Back-solving to derive a parameter value          

In this lesson, you’ll learn how to back-solve from a computed variable to derive the value of a dimensional parameter. Continuing to work with the file we used in the previous lessons, Adding Equations to a Model and Tolerance Analysis, we’ll solve for the beam height that will produce a specific stress level. You will also learn how to add text to your sketch, which is particularly useful for sharing information about a model with other team members.

Back-solve to drive the beam height

  1. In the Math view’s parameter table, unlock the h dimension by clicking on the lock symbol in the L (Lock Status) column.

  2. Observe that the values of the S, c, and Ix variables also become unlocked. If we review the equations, we see that this occurs because these variables are interdependent. Entering a value for one of these variables (and thereby locking that variable) will drive the values of the other variables.
  3. To drive the values with the stress (S) variable, change the value of S to 10000, and press Enter to accept the change.

    The status for S becomes locked. The variables that are now driven by the value of S (h, c, and Ix) are changed to derived status, and their values are recalculated based on the value for S.

    Observe in the Sketch view that the height of the beam has changed in response to the new value of S, which now drives the beam height.

    Beam height

Add text to the sketch

In this part of the lesson, we'll add a note to the sketch to tell other team members that we used equations to find the height of the beam.

  1. Select the Sketch Text tool from the Sketch view toolbar.
  2. Select the line that has its height set by the h dimension.

    Select line
  3. In the Sketch Text dialog that appears, type the text shown in the following illustration, then click OK. (Note: If you do not select an object when placing the Sketch Text, you will not have options to show a leader line or move the text with the object.)

    Sketch Text entry
  4. If needed, zoom out or pan to see the text in its entirety.
  5. Move the text as desired by clicking and dragging it using the Select tool. (You can return to the Select tool at any time by pressing Esc on your keyboard.)

    Sketch text
  6. Click on the text to see its properties in the Properties Explorer. To better format the text, add line breaks by pressing Enter to break the lines as shown in the following illustration.

    Format sketch text

    The text now appears as shown below.

    Position text

Congratulations! You have successfully completed the Equations tutorial.

For extra practice, work through the attached labs that explore additional methods of computing beam stress.