the Force versus Displacement behavior for the three curves:
Figure 3.

The following plot shows the Stiffness versus Displacement behavior of the bushing.
Figure 4.