An experimental micromechanics measurement technique for submicrometre domains

Abstract

Orthogonal arrays of dots applied to surfaces can be used to directly measure microscopic strain fields. The spatial and strain resolution are both limited by the size of the dots placed on the surface. Two techniques using the beam of a scanning electron microscope (SEM) have been developed which make possible the placement of very fine dots with diameters of only 0.5 and 0.02 μm, respectively, on the surface of the specimen, allowing local strain measurements on the scale of 0.2–10 μm when specimens are loaded in the SEM. Measurements of strains fields around the tips of growing cracks in both polymers and polymeric composites are presented to illustrate the capabilities of the technique.