An Experimental Determination of Ultrasonic Longitudinal Wave Velocities Through Nose Cone Materials at Several Temperatures as a Function of Lamination Angle

摘要

Ultrasonic longitudinal wave velocities of nose cone materials were measured as a function of the lamination angle at several temperatures between 25C and 125C. Wave velocity at 3 Mc was obtained by measuring directly the transit time through a sample and dividing into the measured sample thickness. A maximum wave velocity uncertainty of 1.5% was obtained. It was found that the longitudinal wave velocity vs lamination angle curve maintains the same shape (for a given material) for temperatures between 25C and 125C. Furthermore, it was found that the wave velocity vs lamination angle curve can be predicted to within 2 1/2% by an empirical equation involving only the lamination angle; c(0 degrees), the measured wave velocity at an angle of 0 degrees; and c(90 degrees), the measured wave velocity at an angle of 90 degrees. Finally, it was found that the longitudinal wave velocity of certain materials varies as much as 25% between lamination angles of 0 degrees and 90 degrees, while other materials show less or no variation at all. (Author)