FIELD: nondestructive methods of diagnostics of materials of structures. SUBSTANCE: method can be used for determination of actual stressed-deformed state of previously tightened bolted joints in structures of operated objects of vital assignment in various branches of industry and transport such as heat power and atomic power engineering, mechanical engineering, chemistry and so on. It consists in induction of ultrasonic oscillations on frequency of main resonance of standing wave into tested tightened bolt. Amplitude of exciting oscillations is set at level ensuring wave of low intensity in body of bolt. Then amplitude of exciting oscillations is set at level providing establishment of amplitude of standing wave on boundary of oscillations of low and terminal intensities. Amplitudes of first, second and third harmonics are measured and stressed-deformed state of material of bolt and value of mechanical stresses are judged by relations of amplitudes of harmonics measured at high level of exciting oscillations to amplitude of oscillations of standing wave measured at low level of exciting oscillations. Parameters of induced continuous ultrasonic oscillations are calculated by special formulas. EFFECT: expanded application field of method. 2 cl, 3 dwg
