GB/T 34370.11-2020 PDF English
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Nondestructive testing of amusement equipments - Part 11: Ultrasonic guided wave testing
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GB/T 34370.11-2020: PDF in English (GBT 34370.11-2020) GB/T 34370.11-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 97.200.40
Y 57
Nondestructive testing of amusement equipments -
Part 11: Ultrasonic guided wave testing
ISSUED ON: NOVEMBER 19, 2020
IMPLEMENTED ON: JUNE 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 5
4 Method summary ... 5
5 Safety requirements ... 8
6 Personnel requirements ... 8
7 Testing equipment and instruments ... 9
8 Testing process specifications ... 16
9 Testing procedures ... 18
10 Classification and processing of test results... 22
11 Test record and report ... 23
Nondestructive testing of amusement equipments -
Part 11: Ultrasonic guided wave testing
1 Scope
This part of GB/T 34370 specifies the ultrasonic guided wave testing and result
evaluation methods for amusement equipment.
This Part is applicable to the ultrasonic guided wave testing and result evaluation of
amusement equipment components such as metal plates (including groove steels and
square beams) with a wall thickness of 4 mm ~ 80 mm, steel pipes with a diameter of
16 mm ~ 2000 mm and a wall thickness of 2 mm ~ 80 mm, steel wire ropes and cables
with a diameter of 12 mm ~ 185 mm, and pull rods with a diameter of 16 mm ~ 80 mm.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 12604.4, Non-destructive testing - Terminology - Terms used in acoustic
emission testing
GB/T 20306, Amusement devices terminology
GB/T 20737, Non-destructive testing - General terms and definitions
GB/T 28704, Non-destructive testing - Test method for ultrasonic guided wave
testing based on magnetostrictive effects
GB/T 31211, Non-destructive testing - Ultrasonic guided wave testing - General
principle
GB/T 34370.1, Nondestructive testing of amusement equipments - Part 1: General
requirement
GB/T 34370.3, Nondestructive testing of amusement equipments - Part 3:
Magnetic particle testing
GB/T 34370.4, Nondestructive testing of amusement equipments - Part 4:
Penetrant testing
GB/T 34370.5, Nondestructive testing of amusement equipments - Part 5:
Ultrasonic testing
GB/T 34370.6, Nondestructive testing of amusement equipments - Part 6:
Radiographic testing
GB/T 34370.7, Nondestructive testing of amusement equipments - Part 7: Eddy
current testing
GB/T 34370.9, Nondestructive testing of amusement equipments - Part 9:
Magnetic flux leakage testing
GB/T 34370.10, Nondestructive testing of amusement equipments - Part 10:
Magnetic memory testing
3 Terms and definitions
Terms and definitions determined by GB/T 12604.4, GB/T 20306, GB/T 20737, GB/T
28704 and GB/T 31211 are applicable to this document.
4 Method summary
4.1 Ultrasonic guided wave testing principle
According to the characteristics of the tested component, use a certain method to excite
ultrasonic guided waves that propagate along the component. When the guided wave
encounters a defect, it generates a reflected echo. Receive the echo signal by a receiving
sensor. By analyzing the echo signal characteristics and propagation time, the defect
location and size can be determined.
Test method for ultrasonic guided wave testing based on magnetostrictive effects is a
method of testing components by using the ultrasonic guided waves generated in the
components by magnetostrictive effects.
Test method for piezoelectric ultrasonic guided wave testing is a method of testing
components by using ultrasonic guided waves generated in the components by
piezoelectric effects.
4.2 Ultrasonic guided wave testing method for plates
Ultrasonic guided wave testing of plates is generally performed using SH waves or
Lamb waves. Ultrasonic guided waves in SH mode are generally excited by thin-film
magnetostrictive transducers, and Lamb waves are generally excited by piezoelectric
ultrasonic guided wave transducers. The testing principle of piezoelectric ultrasonic
guided waves for plates is shown in Figure 1, and the testing principle of
magnetostrictive ultrasonic guided waves for plates is shown in Figure 2. The ultrasonic
testing method should be A-scan or B-scan; if necessary, a combination of the
above methods can be used for testing;
d) For pipe fittings with a nominal diameter greater than DN800, the T (n,1) mode
should be used and the ultrasonic guided wave B-scan testing method should be
used.
