Results Math

In this section, you will learn how to use the Derived Results Expression Builder to perform mathematical operations on results. To access the Derived Results Expression Builder you can do one of the following:

• Select the Derived Results button, on the Results toolbar

• Right click in the Results Browser or Graphics Area and select Create > Derived Results

The Expression Builder is a graphical user interface which allows user-defined data type expressions to be authored directly within HyperWorks Desktop. These expressions use a simplified Templex-style syntax that gets parsed into XML statements which are then passed on to the Result Module for processing.

In the Expression Builder there are 3 basic areas; the Output parameters, the Operator and Table selection, and the Expression Text. These 3 areas are highlighted below and each section is discussed.

Within the Output parameters area, the Label field is used to enter a name for the new derived result. This name will appear in the Results Browser in the appropriate Scalar, Tensor, or Vector folder. The Output can be defined for all load cases, or restricted to the current one.

Within the Operator and Table selection area, the Operator field contains a list of available operators and is controlled by the template file selected when loading the model and result. The operator list is broken down by library, and when selected, will update the help section with a description and the argument list. Double-clicking an operator will add it to the expression text area. This is different than the Table parameter arguments that have to be added using the Insert button. If an argument has a default value, it will be entered into the expression text area. All other arguments must be specified by selecting tables and entering them in the appropriate argument. Additional information regarding the various operators (description, syntax, arguments, etc.) can be displayed by clicking the Show operator help drop-down arrow.

Once an operator is selected, tables must be selected to form the input. The table selection portion of the dialog lists all of the tables available, and optionally extended selection drop-downs to enable a table to be addressed from another frame, load case, or even from a different resource. Click on the Show all drop-down arrow to display the full list of table options. For additional information on the Expression Builder, please refer to the Online Help.

Finally the Expression Text is entered. This is the actual expression to be evaluated for the new data type. Operators and Tables are inserted and added to this field, as well as additional text to complete the expression.

The example below shows the Expression Builder with a simple math operation. Using the Expression Builder, the Stress Amplitude can be calculated. This is done by taking the absolute value of the difference of the P1 Major stress minus the P3 Minor stress and dividing by 2. Below is also an image of the Results Browser showing the Stress Amplitude listed as a Scalar value.