Improved Method of Contact Pressure Measurement by Means of Ultrasonic Waves.

The contact pressure measurement in jointed plates is investigated by means of an improved ultrasonic technique. At first, the relations between the contact pressure and the bottom echo height measured using a normal probe, when the boundary echo height is kept constant, are obtained by compressing calibration blocks under various surface roughnesses. Next, two rectangular plates and two disks with a circular hole are compressed under locally uniform pressure, and the bottom echo height, when the boundary echo height is kept constant, is measured using the normal probe. From the relations between the calibrated and measured curves, the contact pressure distribution in the jointed plates is quantitatively obtained. The experimental results agree fairly well with the analytical ones. Thus, the proposed ultrasonic method is useful for the measurement of contact pressure.