SMART STRUCTURAL COMPOSITES WITH MONOFILAMENT, PIEZOELECTRIC SENSORS

Smart materials or structures have embedded sensors to monitor their o wn state as well as environmental stimuli. A novel sensor was develope d by sputtering a piezoelectric film onto a conductive fiber or metal wire. This sensor, similar in configuration to an optical fiber, is ac tive since an electric field is developed when strained. Several of th ese sensors were embedded into a cantilevered beam and a filament-woun d cylinder made from AS4/ Epon 828 composites. A variety of test cases were used to demonstrate its sensing feasibility, including free and forced vibrations and acoustic emissions.