Qualification of a Combined Ultrasonic Inspection Tool for Detection and Sizing of Circumferential Weld Cracks in Offshore Pipelines

2014 ◽  
Author(s):  
Herbert Willems ◽  
Hans Petter Bjørgen ◽  
Thor-Ståle Kristiansen ◽  
Guus Wieme
Keyword(s):  
Fatigue Testing ◽  
Fatigue Cracks ◽  
Ultrasonic Inspection ◽  
Probability Of Detection ◽  
Offshore Pipelines ◽  
Fast Screening ◽  
Standard Application ◽  
Weld Area ◽  
Pulse Echo ◽  
Non Destructive

The target of inline crack inspection is normally related to the detection of axial cracks (weld cracks, SCC etc.) as axial cracks are usually expected under typical loading conditions in pressurized pipe. Ultrasonic crack inspection tools for this type of cracks have been available for over 20 years and have become a standard application in the ILI business. However, under certain conditions circumferential cracking may occur and the inspection technique needs to be modified accordingly. Especially under offshore conditions with limited pipeline accessibility not only the early detection of crack-like defects is required but also a precise depth sizing is important in order to minimize the risk of crack-related pipeline failure. In order to ensure a high probability of detection together with state-of-the-art depth sizing, a 10″ inline inspection tool was developed for the detection of circumferentially orientated weld cracks. The tool combines the advantages of the pulse-echo technique on the detection side with the excellent capabilities of the TOFD (time-of-flight-diffraction) technique for accurate sizing. Both techniques are implemented into a tethered tool where the pulse-echo unit serves for fast screening while the relatively slow TOFD-unit is used for sizing of any detected crack-like features. In order to qualify the new tool for a special offshore application (inspection of circumferential cracking at welded anode pads) extensive testing was performed using a 10″ test pipeline prepared by Statoil. The test line contained 64 artificial weld defects for reference purposes as well as an unknown number of fatigue cracks in the weld area which were generated by fatigue testing of the corresponding pipes. The tests were full blind tests with no advance knowledge on locations and sizes of the cracks. The sizes of the fatigue cracks (length, depth) were determined by destructive examinations carried out after inline testing. The subsequent comparison of the destructive results with the non-destructive results showed that the specification of the tool with regard to detection and sizing was fully met. In the paper, the inspection concept and the setup of the new tool are described, and the results of the qualification tests are presented.

THE FEATURES OF NON-DESTRUCTIVE INSPECTION OF CARBON FIBER REINFORCED PLASTIC SOLID LAMINATE SAMPLES DURING LOW-CYCLIC FATIGUE TESTING

2020 ◽  
pp. 108-115
Author(s):  
A.S. Boychuk ◽  
◽  
I.A. Dikov ◽  
A.S. Generalov ◽  
S.I. Yakovleva ◽  
...  
Keyword(s):  
Fatigue Testing ◽  
Ultrasonic Inspection ◽  
Cyclic Fatigue ◽  
Ultrasonic Pulse ◽  
Back Wall ◽  
Testing Specimen ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Pulse Echo ◽  
Non Destructive

The results of CFRP samples ultrasonic inspection during low-cyclic fatigue testing are given in this article. It is established that for ultrasonic pulse-echo inspection during cycling mechanical testing and after the special correction of flaw detector’s gain and inspection’s sensitivity concerning back-wall echo decreasing in compare with testing specimen is necessary.

scholarly journals A robot for non-destructive testing weld inspection of offshore mooring chains

2018 ◽  
Vol 15 (3) ◽  
pp. 172988141877053
Author(s):  
A Hernandez ◽  
O Altuzarra ◽  
V Petuya ◽  
Ch Pinto ◽  
E Amezua
Keyword(s):  
Visual Information ◽  
Ultrasonic Inspection ◽  
Flaw Detection ◽  
Destructive Testing ◽  
Usual Practice ◽  
Butt Welding ◽  
Steel Bar ◽  
Subsystem Design ◽  
Weld Area ◽  
Pulse Echo

Welding flaw detection is a key step in manufacturing many components. In offshore chains, every link is manufactured from a steel bar that is bent and the ends joined by flash butt welding. Ultrasonic inspection of the welded area is required for classification. Defects, if any, are parallel to the welded area, which do not favour detection by manual inspection with 45° beams, as per usual practice . This article reports on CIRUS, a robot developed for automatic inspection of the weld area using a combination of pulse-echo and pitch-catch ultrasonic testing. The robot kinematic structure includes global positioning, local positioning and inspection subsystems, and each subsystem design is described in detail. A data acquisition system processes ultrasonic inspection results and provides visual information for the inspector as well as traceability for quality manufacturing.

