Model Correlation Utility

The Model Correlation Utility determines the degree of similarity or correlation between two sets of results.

nvh_model_correlation_main

Modal Assurance Criterion (MAC) is a measure of the correlation between two vibration shapes. Supported vibration shapes include:

•	Real modes – vibration data at each node is a scalar value.

•	Complex modes – vibration data at each node is a complex value.

•	Response animation or operational deflection shape - vibration data at each node is a complex value.

nvh_mac_equation

The vibration shape results, along with the finite element mesh of the structure, are assumed to come in one of the following result files:

•	H3D – binary result file typically generated using OptiStruct.

•	OP2 – binary result file typically generated using OptiStruct or Nastran.

•	ODB - binary result file typically generated using ABAQUS.

•	UNV – ASCII result file typically exported from a testing software.

Typically, the model that has less nodes, such as a test model, is used as the reference model.

To access the Model Correlation utility, you must register the NVH preferences file and load the NVH Utilities. See the NVH Menu topic for more information.

1.	From the NVH menu, select Model Correlation.

nvh_menu_model_correlation

NVH menu

An NVH-Utilities tab is added to the browser. This browser tab contains the Load tab. It also contains icons for other utilities, such as modal participation, , and order cut analysis, . Select an icon to toggle between the utilities.

nvh_mac_ex_file

NVH-Utilities Browser - Load tab (Model Correlation)

2.	To close the NVH-Utilities tab, click the X in the upper-right corner of the dialog.