METHOD MEASURING MECHANICAL STRESS IN STRUCTURAL MATERIALS Russian patent published in 2002 - IPC

FIELD: nondestructive test of physical characteristics of structural materials, determination of single-axis mechanical stresses of various structures in field, for instance, pipe-lines delivering oil and gas. SUBSTANCE: ultrasonic pulses of shear volume waves are excited in tested zone, they propagate perpendicular to plane in which stress exists and are polarized criss-cross line of stress action. Passed pulses are received, value of shear anisotropy is computed. Then radiator-receiver of Rayleigh surface waves is placed in tested zone instead of shear volume wave transducer, ultrasonic pulses of Rayleigh surface waves are excited criss-cross line of action of stresses, pulses passed through tested zone of object are received, value of Rayleigh anisotropy is calculated, value of shear anisotropy corresponding to unloaded state of material in measurement zone is calculated. Later mechanical stress active over tested section is computed. EFFECT: enhanced authenticity of measurement of single-axis mechanical stresses in structural materials by generation of reliable information on initial state ( initial stresses ) of material in tested zone, reduced labor input and expenses. 1 cl, 3 dwg