ETME360 Spring Semester 2014
E-Problem 9a
Ultrasonic Non-Destructive Testing at Elevated Temperatures 

R. Larson

1. The sonic velocities of a stainless steel specimen are measured in a laboratory test. The wave speeds are recorded and plotted versus temperatures, and a curve fit is obtained using the least squares method. The resulting relation is;

V = 2.7x10-4 *T2 - 0.54*T + 5806  meters/second, where V = wave velocity, and temperature T is in units of C

If the specimen has a coefficient of thermal expansion of α = 1.3x10-6 C-1, and has a thickness of 0..50 inches at room temperature (20C), 

 (A) find the longitudinal wave sonic velocity at room temperature.

(B) find the period (i.e. the distance between similar echo wave-front peaks of the oscilloscope display) for the specimen at room temperature of 20C,

(C) calculate expected period at temperatures of 500C, and 1000C. 

(D) find the thickness of the specimen at temperatures of 500C, and 1000C.