The interferometric strain/slope rosette (ISSR) is further developed to include greater capabilities of measuring multiple strains in isotropic and anisotropic materials. The method is being developed as a quasi-nondestructive method of evaluating residual stresses. ISSR indentations are also used to record permanent deformations incurred from manufacturing processes, which offers industries a quality control tool to avoid failures due to excessive residual stresses. Fatigue and fracture behavior of materials is investigated through an integrated experimental-theoretical numerical approach. A new diffraction strain gage/rosette technique is also developed to allow measurements in soft materials. Applications include bioengineering materials such as tissues, and thin-thickness polymer materials.
