Standard DIC analysis produces displacement and strain data in Cartesian (x, y, z) coordinates. This works well for many applications, but certain geometries and loading conditions are better understood in alternative coordinate systems.

For turbine blades, flywheels, brake rotors, and other rotating machinery, understanding radial versus tangential behavior is critical. A displacement that appears as a complex combination of X and Y components in Cartesian coordinates becomes a clear radial expansion or tangential shift in polar coordinates.

Pressure vessels, pipes, and O-ring seals naturally deform in radial patterns. Analyzing hoop strain (tangential) separately from radial strain provides direct insight into material behavior and failure modes that would be obscured in Cartesian representation.

Further, the stress field around circular holes follows polar patterns. Expressing strain in polar coordinates aligns your measurements with analytical solutions and textbook formulas, making validation and comparison straightforward.

To demonstrate the use of the Polar Coordinate extension in VIC-3D 11, we devised a simple test using a speckled ring printed on a piece of paper variously crinkled over 5 images. To follow along, download the test images and project file (containing calibration information) by clicking here: https://www.correlatedsolutions.com/downloads

Note: to use the Polar Coordinate extension and the other vicpyx extensions, Python must be installed. Click here for more information: https://www.correlatedsolutions.com/recent-news/python-dic-introducing-vicpyx

Please see other iris tutorials and our Visualizing DIC series for more details about the iris visualization workspace. https://www.youtube.com/watch?v=QVDga5aq3JA&list=PLKk1tDmnghhe4TrT-yJ-ZekksC1R2UCgq

If you have any questions about this document or any other questions, comments, or concerns about our software, please visit our website: https://www.correlatedsolutions.com/support

The powerful vicpyx feature is available exclusively in VIC-3D 11. Contact one of our Sales Engineers for information on updating your software. https://www.correlatedsolutions.com/contact