Ko. Prakahasante et Kc. Craig, ACTIVE CONTROL OF WAVE-TYPE VIBRATION ENERGY FOR IMPROVED STRUCTURAL RELIABILITY, Applied Acoustics, 46(2), 1995, pp. 175-195
Degradation of the structural integrity of flexible, composite structu
res occurs over time when subjected to vibratory disturbances. Active
vibration control methods present a way to minimize vibration levels i
n structures for improved structural reliability. Control architecture
s which have been developed and specialized for vibration reduction in
flexible structures are presented. These are based on the interpretat
ion of vibration behavior in the form of waveform propagation and moda
l response. To reduce the potential energy of a structure with vibrati
on characteristics dominated by standing waves, a nonlinear rate-feedb
ack scheme and a dual-controller scheme for both transient and steady-
state vibration minimization have been developed. Vibration in flexibl
e structures may also be dominated by travelling waves with standing w
ave components superimposed. A new concept, the total energy absorptio
n (TEA) compensator, allows control of stationary and propagating wave
forms in flexible structures based on feedback of wave-type energy-fie
ld measurements. The TEA formulation considers vibration energy-fields
in the structure in the form of complex intensity and energy density
for effective vibration minimization. Lightweight piezoelectric materi
als and accelerometers are used as sensors to estimate the energy-fiel
d parameters. Piezoelectric materials are used as distributed actuator
s to drive the flexible structure. Numerical and experimental results
on the reduction of the total vibrational energy in flexible structure
s using these active control methods are presented.