FIELD: test equipment.SUBSTANCE: invention relates to a testing technique and can be used to evaluate the performance of metals in a structure. It is performed the sample with a crack or with a stress concentrator, where the load application axis and the action axis of the spacer bolt are spaced, fixation by a spacer bolt of a given deformation on a sample with a crack or with a stress concentrator and subsequent exposure of the loaded sample. After the sample with a spacer bolt is exposed, a crack opening sensor is mounted on the sample, then an external load is applied and a crack opening detection force is determined by the crack opening sensor, and stress relaxation at the tip of the crack is defined as the difference between the initially established load on the sample and the crack initiation force or the compression force on the sample with the concentrator acting in the sample after exposure.EFFECT: possibility to determine the stress relaxation at the tip of a crack or a voltage concentrator of room
