A Bayesian Approach for Effective Use of Multiple Measurements of Crack Depths

2020 ◽  
Author(s):  
Smitha D. Koduru ◽  
Maher Nessim ◽  
Steven Bott ◽  
Mohammad Al-Amin
Keyword(s):  
Depth Distribution ◽  
Crack Depth ◽  
Field Measurements ◽  
Crack Size ◽  
Multiple Measurements ◽  
Error Bias ◽  
Effective Use ◽  
Non Destructive ◽  
Size Estimates

Abstract A Bayesian methodology was applied to use data from multiple inline inspection (ILI) runs and field measurements with non-destructive examination (NDE) tools to increase confidence in crack size estimates. Multiple crack depth measurements were used in two different ways — namely, to improve the characterization of ILI sizing error bias and to update the maximum depth distribution of individual crack features. This methodology was applied to selected datasets from an industrywide database for crack ILI data collected over a series of Pipeline Research Council International (PRCI) projects. The results of the approach are presented for two datasets, showing reduced variance in sizing error bias and improved confidence in crack depth estimates. In addition to the PRCI datasets, an additional dataset was collected and used to investigate the effect of multiple ILI runs on estimates of rate of detection and depth distribution of undetected features. The results of this analysis are also summarized.

Characterization of Surface Crack Using Surface Waves

2012 ◽  
Vol 166-169 ◽  
pp. 1931-1934
Author(s):  
Shiuh Chuan Her ◽  
Sheng Tung Lin
Keyword(s):  
Surface Waves ◽  
Surface Crack ◽  
Crack Depth ◽  
Test Results ◽  
Ultrasonic Technology ◽  
Different Depths ◽  
Incident Waves ◽  
Non Destructive ◽  
Depth Detection

Surface cracks are the most common defects in structures. Ultrasonic has been widely used as a non-destructive evaluation technology in the case of crack characterization. In this investigation, surface waves are applied to a steel block with artificial slots to characterize the crack depth. A series of test specimen with different depths of surface crack ranging from 4mm to 10mm was fabricated. The depth of the surface crack was evaluated using the pitch-catch ultrasonic technology. In this work, 2.25 MHz, 5 MHz and 10 MHz of incident waves were employed to investigate the effect of frequency on the crack depth detection. Experimental test results show that the accuracy of crack depth detection is increasing with the increase of frequency.

Non-Destructive Characterization of Welding Defects Using MMM and ACFM Methods

2014 ◽  
Vol 881-883 ◽  
pp. 1773-1777
Author(s):  
Ya Tian Gao ◽  
Li Hua Wang ◽  
Xiu Jie Miao ◽  
Jian Cheng Leng
Keyword(s):  
Detection Efficiency ◽  
Crack Depth ◽  
Magnetic Memory ◽  
Current Field ◽  
Tubular Specimen ◽  
Early Stress ◽  
Welding Defects ◽  
Non Destructive ◽  
Non Destructive Characterization

Nondestructive inspection and evaluation of welds is very important to ensure the safety of industrial products. In this study, the metal magnetic memory (MMM) and alternating current field measurement (ACFM) methods are utilized to characterize welding defects of a butt welded tubular specimen respectively. The results show that the MMM method has potentials in evaluating both early stress concentration and macro-defects but only qualitatively, while the ACFM method can provide crack depth sizing information quantitatively, suggesting that the two methods should be combined for nondestructive evaluation welding defects to improve the detection efficiency and accuracy.

Applications of SIMS to electronic materials and devices

1992 ◽  
Vol 50 (2) ◽  
pp. 1682-1683
Author(s):  
S.F. Corcoran
Keyword(s):  
Depth Distribution ◽  
Secondary Ion Mass Spectrometry ◽  
Semiconductor Device ◽  
Electronic Materials ◽  
Profile Analysis ◽  
Semiconductor Industry ◽  
Small Diameter ◽  
Depth Resolution ◽  
Detection Sensitivity

Over the past decade secondary ion mass spectrometry (SIMS) has played an increasingly important role in the characterization of electronic materials and devices. The ability of SIMS to provide part per million detection sensitivity for most elements while maintaining excellent depth resolution has made this technique indispensable in the semiconductor industry. Today SIMS is used extensively in the characterization of dopant profiles, thin film analysis, and trace analysis in bulk materials. The SIMS technique also lends itself to 2-D and 3-D imaging via either the use of stigmatic ion optics or small diameter primary beams.By far the most common application of SIMS is the determination of the depth distribution of dopants (B, As, P) intentionally introduced into semiconductor materials via ion implantation or epitaxial growth. Such measurements are critical since the dopant concentration and depth distribution can seriously affect the performance of a semiconductor device. In a typical depth profile analysis, keV ion sputtering is used to remove successive layers the sample.

scholarly journals Terahertz characterization of two-dimensional low-conductive layers enabled by metal gratings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prashanth Gopalan ◽  
Yunshan Wang ◽  
Berardi Sensale-Rodriguez
Keyword(s):  
Optical Transmission ◽  
Terahertz Spectroscopy ◽  
Design Guidelines ◽  
Two Dimensional ◽  
Highly Sensitive ◽  
Transmission Measurements ◽  
Metal Gratings ◽  
Low Sensitivity ◽  
Non Destructive

AbstractWhile terahertz spectroscopy can provide valuable information regarding the charge transport properties in semiconductors, its application for the characterization of low-conductive two-dimensional layers, i.e., σs <  < 1 mS, remains elusive. This is primarily due to the low sensitivity of direct transmission measurements to such small sheet conductivity levels. In this work, we discuss harnessing the extraordinary optical transmission through gratings consisting of metallic stripes to characterize such low-conductive two-dimensional layers. We analyze the geometric tradeoffs in these structures and provide physical insights, ultimately leading to general design guidelines for experiments enabling non-contact, non-destructive, highly sensitive characterization of such layers.

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