Evaluation of the effect of flatness on the contact pressure distribution between jointed plates by means of ultrasonic techniques.

Abstract

A contact pressure distribution in jointed plates has been investigated by using an ultrasonic technique, especially by varying the flatness of joint surfaces. At first, the relations between contact pressure and sound pressure of reflected waves by using a normal probe and angle probes are obtained by compressing calibration blocks under various surface roughnesses. Next, when two rectangular plates and two disks with a circular hole are compressed under various convex flatnesses of the joint surfaces, the sound pressure of reflected waves is measured by the normal probe or the angle probes. From these relations, the contact pressure distribution in these jointed plates is quantitatively assesed. The experimental results are presented graphically and compared with an analytical one. It is clarified that the contact pressure distribution is influenced significantly by the very small flatness deviation, thus the proposed ultrasonic method is practically useful for the measurement of contact pressure.