Detection and Monitoring of Fatigue Cracks in Metallic Structures Using Acoustic Emission: Routes to Quantification of Probability of Detection

2014 ◽  
Vol 891-892 ◽  
pp. 1268-1274 ◽  
Author(s):  
Daniel Gagar ◽  
Peter Foote ◽  
Phil E. Irving
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Cracks ◽  
Failure Process ◽  
Probability Of Detection ◽  
Metallic Structures ◽  
Final Failure ◽  
Ae Signal ◽  
Non Destructive ◽  
Ae Signals

The performance and reliability of Structural Health Monitoring (SHM) techniques remain largely unquantified. This is in contrast to the probability of detection (POD) and sensitivity of manual non destructive inspection methods which are well characterised. In this study factors influencing the rates of emission of Acoustic Emission (AE) signals from propagating fatigue cracks were investigated. Fatigue crack growth experiments were performed in 2014 T6 aluminium sheet to observe the effects of changes in crack length, loading spectrum and sample geometry on rates of emission and the probability of detecting and locating the fatigue crack. Significant variation was found in the rates of AE signal generation during crack progression from initiation to final failure. AE signals at any point in the failure process were found to result from different failure mechanisms operating at particular stages in the failure process.

Verification of the Ultrasonic Qualification for Structural Integrity of Partially Concrete Embedded Steel Elements

2009 ◽  
Vol 65 ◽  
pp. 69-78 ◽  
Author(s):  
J. Alfredo López ◽  
Francisco J. Carrión ◽  
Juan A. Quintana ◽  
Didier Samayoa-Ochoa ◽  
María G. Lomelí ◽  
...  
Keyword(s):  
Grain Size ◽  
Structural Integrity ◽  
Fatigue Cracks ◽  
Good Condition ◽  
Ultrasonic Inspection ◽  
Structural Elements ◽  
Ultrasonic Evaluation ◽  
Statistical Mechanical ◽  
Microstructural Integrity ◽  
Non Destructive

Failure of one upper anchorage element in a cable-stayed bridge and its consequent analysis concluded that the main cause of the failure was a deficient heat treatment that resulted in large micro structural grain size and low fracture toughness, vulnerable to fatigue damage. Previous research studies demonstrated that ultrasonic evaluation could provide some insight of the microstructural integrity by correlating the ultrasonic response to the grain size. Thus, this technique was used to inspect the 112 elements in service in the bridge and 16 were qualified as structurally deficient, without direct verification of the grain size, since these elements were partially embedded in the concrete structure. Late rehabilitation of the bridge considered the replacement of the 16 structural deficient anchorage elements, plus 4 elements qualified in good condition, to complete a reliability analysis for the remaining 92 elements from the statistical mechanical properties of the removed pieces. Rehabilitation made possible the confirmation of the initial diagnosis made by ultrasonic inspection and fatigue cracks were identified in some elements. This study demonstrated that the ultrasonic non destructive evaluation is highly reliable for structural integrity qualification of steel structural elements partially embedded in concrete.

scholarly journals Novel Damage Detection Techniques for Structural Health Monitoring Using a Hybrid Sensor

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Dengjiang Wang ◽  
Jingjing He ◽  
Banglin Dong ◽  
Xiaopeng Liu ◽  
Weifang Zhang
Keyword(s):  
Damage Detection ◽  
Fatigue Testing ◽  
Fatigue Cracks ◽  
Probability Of Detection ◽  
Model Parameters ◽  
The Novel ◽  
Plate Structures ◽  
Experimental Procedure ◽  
Detection Techniques ◽  
Sensor Monitoring

This study presents a technique for detecting fatigue cracks based on a hybrid sensor monitoring system consisting of a combination of intelligent coating monitoring (ICM) and piezoelectric transducer (PZT) sensors. An experimental procedure using this hybrid sensor system was designed to monitor the cracks generated by fatigue testing in plate structures. A probability of detection (POD) model that quantifies the reliability of damage detection for a specific sensor or the nondestructive testing (NDT) method was used to evaluate the weight factor for the ICM and PZT sensors. To estimate the uncertainty of model parameters in this study, the Bayesian method was employed. Realistic data from fatigue testing was used to validate the overall method, and the results show that the novel damage detection technique using a hybrid sensor can quantify fatigue cracks more accurately than results obtained by conventional sensor methods.

Non-Destructive Testing with Ultrasound in Rails and Ship Plates

2014 ◽  
Vol 605 ◽  
pp. 613-616
Author(s):  
Panagiotis I. Chatzifotis
Keyword(s):  
Ultrasonic Inspection ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Ultrasound Technique ◽  
Straight Beam ◽  
Pulse Echo ◽  
Thickness Measurements ◽  
Non Destructive ◽  
Pulse Echo Method

This paper deals with finding of defects, such as cracks, breakdowns and inclusions in rails and in ship plates, by ultrasound technique. Pulse echo method and twin beams technique is some of the ultrasonic inspection methods we have used for thickness measurements and for inspection of the welds. Initially, the thickness of rails and ship plates was measured by ultrasound devices using straight beam transducers and then the weldings of these samples were checked by using angle beam transducers.

