| Summary: | 碩士 === 國立臺灣大學 === 應用力學研究所 === 82 === Surface waves will disperse as propagating on layered medium
because of geometry and boundary condition.The dis- persion
relation also relate to the material properties. So,Ultrasonic
techniques are very widely used in measuring and in non-
destructive evaluation.For examples,the coating of the electric
device or geotechnical engineering. First we derivate the
iteration formula,to compuate the dispersion relation of
layered anisotropic materials.Further we use this method of
evaluation combining with acousto- elasticity to solve the
dispersion due to residual stress. In experiment,we use laser
as source of the elastic wave and use NBS conical transducer to
recive the singnal of displacement. And use the spectral
analysis of surface waves method to measure and compuate the
dispersion relation of tesing material (Cu plate on Al block).
Final we discuss the difference between the experimental and
therial data.
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