Investigation of Non-Destructive Testing in Inner Cavity with Ant-Nest Structure Based on Positron Annihilation

2017 ◽  
Vol 373 ◽  
pp. 61-64 ◽  
Author(s):  
Jian Tang Liu ◽  
Min Zhao ◽  
Hui Xiao ◽  
Min Yao
Keyword(s):  
Positron Annihilation ◽  
Likelihood Estimation ◽  
Image Sequence ◽  
Nest Structure ◽  
Estimation Model ◽  
Destructive Testing ◽  
External Temperature ◽  
Testing Method ◽  
Ant Nest ◽  
Slice Image

The existing testing method could not accurately detect the defects in inner cavity with ant-nest structure in a part. The reasons are as follows: the shape of inner cavity is irregular, the distribution of wall thickness is uneven and the material composition is complex etc. A new testing method is proposed based on positron annihilation in this paper. The radionuclide solution is injected in inner cavity of the part and then produces positrons which would annihilate within 2 nanoseconds in the polylactide (PLA) material. The information of inner cavity is reflected by counting the γ photons produced by positron annihilation. The maximum likelihood estimation model (MLEM) with average compensation is established according to the detected γ photons. A 2D slice image sequence is obtained by order subset expectation maximization (OSEM) algorithm which solves the MLEM. The targets such as defects in the 2D slice image need to be enhanced by OTSU algorithm. A 3D image is reconstructed by the enhanced 2D slice image sequence which is used to the detection and location of the defects in inner cavity. Two experiments under different environment are conducted which aim at different ant-nest structure parts. The parts are made of different material and made by different manufacture process. A good testing result of the parts with complex shaped inner cavity could be obtained. The results would not change with the change of external temperature or magnetic field and the testing precision can reach to millimeter level.

Application of Gradient Based IR Thermography to the GRP Structures Inspection

2011 ◽  
Vol 488-489 ◽  
pp. 682-685 ◽  
Author(s):  
Lovre Krstulović-Opara ◽  
Endri Garafulić ◽  
Branko Klarin ◽  
Željko Domazet
Keyword(s):  
Pulse Heating ◽  
Non Destructive Testing ◽  
Ir Thermography ◽  
Destructive Testing ◽  
Heat Flows ◽  
Testing Method ◽  
Reinforced Polymer ◽  
Gradient Based ◽  
Non Destructive ◽  
Gradient Approach

The article presents application of non destructive testing method based on the pulse heating infrared thermography used to detect material anomalies for the case of glass reinforced polymer structures. The goal of presented research, based on the thermal gradient approach, is to establish the procedure capable of filtering out anomalies from other thermal influences caused by thermal reflections of surrounding objects, geometry influences and heat flows for observed object.

A New Non-destructive Testing Method Applied to Clinching

2021 ◽  
pp. 1461-1468
Author(s):  
Rémi Lafarge ◽  
Alexander Wolf ◽  
Christina Guilleaume ◽  
Alexander Brosius
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Testing Method ◽  
Non Destructive

A Non-Destructive Testing Method and Analysis for Air Pressure Distribution in the Stacks of Building Drainage Systems

2008 ◽  
Author(s):  
Cheng-Li Cheng ◽  
Wan-Ju Liao ◽  
Kuen-Chi He ◽  
Chia-Ju Yen
Keyword(s):  
Pressure Fluctuation ◽  
Drainage System ◽  
Field Testing ◽  
Air Pressure ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Drainage Systems ◽  
Existing Building ◽  
Testing Method ◽  
Non Destructive

A drainage system is one of the most essential facilities in building service engineering. Unfortunately relevant technology used today to analyze it was developed decades ago. This research investigated the case of existing building drainage systems in Taiwan, including our previous studies. The purpose of this paper is the development of a non-destructive testing method of air pressure fluctuation in a stacked building drainage system using field observation and experimental study of stack fluid mechanisms. A portable testing device is developed to execute field testing in existing drainage systems to determine air pressure fluctuation in the stacks of buildings. Meanwhile, the Fourier Transform Process is adopted in this paper to analyze the power spectrum of air pressure fluctuation in a drainage stack and to verify the previous theoretical study. Validation obtained from case-studies can be used to confirm the practicality of this portable and non-destructive testing method. As a result, the proposed testing method can be applied to the diagnosis of existing building drainage systems and improve the design of a drainage system in an existing housing complex.

ABOUT THE PROCEDURAL FRAMEWORK OF THE DIGITAL RADIOGRAPHY AT HAZARDOUS INDUSTRIAL FACILITIES

2019 ◽  
pp. 52-54
Author(s):  
K. A. Bagaev ◽  
N. N. Konovalov
Keyword(s):  
Digital Radiography ◽  
Modern Method ◽  
Necessary Condition ◽  
Imaging Plate ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Industrial Facilities ◽  
Testing Method ◽  
Radiation Testing ◽  
Non Destructive

Radiation testing is non-destructive testing method widely used to detect internal imperfections of technical devices, buildings and constructions at hazardous industrial facilities. Digital radiography is the modern method, which uses phosphor imaging plate as the detector of ionizing radiation. Creation of the relevant procedural framework is the necessary condition for the use of digital radiography at hazardous industrial facilities.

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