Inspection of Fastener Holes Using Ultrasonic Phased Arrays

2001 ◽  
Author(s):  
Pamela G. Herzog ◽  
Vincent Lupien ◽  
James T. Miller ◽  
John J. Selman ◽  
Michael Moles
Keyword(s):  
Phased Array ◽  
Phased Arrays ◽  
Fatigue Cracks ◽  
Probability Of Detection ◽  
Skin Thickness ◽  
Inspection Method ◽  
Wide Range ◽  
Trade Study ◽  
Pulse Echo ◽  
Moving Parts

Abstract An Air Force Aging Aircraft Project was initiated to identify a suitable replacement for the Autoscan. The Autoscan is a unique piece of equipment that was originally identified for specific inspections for detection of first-layer, faying surface fatigue cracks (.030″ and larger) around fastener holes beneath the fastener heads, without removal of the fastener. The currently inspected parent material ranges from .125 to .3 inches thick, 2024T3 or 7075-T73 aluminum. Potential also exists for replacing other aging inspection equipment such as the Rotoscan. A secondary objective was to evaluate the feasibility of expanding the inspection capabilities to detect corrosion as well as cracks. A Trade Study was conducted initially to consider existing technologies available, trade-offs, and technology insertion in order to meet the required performance parameters. The trade study showed Phased Array Ultrasonics to have the greatest potential, so it was chosen as the inspection method to pursue. Using phased arrays, a novel inspection technique for rapidly and reliably inspecting the area around fastener holes for cracks and corrosion has been developed with no moving parts. Specially designed probes are used for the aircraft inspections. This design consists of a three-dimensional matrix of 504 ultrasonic elements on a cone that encircles the fastener head. The two-dimensional arrangement of elements permits deflection of the ultrasonic beam in three dimensions. Full circumferential scans are performed by programming the phased array focal laws to scan 360° of the fastener holes, using a combination of the following scan patterns: pulse-echo at 45° incident on the crack, pulse-echo at 90°, pitch-catch, plus local scanning. This capability allows flexible coverage of the fastener hole and surrounding area, again with no moving parts. Additionally, the beam deflection capability means that one probe is adaptable to a wide range of fastener diameters and skin thickness. Several conical sub-arrays were built to evaluate the feasibility of the concept experimentally. The experimental results along with numerical modeling were used to determine optimal values for inner and outer radii of the cone, angle of the cone, number of elements and arrangement of the elements. A complete prototype conical array was subsequently built. The final portion of this project includes developing the specific inspection procedures, and performing a Probability of Detection study (POD) developed by the FAA’s Airworthiness Assurance Nondestructive Tested Validation Center at Sandia National Laboratory.

scholarly journals Capability of Advanced Ultrasonic Inspection Technologies for Hydraulic Turbine Runners

2021 ◽  
Vol 11 (10) ◽  
pp. 4681
Author(s):  
Mohammad Ebrahim Bajgholi ◽  
Gilles Rousseau ◽  
Martin Viens ◽  
Denis Thibault
Keyword(s):  
Ultrasonic Inspection ◽  
High Stress ◽  
Welding Process ◽  
Hydraulic Turbine ◽  
Francis Turbine ◽  
Detection Rates ◽  
Critical Range ◽  
Area Of Interest ◽  
Ambitious Program ◽  
Pulse Echo

This paper presents the results of a project aimed at evaluating the performance of ultrasonic techniques for detecting flaws in Francis turbine runners. This work is the first phase of a more ambitious program aimed at improving the reliability of inspection of critical areas in turbine runners. Francis runners may be utilized to supply power during peak periods, which means that they experience additional load stress associated with start and stop sequences. Inspection during manufacturing is then of paramount importance to remove as much as feasible all flaw initiation sites before the heat treatment. This phase one objective is to collect initial data on a simplified mock-up and then to compare the experimental ultrasonic data with the results of simulations performed by CIVA, a computer simulation package. The area of interest is the region with the highest stress between the blade and the web. A welded T-joint coupon made of UNS S41500 was manufactured to represent this high-stress area. During the FCAW welding process, ceramic beads were embedded in the weld to create discontinuities whose size is in the critical range to initiate a crack. Inspection of the material was carried out by various nondestructive testing (NDT) methods namely conventional pulse-echo, phased array, total focusing method (TFM). With these results, detection rates were obtained in order to compare the effectiveness of each method.

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