STRAIN CALCULATION IN VIC-3D
The strain calculation in Vic-3D is similar to the algorithm generally used by FEA software. The input for the strain
calculation is the grid of data points from the correlation ā a cloud of X, Y, Z points and U, V, W displacement vectors.
The separation between these points (in pixels) is dictated by the step size. The separation between the points in physical
space will vary depending on magnification and the shape of the specimen.
With this grid as the input, we consider each point separately, and create a local mesh of triangles; here, we consider the
highlighted point from above:
Next, we consider each triangle separately: