GB/Z 45378-2025Non-destructive testing - Methods for absolute calibration of acoustic emission transducers by the reciprocity technique (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting.

This document is modified to adopt ISO /T R13115.2011 "Absolute calibration method for acoustic emission sensors based on reciprocity technology for non-destructive testing" The document type was adjusted from ISO 's technical report to my country's national standardization guidance technical document.

Compared with ISO /T R13115.2011, this document has made the following structural adjustments.

--- 5.2~5.4 in Chapter 5 correspond to 5.1~5.3 in Chapter 5 of ISO /T R13115.2011, with 5.1 added;

--- 6.2~6.4 in Chapter 6 correspond to 6.1~6.3 in Chapter 6 of ISO /T R13115.2011, with 6.1 added;

--- 7.2~7.5 in Chapter 7 correspond to 7.1~7.4 in Chapter 7 of ISO /T R13115.2011, with 7.1 added. The following editorial changes were made to this document.

---Change the unit of burst signal period T from "s" to "ms" (see the unit in Figure 1);

---Change "|I'R(f)|" in 6.3.2 to "|I'L(f)|", and change "|U'R(f)|" to "|U'L(f)|".

Introduction

The first-level calibration method for acoustic emission sensors is ISO 12713:1998[1], which introduces the vibration surface pulse method using Rayleigh surface waves for calibration.

The glass capillary fracture is used as the sound source, and the dynamic displacement of the surface is measured using a standard capacitive sensor.

According to ISO 12714:1999[2], the receiving sensitivity of the calibrated sensor is measured comparatively using the vibrating surface pulse method.

This document describes a method for calibrating the absolute sensitivity of acoustic emission sensors using Rayleigh surface waves and longitudinal waves by means of the reciprocity technique.

Since the reciprocity parameters have been derived, the absolute sensitivity can be determined by purely electrical measurements without the use of a mechanical sound source or a reference sensor.

The operating procedures of the vibrating surface pulse method and the reciprocity technique are different, but the two calibration methods have a common theoretical basis.

The vibration surface pulse method, in theory, calculates the surface displacement based on the Lamb wave theory (reference [7]), while for the reciprocity calibration method, the Rayleigh The reciprocity parameters of the wave calibration also come from the Lamb wave theory. For Rayleigh surface wave calibration, the cyclic test has been carried out and it has been determined that the The absolute sensitivities obtained by the two methods are in good agreement.

The purpose of both methods is the same, which is to establish the consistency of acoustic emission testing to form a basis for data correlation and to provide a basis for different laboratories to compare different Provide interpretation of acoustic emission test results obtained over time.

This document introduces the methods of three-sensor calibration, two-sensor calibration and pulse response calibration.

The three acoustic emission sensors prepared are all reversible sensors of the same type, configured as three pairs of independent emission sensors on the solid transmission medium.

Each pair of sensors measures the transmitted signal current and received signal voltage as a function of frequency and determines the The absolute sensitivity amplitude of Rayleigh surface waves and longitudinal waves is the frequency response. The acoustic emission sensor calibrated by three sensors can be used as an acoustic emission sensor.

The radiating or receiving sensor can be used to calibrate any one of the sensors to be calibrated by a relatively simple procedure.

The absolute receiving sensitivity of the acoustic emission sensor to be calibrated is determined by using a sensor whose emission current response has been calibrated by the three-sensor calibration method.

In addition, the impulse response of each acoustic emission sensor can be determined by three-sensor calibration.

In the calibration, the absolute sensitivity amplitude and phase frequency are obtained by three-sensor calibration based on the reciprocity parameter in complex form.

The impulse response is determined by performing an inverse Fourier transform on the frequency response.

1 Scope

This paper describes the calibration of the absolute sensitivity frequency of three reversible acoustic emission sensors of the same type using the reciprocity technique. Three-sensor calibration method for rate response.

This document describes the use of sensors whose emission current responses have been obtained using a three-sensor calibration method to determine the acoustic emission sensor to be calibrated.

Dual sensor calibration method based on absolute sensitivity amplitude-frequency response of sensors.

This document describes how to calibrate the sensors by measuring the frequency response using a three-sensor calibration method and then performing an inverse Fourier transform.

The absolute sensitivity pulse response of the sensor is used to express the calibration result.

2 Normative references

The contents of the following documents constitute essential clauses of this document through normative references in this document.

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to this document.

GB/T 12604.4-2005 Non-destructive testing terminology Acoustic emission testing (ISO 12716:2001, IDT)

3 Terms and definitions

The terms and definitions defined in GB/T 12604.4-2005 and the following apply to this document.