An Improved Phased Array Ultrasonic Testing Technique for Thick-Wall Polyethylene Pipe Used in Nuclear Power Plant

2018 ◽  
Author(s):  
Yinkang Qin ◽  
Jianfeng Shi ◽  
Jinyang Zheng
Keyword(s):  
Numerical Simulation ◽  
Ultrasonic Testing ◽  
Nuclear Power ◽  
Phased Array ◽  
Propagation Distance ◽  
Ultrasonic Field ◽  
Thick Wall ◽  
Acoustic Attenuation ◽  
Waveform Distortion ◽  
Attenuation And Dispersion

With the application of High-density polyethylene (HDPE) pipe with thick wall in nuclear power plant (NPP), great attention has been paid to the safety of the pipeline’s joints, which can be assessed by phased array ultrasonic testing (PAUT). PAUT creates constructive interference of acoustic waves to generate focused beams according to delay law based on time-of-flight. However, due to the existence of acoustic attenuation and dispersion, waveform distortion occurs when ultrasonic pulse propagates in HDPE, which will accumulate with the increase of propagation distance, and then results in imaging errors. In this paper, the relationship of acoustic attenuation and dispersion in HDPE was obtained by numerical simulation in Field II®, which can be verified by the experiment of our previous work. Besides, the investigation of the waveform distortion revealed the linear relation between peak offset and propagation distance. Considering the relation, an improved delay law was proposed to increase the intensity of ultrasonic field. This improved delay law was compared with the conventional one by numerical simulation of ultrasonic field and PAUT experiments, which showed that the improved delay law could increase the image sensitivity.

An Improved Phased Array Ultrasonic Testing Technique for Thick-Wall Polyethylene Pipe Used in Nuclear Power Plant

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Yinkang Qin ◽  
Jianfeng Shi ◽  
Jinyang Zheng ◽  
Dongsheng Hou ◽  
Weican Guo
Keyword(s):  
Numerical Simulation ◽  
Ultrasonic Testing ◽  
Nuclear Power ◽  
Phased Array ◽  
Propagation Distance ◽  
Ultrasonic Field ◽  
Thick Wall ◽  
Acoustic Attenuation ◽  
Waveform Distortion ◽  
Attenuation And Dispersion

With the application of high-density polyethylene (HDPE) pipe with thick wall in nuclear power plant (NPP), great attention has been paid to the safety of the pipeline joints, which can be assessed by phased array ultrasonic testing (PAUT). PAUT creates constructive interference of acoustic waves to generate focused beams according to delay law based on time-of-flight. However, due to the existence of acoustic attenuation and dispersion, waveform distortion occurs when ultrasonic pulse propagates in HDPE, which will accumulate with the increase of propagation distance, and then results in imaging errors. In this paper, the relationship between acoustic attenuation and dispersion in HDPE was obtained by numerical simulation in Field II®, which can be verified by the experiment of our previous work. Then, the investigation of the waveform distortion revealed the linear relation between peak offset and propagation distance. Considering the relation, an improved delay law was proposed to increase the intensity of ultrasonic field. This improved delay law was compared with the conventional one by numerical simulation of ultrasonic field and PAUT experiments, which showed that the improved delay law could increase the image sensitivity.

Acoustic Field Simulation of an Antenna Array at Scanning by the SPA Method for Modern Ultrasonic Testing Technologies

2014 ◽  
Vol 1040 ◽  
pp. 959-964 ◽  
Author(s):  
Irina O. Bolotina ◽  
H. Michael Kroening ◽  
K.G. Kvasnikov ◽  
Dmitriy A. Sednev ◽  
Olga V. Sumtsova
Keyword(s):  
Numerical Simulation ◽  
Signal Processing ◽  
Antenna Array ◽  
Radiation Pattern ◽  
Ultrasonic Testing ◽  
Array Signal Processing ◽  
Phased Array ◽  
Main Lobe ◽  
Field Simulation ◽  
Acoustic Field Simulation

The results of numerical simulation of an antenna array radiation pattern in impulse mode by the method of sampling phased array signal processing are represented in this paper. The studies of array parameters impact (the number of elements and the distance between them) on its penetrometer characteristics are discussed. It is established that the change of the distance among array elements leads to narrowing of the main lobe of the radiation pattern as well as to shifting of the side lobes nearer to the main one. Meanwhile, the increase in the number of elements in the array leads to narrowing of the main lobe and decreasing of the side lobes level.

