High-resolution in situ autonomous visual indication of mechanical damage is achieved through a microcapsule-based polymeric material system. Upon mechanical damage, ruptured microcapsules release a liquid indicator molecule. A sharp color change from light yellow to bright red is triggered when the liberated indicator 2',7'-dichlorofluorescein reacts with the polymeric coating matrix.

the main cause of structural damage in buildings subjected to seismic actions is lateral drift. in almost all reinforced concrete (rc) structures, whether designed with walls or frames, it is likely to be the code drift limits that control the design drift. the design drift limits and their contribution to damage may be represented indirectly through the material strain limits. the aim of this ...

The lay-up configuration (unidirectional, crossply and quasi-isotropic) and thickness (8–24 laminae) affect the damage self-sensing characteristics of continuous carbon fiber epoxy-matrix composites. The damage is by drop impact directed at the top surface of the laminate. The oblique resistance (i.e., resistance at an angle between the longitudinal and through-thickness directions) is an effec...

Damage progression tests were performed in the NASA Glenn Spiral Bevel Gear Fatigue Rig. Six gear sets with varying levels of tooth damage were tested, and vibration-based gear condition indicators, amount of debris generated, and oil temperatures were measured. The damage state was documented with photographs taken at inspection intervals throughout the test and was quantified with a numerical...