Load Path Stiffness Editor

The load path stiffness parameters compensate for the amount of deflection that is produced from the actuator, through the grips, extension rods, load cell, and load frame (everything in the load path except the specimen). All of these components act together as the load path.

Any unique combination of the components of the load path should have a stiffness set defined for them.

File Menu

Lists the file management selections.

Current Set

Displays the name of the current control parameters set.

Description area

The middle part of the window displays a description of the current load path stiffness set. You can also type into this area.

Input Signals

The lower part of the window displays a list of TestStar input signals. Highlight each input that you want to define a stiffness value.

Define Stiffness

Displays the Define Stiffness window  where you assign a stiffness value to each selected input signal.

More Information

See determining stiffness  and using the editor  for procedures.

See Appendix F in the 790.01 TestStar Reference manual for detailed information about the Load Path Stiffness Editor.


File Menu

New

Creates a new load path stiffness set based on the current (open) set and displays <new> as the Current Set.

Open

Displays the Open window  where you can open a predefined load path stiffness set.

Save

Saves the current load path stiffness set. Displays the Save window  if you are saving a new set.

Save as

Displays the Save window  where you can name the load path stiffness set and specify where it is to be saved.

Delete

Displays the Delete window  where you can select a control load path stiffness set and remove it from the data base.

Print Preview

Displays the Print Preview window where you can review a list of all the current load path stiffness settings.

Print

Prints a list of all the current load path stiffness settings.

Print to File

Saves a copy of all the current load path stiffness settings as an ASCII file.

Print Setup

Displays a window where you can configure your printer.

Global Default

Displays the Global Default window  where you can select a load path stiffness set as the default set. The default set is used whenever the Load Path Stiffness Editor is opened.

Exit

Closes the Load Path Stiffness Editor.


New

Creates a new load path stiffness set based on the current (open) set. The name of a new set is called <new>.


Open

Use this window to open a load path stiffness set.

Select a load path stiffness set from those listed.

Press the OK pushbutton to open the selection. stiffness set.


Save

Saves the current load path stiffness set.

If the current stiffness set is named <new>, the Save window  opens so you can name the load path stiffness set.


Save As

Use this window to name a load path stiffness set.

Type a name in the entry field at the top of the window.

Press the OK pushbutton to save the default load path stiffness set.


Delete

Use this window to delete a load path stiffness settings file.

Select a load path stiffness set form those listed.

Press the OK pushbutton to delete selection.


Print

Prints the current load path stiffness settings to the printer defined in the Print Setup window. The information that is printed is the same information available in the Print Preview window.


Print Preview

This window lists all of the load path stiffness values of the current set.

This window has a File menu that duplicates the print functions listed in the Load Path Stiffness Editor's File menu .


Print to File

Use this window to create a text file of the load path stiffness set. Use this window to name the file and define a path to its location.

Select a drive and directory (or subdirectory) where you want to save the file.

Type a name in the Filename entry field.


Printer Setup

Use this window to select a printer and set up the preferences for the printer. Press the Options pushbutton to see the preferences you can assign to the selected printer.


Global Default

Use this window to assign a load path stiffness set as the default setting file. The default stiffness set is used whenever you open the editor.

Select a load path stiffness set from those listed.

Press the OK pushbutton to assign the selection as the default load path stiffness set.


Define Stiffness Window

Use this window to assign stiffness values to specific input signals. Before you can use this window you must determine the stiffness values .

Input

Selects one of the input signals that were highlighted in the main editor window.

Linear/Angular

Indicates if the selected input signal is from an axial or torsional control channel. When a strain signal is selected the control is active so you can set the Linear/Angular channel.

Stiffness

Select the stiffness units with the right entry field, then type the stiffness value in the left entry field.

Using the window

1	Select an input signal in the Define Stiffness window.

2	Select the stiffness units then enter the stiffness value.

3	Repeat steps 1 and 2 for each input signal.

4	Press OK in the Define Stiffness window.


Determining Stiffness

The following is a guideline to determine the stiffness value for an axis. Be sure to have the load path configured with components needed for the test.

Create a test command program that produces a slow ramp (one minute) over the range of the force sensor.

Acquire force and displacement data.

Use a stiff specimen such as steel.

Calculate the stiffness from the force and displacement data.

The acquired data can be used with a spread sheet application to calculate the stiffness value (or slope of the data.)


Using the Editor

1	Select New  in the File menu.

2	Select the input signals that will have load path stiffness values.

3	Press the Define Stiffness pushbutton to display the Define Stiffness window .

4	Select an input signal in the Define Stiffness window. If you select a strain signal, set the Linear/Angular control so the proper dimension is used.

5	Select the stiffness units then enter the stiffness value.

6	Press OK in the Define Stiffness window.

7	Type a description for the stiffness set in the entry area of the Load Path Stiffness Editor window .

8	Select Save As  in the File menu. Type a name for the stiffness set in the entry field and Press OK.