GB/T 34370.11-2020 in English

《GB/T 34370.11-2020游乐设施无损检测 第11部分：超声导波检测》由TC250（全国索道与游乐设施标准化技术委员会）归口，主管部门为国家标准化管理委员会。

Nondestructive testing of amusement equipments
Part 11: Ultrasonic guided wave testing

1 Scope

This part of GB/T 34370 specifies the method of ultrasonic guided wave testing and result evaluation for amusement equipments.

This part is applicable to ultrasonic guided wave testing and result evaluation for members of amusement equipments such as metal plates (including channel steel and square beams) with wall thickness of 4 mm~80 mm, steel pipes with diameter of 16 mm ~ 2000 mm and wall thickness of 2 mm~80 mm, steel ropes and cables with diameter of 12 mm~185 mm, tie rods with diameter of 16 mm~80 mm, etc.

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 (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

For the purposes of this document, the terms and definitions given in GB/T 12604.4, GB/T 20306, GB/T 20737, GB/T 28704 and GB/T 31211 apply.

4 Method summary

4.1 Principle of ultrasonic guided wave testing

According to characteristics of the member under testing, ultrasonic guided waves propagating along the member are excited in a certain way. When the guided wave encounters a flaw, it will produce a reflection echo. The echo signal is received by a receiving sensor, and the location and size of the flaw can be discriminated by analyzing the characteristics and propagation time of the echo signal.

Magnetostrictive ultrasonic guided wave testing method is a method of testing members by using ultrasonic guided waves produced by magnetostrictive effect.

Piezoelectric ultrasonic guided wave testing method is a method of testing members by using ultrasonic guided waves produced by piezoelectric effect.

4.2 Ultrasonic guided wave testing method for plates

SH wave or Lamb wave is generally used for ultrasonic guided wave testing of plates. Ultrasonic guided wave in SH mode is generally excited by sheet magnetostrictive transducer, while Lamb wave is generally excited by piezoelectric ultrasonic guided wave transducer. The principle of piezoelectric ultrasonic guided wave testing for plates is shown in Figure 1, while that of magnetostrictive ultrasonic guided wave testing for plates is shown in Figure 2. Ultrasonic guided wave testing method for plates may be used as that for members such as I-steel, channel steel, square beam, etc.
 




Figure 1 Principle of piezoelectric ultrasonic guided wave testing for plates



Figure 2 Principle of magnetostrictive ultrasonic guided wave testing

4.3 Ultrasonic guided wave testing method for pipes

Workpieces under testing, e.g., pipes, which are mainly characterized by a hollow cylindrical structure with a diameter greater than 20 mm are generally tested using magnetostrictive ultrasonic guided waves (indirect method) or piezoelectric ultrasonic guided waves. Magnetostrictive ultrasonic guided waves are generally used to test the pipes in torsional shear mode, while piezoelectric ultrasonic guided waves are generally used to test the pipes in longitudinal wave mode.

Magnetostrictive ultrasonic guided waves generate mechanical vibration on the magnetostrictive film based on magnetostrictive effect, and the vibration is transmitted from the magnetostrictive film to the member under testing in dry or gel coupling mode to form guided waves, thus realizing guided wave excitation. Guided waves are transmitted from the member under testing back to the magnetostrictive film in the same coupling mode, and guided waves are received based on the inverse magnetostrictive effect. This method is applicable to the testing of ferromagnetic materials and non-ferromagnetic materials, with the principle of testing shown in Figure 3. The ultrasonic guided wave sensor for this method includes coil and magnetostrictive film, and the latter needs to be pre-magnetized prior to use.



Figure 3 Principle of magnetostrictive ultrasonic guided wave testing for pipes

Piezoelectric ultrasonic guided waves generate mechanical vibration on piezoelectric materials based on inverse piezoelectric effect, and the vibration is transmitted from the piezoelectric chip to the member under testing in dry or gel coupling mode to form guided waves, thus realizing guided wave excitation. Guided waves are transmitted from the member under testing back to the piezoelectric chip in the same coupling mode, and guided waves are received based on the direct piezoelectric effect. This method is applicable to the testing of ferromagnetic materials and non-ferromagnetic materials, with the principle of testing shown in Figure 4. Piezoelectric ultrasonic guided wave tester for pipes usually consists of arrayed piezoelectric probes uniformly distributed around the circumference.



Figure 4 Principle of piezoelectric ultrasonic guided wave testing for pipes

4.4 Ultrasonic guided wave testing method for rods, cables and ropes

Rod, cable and rope members are mainly characterized by small-diameter solid steel members, with very small curvature of cross-section profile. Generally, ultrasonic guided wave transducers are difficult to be installed on the outer surfaces of the generally very large workpieces under testing in length.

Rod, cable and rope members should be tested by magnetostrictive ultrasonic guided wave testing method (direct method) to excite the guided wave in longitudinal mode. This method directly excites and receives guided waves in the member using the magnetostrictive effect of the material itself, and is only applicable to the testing of ferromagnetic materials, with the principle of testing shown in Figure 5. The sensor for this method consists of exciting coil, testing coil and magnetizer. The magnetizer is used to provide bias magnetic field with magnetostriction effect, and can be loaded in electromagnetic or permanent magnetic mode. The testing method should be pulse echo testing with separate reception and transmission.



Figure 5 Principle of ultrasonic guided wave testing for rods, cables and ropes

5 Safety requirements

This clause does not list all safety requirements for testing, so users of this standard shall establish safety guidelines prior to testing.

Safety requirements in the testing process shall at least include:

a) Before the testing, various hazards that may harm the testing personnel during the testing shall be identified, training shall be conducted for the testing personnel and necessary protective measures shall be taken;

b) The testing personnel shall comply with the safety requirements for the site of the member under testing, wear protective overalls and relevant protective equipment;

c) Attention shall be paid to avoid various potential safety hazards, such as bumping, electric shock, falling, squeezing, shearing, winding, slipping, drowning, scalding, etc.

d) During operation at heights, factors such as falling of personnel and testing apparatus shall be considered, and necessary protective measures shall be taken;

e) For testing in the running state of amusement equipments, targeted safety measures shall be established.

6 Personnel requirements

Personnel engaged in ultrasonic guided wave testing of amusement equipments shall comply with the relevant provisions of GB/T 34370.1.

Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Method summary
5 Safety requirements
6 Personnel requirements
7 Testing apparatus
8 Testing procedure specification
9 Testing procedure
10 Grading and treatment of testing results
11 Testing record and report