Mechanical APDL Basic Analysis Guide - Ansys

Chapter 3: Using the Function Tool
The Function Tool allows you to define a dependent variable as a function of one or more independent
variables. Using the Function Tool, you can define complicated boundary conditions on a model, or you can
define the nonlinear material behavior for a joint element.
Example 1 Suppose that the applied displacement at a node of the model is a function of temperature
and velocity. The function is defined as follows:
u = (-0.007 * T + 0.50) V r
where T is the temperature and V r is the relative velocity.
The Function Tool allows you to input the function, thereby specifying the boundary condition at that node.
Example 2 Suppose the nonlinear damping force characteristics in a joint element varies quadratically
with temperature and linearly with velocity. The function is defined as follows:
F = f(T) V r
or
F = (C 1T 2 + C 2T + C 3) V r
where C 1, C 2, and C 3 are constants, T is the temperature, and V r is the relative velocity.
The Function Tool allows you to input the function along with the constant values, thereby incorporating
the damping characteristics by specifying a nonlinear force that varies with relative velocity and temperature.
The following Function Tool topics are available:
3.1. Function Tool Terminology
3.2. Using the Function Editor
3.3. Using the Function Loader
3.4. Applying Boundary Conditions Using the Function Tool
3.5. Function Tool Example
3.6. Graphing or Listing a Function
For more information, see Specifying a Function Describing Nonlinear Stiffness Behavior in the Element Reference.
3.1. Function Tool Terminology
The Function Tool has two components:
• Function Editor -- Creates functions.
• Function Loader -- Retrieves the functions and loads them as table arrays.
The following terms apply when using the Function Tool:
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