Method and device for measuring permanent length deformations of materials

摘要

A method for measuring permanent length deformations in materials includes determining a change of an initial distance between two measuring points on the material surface. A first pair of impressions is formed on a portable impression body that corresponds to these two measuring points prior to the expected deformation and a second pair of impressions is formed after a critical loading of the material. The distances between the first and the second pairs of impressions are then compared. A device for carrying out the method uses a fixed portion arranged on the material being measured and a portable impression body. The fixed portion of the device is provided with a pair of measuring elements which correspond to the measuring points disposed at a mutual distance from each other, and the portable impression body of the device has an impression face adapted for receiving the impressions that are created by the measuring elements.