The plates may be {HEAD ~ actuators}, which couple energy into the attached structure, or sensors which respond to {TAIL ~ strain} coupled from the attached structure 
The plates may be { HEAD ~ actuators } , which couple energy into the attached structure , or sensors which respond to { TAIL ~ strain } coupled from the attached structure
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH