Damped structural composite material using resistively-shunted piezoelectric ceramic short fibers

The development of damped structural materials is an area of current research with potential for high payoff. Resistively-shunted piezoceramic fibers used as reinforcement in a structural composite material offer the potential to significantly increase vibration damping capability. This paper addresses the current status of an effort to develop such damped composite materials, including modeling aspects, performance limits, design guidelines, and fabrication issues. With longitudinally-poled fibers, peak damping loss factors of 12% are theoretically attainable, even at low (30%) piezoceramic fiber volume fractions. Relatively short fibers could provide composite stiffness and damping nearly equal to that provided by continuous fibers, with some fabrication and cost advantage. Some piezoelectric fibers have been produced using a sol-gel method, while details of poling and shunting are under investigation.