Waves and vibrations in elastic superlattice composites

Thesis/Dissertation · Thu Jan 01 00:00:00 EST 1987

OSTI ID:7202138

Wang, Y

The composite materials considered here are periodic arrays of piezoelectric elements in a nonpiezoelectric matrix with different elastic properties. From Bloch-wave theory it is know that the Bragg reflection of space harmonics generate stopbands in an elastic superlattice. Piezoceramic-plastic composites have very wide stopbands in the propagation characteristics because the impedances are very different for the two phases of the composites. These lateral stopbands play an important role in reducing crosstalk between image-array elements, as well as eliminating lateral transducer resonances. Good design requires placement of resonances at the stopband edges of the periodic elastic superlattice so they will not interfere with the desired thickness resonance. Elastic Bloch wave theory for these elastic superlattices was used to explain the mechanical properties of the composite. An infinite sum of vector space harmonics is the solution of acoustic wave propagation in the unbounded periodic composite. Other methods for solving wave propagating in elastic superlattice media, and comparisons between different methods, are been discussed. Measurements were performed on composite-plate transducers to test the accuracy of the theory.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 7202138
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
47 OTHER INSTRUMENTATION
COMPOSITE MATERIALS
MECHANICAL PROPERTIES
SUPERLATTICES
LATTICE VIBRATIONS
PIEZOELECTRICITY
PLASTICS
TRANSDUCERS
WAVE PROPAGATION
ELECTRICITY
MATERIALS
PETROCHEMICALS
PETROLEUM PRODUCTS
SYNTHETIC MATERIALS
360603* - Materials- Properties
440300 - Miscellaneous Instruments- (-1989)