GB/T 31211-2014Non-destructive testing - Ultrasonic guided-wave testing - Part 1: General principle (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 part 1 of GB/T 31211 Non-destructive testing - ultrasonic guided wave testing: GB/T 31211 has been published for the following part:

--- Part 1: General;

--- Part 2: Magnetostriction method:

This document replaces GB/T 31211-2014 "General principles for non-destructive testing of ultrasonic guided waves": Compared with GB/T 31211-2014, except for structural in addition to adjustments and editorial changes, the main technical changes are as follows:

a) Some terms and definitions have been changed (see Chapter 3, Chapter 3 of the:2014 edition);

b) The detection principle has been changed (see 4.1, Chapter 4 of the:2014 edition);

c) Added ultrasonic guided wave testing technology classification (see 4.2);

d) The advantages, characteristics and limitations of ultrasonic guided wave testing have been deleted (see Chapter 4 of the:2014 edition);

e) The safety requirements have been changed (see Chapter 5, Chapter 5 of the:2014 edition);

f) The general testing process specifications have been changed (see Chapter 7, 7:1 of the:2014 edition);

g) The detection instrument system has been changed (see 8.1, 8:1 of the:2014 edition);

h) The ultrasonic guided wave sensor has been changed (see 8.2, 8:3 of the:2014 edition);

i) Added the detector function classification (see 8.3:1);

j) The test specimen has been changed (see 8.4, 8:7 of the:2014 edition);

k) The maintenance and verification of testing equipment has been modified (see 8.5, 8:8 of the:2014 edition);

l) Deleted the determination of test conditions (see 9.1:4 of the:2014 edition);

m) Added the selection of guided wave detection mode and frequency (see 9.2);

n) The detection implementation has been changed (see 9.5, 9:4 of the:2014 edition);

o) Added contrast detection (see 9.6);

p) The handling of unacceptable signals has been changed (see 10.2:4, 10:2:4 of the:2014 edition):

Introduction

As an important part of non-destructive testing, ultrasonic guided wave testing technology is widely used in petroleum, chemical industry, electric power, marine engineering, transportation, etc:

Detection of internal and external defects in waveguide structures such as pipelines, rails, plates and shells in the field, and detection in inaccessible areas such as covered layers and hidden shielding it has outstanding advantages, and has a long single detection distance and high work efficiency, providing an important technical means to ensure the safe operation of equipment:

Ultrasonic guided wave detection technology includes magnetostriction, piezoelectric ultrasound, electromagnetic ultrasound, laser ultrasound and other methods:

GB/T 31211 is intended to consist of two parts:

--- Part 1: General: The purpose is to specify the ultrasonic guided wave to tubes, bars, plates, wires, profiles and other cross-sectional geometry specifications the overall requirements for testing structural parts:

--- Part 2: Magnetostrictive method: The purpose is to specify the magnetostrictive ultrasonic method for quickly finding the cross-sectional loss in the component:

Specific requirements for wave detection:

This document is part 1 of GB/T 31211 and specifies the general requirements for ultrasonic guided wave testing:

In:2014, the GB/T 31211 ultrasonic guided wave testing standard system was established, which clarified the general technical requirements for ultrasonic guided wave testing and played a positive role in the development of ultrasonic guided wave testing:

The basic supporting role is conducive to promoting the popularization and application of ultrasonic guided wave detection technology:

Non-destructive testing Ultrasonic guided wave testing Part 1: General

1 Scope

This document describes the use of various ultrasonic guided waves such as magnetostrictive, piezoelectric ultrasonic, electromagnetic ultrasonic, laser ultrasonic, etc: to detect the components under test:

Use method:

This document is applicable to elastic solid structural parts with regular cross-sectional geometric shapes such as tubes, bars, plates, wires (including ropes and cables), profiles, etc:

Ultrasonic guided wave testing:

2 Normative references

The contents of the following documents constitute the 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 9445 Qualification and certification of non-destructive testing personnel GB/T 12604.1 Nondestructive testing terminology Ultrasonic testing GB/T 20737 General terms and definitions for non-destructive testing

3 Terms and definitions

The terms and definitions defined in GB/T 12604.1 and GB/T 20737 and the following apply to this document:

Waveguide

A structure that directs ultrasound waves of a specific frequency:

Note: For example, thin bars, tubes or thin plates: When the wall thickness is close to the wavelength, the longitudinal and transverse waves are affected by the boundary conditions and do not propagate in the original mode:

It is spread in a specific form:

Ultrasonic guided wave Ultrasonic waves propagating along the surface or inside of a waveguide (3:1) structure in a specific waveguide mode (3:6):

Dispersion

The phenomenon that wave speed changes with frequency:

Dispersive equation

The relationship between wave velocity and frequency is reflected by the equations that satisfy the special solutions of elastic dynamics according to specific boundary conditions:

Dispersion curve the curve of the relationship between wave velocity and frequency obtained by solving the dispersion equation (3:4):

Note: The abscissa of the dispersion curve represents the frequency-thickness product, frequency, wavelength or wave number, and the ordinate represents the group velocity or phase velocity: