A stress field measurement method based on ultrasonic tomography

Abstract

The invention provides a stress field measurement method based on ultrasonic tomography, which belongs to the technical field of ultrasonic nondestructive testing. The method includes the steps of: calibration test; determination of projection coefficient matrix; zero stress reference acquisition, sequentially exciting each ultrasonic transducer in the ultrasonic transducer array to obtain a zero waveform data set; measurement data acquisition, collected according to the zero stress reference The excitation sequence excites each ultrasonic transducer in the ultrasonic transducer array in turn to obtain the test waveform data set; time delay calculation, using the cross-correlation algorithm to solve the corresponding stress time delay vector; solving the stress field equation, using tomography The algorithm solves the stress field equation to obtain the stress vector; draws the stress field image according to the stress vector. The invention is based on an ultrasonic tomography algorithm, and by constructing a probe scanning matrix, the stress field distribution on the shallow surface of the workpiece can be obtained in a single measurement without moving the probe, reducing the requirements for operators and improving the measurement efficiency.

Description

technical field [0001] The invention relates to a stress field measurement method based on ultrasonic tomography, belonging to the technical field of ultrasonic nondestructive testing. Background technique [0002] The material will inevitably produce plastic strain during the mechanical manufacturing process, resulting in residual stress. At the same time, during the service process of the workpiece, the interior of the workpiece is affected by aging or external loads, and the stress will change. Measuring the surface stress of the workpiece can not only provide data support for the safety evaluation of the structural service, but also improve the production process and component processing methods on this basis to further extend the service life of the workpiece and reduce production and operation costs. [0003] There are many kinds of stress detection technologies in objects, which can be subdivided into three categories according to whether the detected object is damage...

AI Technical Summary

Problems solved by technology

At the same time, the existing ultrasonic residual stress measurement technology adopts single-point measurement. To realize the stress distribution measurement on the shallow surface of the workpiece, a mechanical device is often used to move the measurement probe to realize the measurement of different measurement points. The quality of the operator is required to be high, so the rapid and non-destructive measurement of the stress field distribution on the shallow surface of the workpiece has great engineering application value

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