METHOD OF DETECTING DEFECTS IN STRUCTURE OF COMPONENTS Russian patent published in 2010 - IPC G01N29/14 

FIELD: physics.

SUBSTANCE: two equilateral triangles having side 1 with length shorter than 60 mm are placed on a component. The triangles are placed in a single plane and their bases are on a single line. The analysed space is placed on the extension of the plane of the triangles. Signal receivers AE are placed on vertices of the triangles. Time lag values t₁, t₂ and t₃ for arrival of a signal from the source AE to the receivers are measured. The time lag values t₁, t₂ and t₃ for arrival of the front of the signal from AE at the vertices of triangle vary in accordance with the following expression: t₁=(l/υ)·sin(60°+φ), t₂=(l/υ)·sinφ, t₃=(l/υ)·sin(60°-φ), where φ is an angle measured anticlockwise between the bisector of the angle and direction of the defect, passing through the centre of the triangle. Angles φ₁ and <φ₁', which characterise the direction of the defect for the first and second triangle are determined using the formula φ₁(φ₁')=arcsin(t₂/T), where T=l/υ is time for which sound passes through the component at distance equal to l, and t₂ is the least time lag in each triangle. The point of intersection of directions which characterises the position of the defect in the component is determined.

EFFECT: increased accuracy and efficiency of determining position of defects during manufacture and use of components.

3 dwg