The group focuses on the experimental definition or verification of the response of materials, structures and mechanical systems. Primary emphasis is placed on physical measurements using techniques such as photomechanics (holography, moire techniques, two- and three-dimensional photoelasticity, and speckle interferometry), electrical resistance strain gauges, piezo-sensors, differential transformers, and proximity indicators. Three labs are devoted to photomechanics, with precision optical components, isolation benches, lasers, moire printing facilities, high-speed cameras, digital imaging systems, and a variety of load frames. Dynamic structural and mechanical system studies are facilitated by two labs with equipment available for high-speed data acquisition, spectral analysis, shakers and shock tables, multiaxes controllers, digital signal processing, and modal analysis modeling and verification. Experimental stress analysis facilities support the use of brittle coatings; application, signal conditioning and automated data reduction from electrical resistance and piezoelectric strain gauges; and photoelastic analysis with slice analyzing, transmission and reflection polariscopes. Current research efforts deal with the broad areas of dynamic structural response of prestressed structures, material property definition for composite and fibrous materials, and fracture investigations of composite materials.