# Specifying potential terms

 Connector potentials are user-defined mathematical functions that represent yield surfaces, limiting surfaces, or magnitude measures in the space spanned by components of relative motion in a connector. You use potentials to define coupled friction, plasticity, or damage behavior options. For more information, see Connector functions for coupled behavior.
 Related Topics Defining friction Defining plasticity Defining damage Specifying connector derived components

Context:

To display context-sensitive help for options in the potential contribution editor, you must select the option of interest and then press F1. (The Help menu in the main menu bar is unavailable while the editor is displayed.)

1. Display the potential tabbed page.

• For friction behavior, use the procedure outlined in Defining friction, to display the Force Potential tabbed page.

• For plasticity behavior, use the procedure outlined in Defining plasticity, to display the Force Potential tabbed page.

• For damage behavior, use the procedures outlined in Defining damage, and Defining damage evolution, to display the Initiation Potential and Evolution Potential tabbed pages.

2. Choose the Operator.

Sum

Define the potential as the sum of the contributions.

Maximum

Define the potential as the contribution that yields the maximum value.

3. If you selected Sum in the Operator field, enter a positive value in the Exponent field to specify the inverse of the overall exponent in the potential definition, $β$, that defines a general elliptical form of the potential. The default value of 2 defines a quadratic form of the potential.

4. In the Potential Contributions portion of the tabbed page, select one of the following options:

• To define a contribution to the potential, $Pi$, click .

The potential contribution editor appears.

• To edit an existing contribution, select a contribution from the list, and click .

The potential contribution editor appears.

• To delete an existing contribution, select a contribution from the list, and click .

5. In the potential contribution editor, do the following:

1. Specify the component to use in the potential contribution.

Specify component

Choose an available component of relative motion to define the potential contribution.

Specify derived component

Click to specify a connector derived component to define the potential contribution. For more information, see Specifying connector derived components.

2. Choose the Sign.

Positive

Select a positive sign for the potential contribution.

Negative

Select a negative sign for the potential contribution.

3. Enter the following data:

Scaling factor

Enter the nonzero scaling factor R. The default value is 1.

Positive exponent

Enter a value for the positive exponent $α$. The positive exponent value is ignored if you selected Maximum in the Operator field.

Shift factor

Enter the shift factor a. The default value is 0.

H-function

Select the function H to be used to generate the contribution. The default value is ABS.

• ABS. Use the absolute value function to generate the contribution.

• MACAULEY. Use the Macauley bracket () to generate the contribution.

• IDENTITY. Select the identity function only if the following is true:

• Positive exponent ($α$) = Exponent ($β$) = 1