PASSIVELY DAMPED STRUCTURAL COMPOSITE-MATERIALS USING RESISTIVELY SHUNTED PIEZOCERAMIC FIBERS

The development of damped structural materials is an area of current r esearch with potential for high rewards. Resistively shunted piezocera mic fibers used as reinforcement in a structural composite material of fer the potential to significantly increase vibration damping capabili ty. Available data indicate the predictable nature of this electroelas tic damping mechanism, an important concern in design. This article ad dresses the current status of an effort to develop damped composites u sing resistively shunted piezoceramic fibers, including modeling aspec ts, performance limits, design guidelines, and fabrication issues. Ini tial design guidelines take the form of a modified modal strain energy method. With longitudinally poled fibers, peak damping loss factors o f 12% are attainable in principle, even at relatively low (30%) piezoc eramic fiber volume fractions. Some 30-mu m diameter piezoelectric fib ers have been produced using a sol-gel method, and details of poling a nd shunting are under investigation.