7.2.3.3 Rod, cable and rope components to be tested
In the low-frequency region, the bending mode guided wave dispersion is serious and
is not suitable as a testing mode; the longitudinal mode and torsional mode dispersion
are small and are suitable as testing modes.
The torsional mode is not suitable as the testing mode of this type of component. The
axial vibration displacement of the longitudinal mode guided wave is much larger than
the radial vibration displacement, and is evenly distributed in the cross section of the
component, so it is suitable as a testing mode.
For rods, cables, ropes and other tested components that cannot be equipped with
transducers on the end faces, magnetostrictive transducers (direct method) should be
used for guided wave testing. For metal rope-type multi-filament components with a
diameter of more than 12 mm and a length of 1 000 m ~ 2 000 m, such components are
often used as support and traction structures. The two end faces of the components are
generally inaccessible, and the anchoring areas at both ends can be focused on; the
middle area can be tested by multiple moving segmented testing methods. For pull rods
with a diameter greater than 16 mm and a length greater than 10 m, the transducer
arrangement scheme is the same as that of rope components, and the longitudinal mode
should be selected for testing.
For tested components with a length of less than 1 m, such as rods, shafts, pins, bolts,
anchor bolts, etc., whose end faces can be installed with transducers, a piezoelectric
transducer should be used first to excite the end face of the tested component, and the
testing mode is generally the longitudinal wave mode.
7.3 Ultrasonic guided wave sensor
7.3.1 Classification of sensors
According to different contact methods, working principles of generating ultrasonic
waves, guided wave modes of exciting and receiving sensors, and detection methods,
sensors are classified as follows:
a) According to the contact mode between the sensor and the tested component, it
can be divided into dry coupling sensor, bonding sensor and non-contact sensor,
among which dry coupling sensor and bonding sensor are collectively referred
to as contact sensor;
b) According to the working principle of the sensor generating ultrasonic waves, it
can be divided into piezoelectric, magnetostrictive, electromagnetic ultrasonic
and laser ultrasonic;
c) According to the guided wave modes of sensor excitation and reception, it can
be divided into longitudinal guided wave sensors, torsional guided wave sensors,
bending guided wave sensors, and composite guided wave sensors;
d) According to the testing method, it can be divided into A-scan sensor and B-scan
sensor.
7.3.2 Selection of sensors
Since different sensors have different testing accuracy for different modes of guided
waves and defects, the following factors shall be considered when selecting sensors:
a) material properties of the components, such as whether they are conductive or
magnetic;
b) geometric shape of the components, such as pipes, bars, wires, profiles, plates,
etc.;
c) external conditions of the components, such as surface accessibility, coating
materials, etc.;
d) working environment conditions of the components, such as working
temperature, working medium and load-bearing conditions;
e) test purpose and type of defects to be tested, etc.
7.3.3 Installation of sensors
Depending on the type of sensors, the following factors shall be considered during
installation:
a) For contact sensors, the surface of the component to be tested shall be clean and
flat to improve coupling efficiency;
b) For piezoelectric sensors, their installation can refer to the requirements for
sensors in conventional ultrasonic testing;
c) For non-contact sensors, they shall be as close to the component being tested as
possible to reduce external interference such as electromagnetic interference and
vibration.