Using Phased Array Ultrasonic Testing in Lieu of Radiography for Acceptance of Carbon Steel Plate Welds

2014 ◽  
Author(s):  
Traci L. Moran ◽  
Michael T. Anderson ◽  
Anthony D. Cinson ◽  
Susan L. Crawford ◽  
Matthew S. Prowant ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Ultrasonic Testing ◽  
Nuclear Power ◽  
Phased Array ◽  
Steel Plate ◽  
National Laboratory ◽  
Pacific Northwest National Laboratory ◽  
Nuclear Regulatory Commission ◽  
Incomplete Fusion ◽  
Replacement Method

The Pacific Northwest National Laboratory (PNNL) is conducting studies for the U.S. Nuclear Regulatory Commission (NRC) to assess the capability, effectiveness, and reliability of ultrasonic testing (UT) as a replacement method for radiographic testing (RT) for volumetric examination of nuclear power plant (NPP) components. This particular study focused on evaluating the use of phased-array (PA) UT on carbon steel plate welds. Welding fabrication flaws included a combination of planar and volumetric types; for example, incomplete fusion, lack of penetration, cracks, porosity, and slag inclusions. The examinations were conducted using PAUT techniques applied primarily for detection and flaw type characterization. This paper will discuss the results of using PAUT in lieu of RT for detection and classification of fabrication flaws in carbon steel plate welds.

Phased Array Ultrasonic Inspection Technique for Cast Austenitic Stainless Steel Parts of Nuclear Power Plants

2016 ◽  
Author(s):  
Setsu Yamamoto ◽  
Jun Semboshi ◽  
Azusa Sugawara ◽  
Makoto Ochiai ◽  
Kentaro Tsuchihashi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultrasonic Testing ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Phased Array ◽  
Ultrasonic Inspection ◽  
Inspection Time ◽  
Accuracy Measurement

For safety operation of nuclear power plants, soundness assurance of structures has been strongly required. In order to evaluate properties of inner defects at plant structures quantitatively, non-destructive inspection using ultrasonic testing (UT) has performed an important role for plant maintenances. At nuclear power plants, there are many structures made of cast austenitic stainless steel (e.g. casings, valve gages, pipes and so on). However, UT has not achieved enough accuracy measurement at cast stainless steels due to the noise from large grains. In order to overcome the problem, we have developed comprehensively analyzable phased array ultrasonic testing (PAUT) system. We have been noticing that dependency of echo intensity from defect is different from grain noises when PAUT conditions (for example, ultrasonic incident angles and focal depths) were continuously changed. Analyzing the tendency of echoes from comprehensive PAUT conditions, defect echoes could be distinguished from the noises. Meanwhile, in order to minimize the inspection time on-site, we have developed the algorithms and the full matrix capture (FMC) data acquisition system. In this paper, the authors confirmed the detectability of the PAUT system applying cast austenitic stainless steel (316 stainless steel) specimens which have sand-blasted surface and 3 slits which made by electric discharge machining (EDM).

Investigation on Acoustic Propagation of Ultrasound in Polyethylene Pipe Used in Nuclear Power Plant

2017 ◽  
Author(s):  
Xiong Sheng ◽  
Dongsheng Hou ◽  
Jinyang Zheng
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Phase Velocity ◽  
Attenuation Coefficient ◽  
Nuclear Power ◽  
Image Resolution ◽  
Energy Concentration ◽  
Acoustic Attenuation ◽  
Hdpe Pipe ◽  
Attenuation And Dispersion

Polyethylene (PE) pipe, particularly high-density polyethylene (HDPE) pipe, has been successfully utilized to transport cooling water for both non-safety-related applications and safety-related applications in nuclear power plant (NPP). However, concerns of a lack of non-destructive examination (NDE) procedures and qualifications specialized for HDPE pipe impede its broader application. Traditional approximation without considering effects of acoustic dispersion could work for PE pipe with a small inspection depth. But for PE pipe of large size used in nuclear power plant, effects of acoustic attenuation and dispersion accumulate with depth, and have influence on waveforms of target pules, which brings great challenges to the energy concentration when performing ultrasonic phased-array inspection for PE pipe in NPP. In this paper, a theoretical method applying Szabo’s causal convolutional propagation operator based on causality theory was presented to obtain wave equations of ultrasound in PE considering both attenuation and dispersion, in which attenuation coefficient and phase velocity were used to separately characterize acoustic attenuation and dispersion. Then, an experimental method using ultrasonic spectroscopy technology was proposed to confirm the proposed model, and a good agreement was obtained. The results indicated that attenuation coefficient of PE had an approximately linear relation with frequency and that phase velocity rose logarithmically with frequency. Finally, effects of attenuation and dispersion on amplitude spectrum and waveform in time domain of the target signal were investigated. Frequency downshift and time delay shift had an influence on image resolution and focus capability, and were believed to be a restriction of current inspection technology. This work also theoretically proved that lower testing frequencies (less than 2.5MHz) could improve the inspection effectiveness of the applied inspecting systems for HDPE pipes in NPP applications.

Sign in / Sign up

Export Citation Format

Share Document