Fig. 2.

Renderings of a 2-mm-thick, longitudinal (x-z) section of the specimen in Fig. 1. Images taken at (a) 0% and (b) 2% compressive strain were used to generate longitudinal (c) and shear (d) strain images using DVC. The reconstructed distribution of secant modulus (e) shows a region of low modulus corresponding to the regions of high strain and of deformations large enough to be apparent to the eye (highlighted by a red circle). Secant modulus values are relative, rather than absolute, because no force data are used.