7.4 Excitation unit
The function of the excitation unit is mainly to generate the corresponding excitation
signal, and then drive the excitation sensor to excite the corresponding mode of guided
section loss rate respectively; the circumferential spacing of the flat-bottom
holes shall be evenly distributed, the longitudinal spacing distance shall be
greater than 1 m, and the depth tolerance shall not be greater than ±0.2 mm; the
flat-bottom holes at both ends of the test piece shall be at least 1 m away from
the end of the test piece.
c) For components such as wire cables, wire ropes or pull rods tied in wire form,
respectively machine fractures of the wire material at four locations on the
comparative test piece; the number of broken wires at each location shall be
calculated according to 2%, 4%, 8% and 10% of the cross-sectional loss rate
respectively, and the broken wires at the same location shall be closely adjacent;
the fractures at both ends of the test piece shall be at least 1 m away from the
end of the test piece; the spacing between fractures at different locations shall
be greater than 1 m, and they shall be evenly distributed in the circumferential
direction.
7.8 Maintenance and calibration of testing equipment
Written procedures shall be established for periodic maintenance and inspection of
testing equipment to ensure instrument functionality.
Before conducting on-site testing, test pieces for calibration of corresponding
specifications shall be selected in the laboratory to calibrate the testing instrument. If
the test results are consistent with the known defect distribution of the test pieces, it
indicates that the instrument is normal.
When conducting on-site testing, if there is any doubt about the equipment's test results,
the equipment shall be functionally checked and adjusted, and the results of each
maintenance inspection shall be recorded.
8 Testing process specifications
8.1 General testing process specifications
Units engaged in ultrasonic guided wave testing of amusement equipment shall
formulate general testing procedures in accordance with the requirements of GB/T
34370.1 and this Part, and the contents shall at least include the following elements:
a) a reference to this document;
b) scope of application;
c) reference standards and regulations;
d) qualifications of testing personnel;
e) testing instruments and equipment: sensors, sensor fixtures, signal lines,
preamplifiers, cables, instrument hosts, testing data acquisition and analysis
software, etc.;
f) information of the tested component: geometric shape and size, material, design
and operating parameters;
g) determination of testing coverage and sensor model;
h) surface condition of the test piece and installation method of the sensor;
i) timing of testing;
j) comparative test pieces and drawing of distance-amplitude curve;
k) testing process and data analysis and interpretation;
l) evaluation of test results;
m) archiving of test records, reports and information;
n) personnel responsible for the preparation, review and approval of process
specifications;
o) date of preparation.
8.2 Testing process card
For ultrasonic guided wave testing of each type of component, an ultrasonic guided
wave process card shall be formulated based on actual conditions, in accordance with
GB/T 34370.1, this Part and the general testing procedures.
The content of the test process card shall at least include:
a) process card number;
b) standards for testing implementation;
c) information on the tested components, including: equipment name, number,
material and geometric dimensions, etc.;
d) testing instruments and equipment: name, specification, model, number, etc.;
e) testing method and sensor model;
f) timing of testing;
g) surface condition of the test piece and installation method of the sensor;
h) testing schematic diagram;
9.3 Installation of sensor
The installation of the sensor shall meet the following requirements:
a) Determine the specific location of the sensor installation on the tested object
according to the determined testing plan. The installation location of the sensor
shall be as far away as possible from the complex structural parts such as the
connection and support of the tested object;
b) Carry out surface treatment on the installation part of the sensor to make it meet
the installation requirements of the sensor;
c) Press the sensor onto the surface of the test piece to achieve good acoustic
coupling between the sensor and the surface of the test piece;
d) Use mechanical clamps, magnetic clamps or other means to firmly fix the sensor
on the test piece, and keep the sensor insulated from the test piece and the fixing
device.
9.4 Testing
9.4.1 Testing equipment debugging
The debugging of the testing equipment includes the following steps:
a) Connect the sensor, preamplifier and instrument host;
b) Turn on the instrument and preheat it for the time specified by the manufacturer
to allow the instrument to reach a stable working state;
c) Set the instrument’s operating parameters according to the specific conditions of
the test piece and the test frequency determined by the dispersion curve
calculation;
d) Transmit ultrasonic guided wave signals to the tested component, observe the
ultrasonic guided wave reflection signals generated by the ends, joints, welds,
external supports and other parts of the component, and measure the wave
velocity of ultrasonic guided wave propagation of the tested component;
e) Further adjust the instrument operating parameters to keep the instrument in
good working condition.
9.4.2 Analysis and interpretation of A-scan testing signals
The analysis and interpretation of testing signals usually requires reference to the
database established by relevant experiments, which shall at least include the following:
a) Use the adjusted instrument to test the component to be tested, and observe and
record the ultrasonic guided wave reflection echo signal;
b) For the ultrasonic guided wave reflected echo signals that appear, first determine
whether these signals are generated by the ends, joints, welds, external supports,
etc. of the component. If so, they can be eliminated;
c) For ultrasonic guided wave echo signals at locations without obvious geometric
shape changes on the test piece, which can be determined as ultrasonic guided
wave echo signals caused by material loss defects, first determine the reflection
location of this echo signal and mark it; then, evaluate and process the test results.
9.4.3 Analysis and interpretation of B-scan imaging testing signals
Compared with A-scan testing, B-scan testing has an additional position information
perpendicular to the propagation direction of the guided wave. The analysis and
interpretation of its testing signal includes at least the following contents:
a) Use the adjusted instrument and B-scan sensor to perform B-scan testing on the
component to be tested, observe and record the ultrasonic guided wave
reflection echo signal and draw the B-scan image;
b) For the drawn B-scan image signals, combined with the added position
information, firstly perform a qualitative analysis of the characteristics, and then
determine whether these signals are generated by the ends, joints, welds,
external supports, etc. of the component. If confirmed, they can be excluded;
c) For ultrasonic guided wave echo signals at locations without obvious geometric
shape changes on the test piece, it can be determined that they are ultrasonic
guided wave echo signals caused by material loss defects. For multiple reflected
echo color blocks at the same sound path position, the number of suspected
defects at the position can be determined first, and marked, and then the test
results can be evaluated and processed.
Table 2 lists the qualitative analysis of some pipe fittings characteristics when the pipe
fittings are tested using B-scan.
Figure 10 is a guided wave testing imaging diagram of a pipe fitting when it is tested
by B-scan. In the diagram, the weld characteristics and defect characteristics on the pipe
fitting can be analyzed through the circumferential information of the pipe fitting
characteristics, and two defects in the same axial direction can be distinguished.
Table 2 – Qualitative analysis of B-scan testing characteristics in pipe fittings
Category B-scan imaging characteristics Typical characteristic structure
Circumferential
characteristics
At the same axial distance, all
circumferential positions of the pipe have
echoes
Welds, flanges, etc.
Generally, signals judged as Grade III, Grade IV and Grade V in the test results are
unreceivable signals.
10.2.3 Determination based on real defects on the tested component
First, the first three largest defect signal locations found during the testing can be re-
tested according to the method specified in 10.2.4, and the grade of unreceivable defect
signals can be gradually determined based on the re-testing results.
10.2.4 Handling of unreceivable signals
For confirmed unreceivable signals, the following methods need to be used for re-
testing:
a) First, use visual inspection and hammer tapping to distinguish whether the
defects are located on the outer surface or inside;
b) For external surface defects, use a depth gauge to directly measure the depth of
the defect;
c) For inner surface defects of tubular or plate shape, ultrasonic testing and
measurement shall be carried out using a dual crystal straight probe to more
accurately measure the depth of the defects. The ultrasonic testing method shall
be implemented in accordance with GB/T 34370.5;
d) For inner surface defects of components of other shapes, select appropriate non-
destructive testing methods for re-testing in accordance with the provisions of
GB/T 34370.3 ~ GB/T 34370.7 and GB/T 34370.9 ~ GB/T 34370.10;
e) If necessary, with the user's consent, verification may also be carried out by
autopsy sampling.
11 Test record and report
11.1 Test record
The main contents of the test record shall not be less than those specified in 8.2 and
11.2.
11.2 Test report
The test report shall at least include the following:
a) information of the client;
b) information of the testing unit;
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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