Improving Mooring Integrity through Standardized Inspection Practices – A DeepStar® 19403 Project

2021 ◽  
Author(s):  
KT Ma ◽  
Robert Spong ◽  
Daniel DeBroeck ◽  
Didier L’Hostis ◽  
Øystein Gabrielsen ◽  
...  
Keyword(s):  
Visual Inspection ◽  
System Capacity ◽  
Mooring Line ◽  
Critical Element ◽  
Guidance Document ◽  
Destructive Testing ◽  
Operating Life ◽  
Premature Failure ◽  
Inspection Work ◽  
Service Inspection

Abstract In-service inspection is a critical element in confirming the integrity of permanent floating production unit mooring systems. Over the unit's operating life, which will typically span 20 years or more, these inspections provide the majority of the condition information on the mooring components and overall system. This information enables operators to proactively address mooring issues caused by degradation mechanisms or deviations in mooring line tensions that could reduce the system capacity and potentially result in premature failure. However, detailed guidance on inspection intervals, and in particular inspection scope, is limited for permanent mooring systems. To address this identified industry need, the DeepStar® technology consortium initiated Project 19403, "Improving Mooring Integrity through Standardized Inspection and Fit-For-Service Assessment" to develop best inspection practice guidance for permanent mooring systems [1]. This paper describes the content and benefits of this new mooring inspection guidance document developed as part of the DeepStar® 19403 project [1] with the support of subject matter experts from major operator companies, Class societies and mooring consultancies. The paper will describe how this new guidance compliments and expands current industry Recommended Practice (RP) guidance. Key aspects related to in-service survey intervals, component inspection work scopes and inspection methods will be discussed as well as the execution planning of in-service mooring inspections. To facilitate inspection work, the predominate deterioration mechanisms are introduced which are corrosion, wear and fatigue. Other types of deteriorations are also summarized. Default in-service survey intervals (frequencies) and component inspections are recommended. In-service inspection methods are reviewed, from General Visual Inspection (GVI) and Close Visual Inspection (CVI) to advanced Non-Destructive Testing (NDT). Guidance on assessing the residual capacity of a damaged or flawed mooring component, known as fitness-for-service, is also covered within the new mooring inspection guidance.

Quality Assurance of Laser Welded Axisymmetric Sandwich Structure

2013 ◽  
Vol 549 ◽  
pp. 529-534 ◽  
Author(s):  
Kimmo Illikainen ◽  
Kalle Holappa ◽  
Kari Mäntyjärvi
Keyword(s):  
Quality Assurance ◽  
Working Conditions ◽  
Sandwich Structure ◽  
Visual Inspection ◽  
Experimental Tests ◽  
The Body ◽  
Destructive Testing ◽  
Great Strength ◽  
Static Tests

This study focuses on quality assurance in a laser welded axisymmetric sandwich structure that functions as the body of an electric machine. The manufacturing quality of the structure was measured using destructive testing and visual inspection. The destructive tests included both fatigue and static tests in addition to a macrographic examination. The visual inspection comprised ocular estimates of the laser welded seams as well as their requirements. Compared with the real working conditions of the machine, the experimental tests were exhaustive. Nevertheless, in the tests, the bodies held up very well which shows the great strength of the structure.

Mooring Chain Fatigue Assessment Methodology and Software of Williams Gulfstar 1 Spar Platform Using Comparison Between Field Measured Data and the Design Basis Information

2015 ◽  
Author(s):  
Young-Chan (Y. C.) Park ◽  
Arun Antony ◽  
Hisham Moideen ◽  
Arada Jamnongpipatkul ◽  
Jinsang Hwang ◽  
...  
Keyword(s):  
Fatigue Damage ◽  
Environmental Conditions ◽  
Measured Data ◽  
Design Parameters ◽  
Mooring Line ◽  
Graphic User Interface ◽  
Mooring System ◽  
Operating Life ◽  
Design Data ◽  
Mooring Chain

In 2014 Williams Companies delivered a Spar-based FPS to be used by the Hess Corporation for developing their “Tubular Bells” field as well as for future tiebacks for other developments. Tubular Bells is located in the Mississippi Canyon region of the Gulf of Mexico. The Spar hull is the ‘Classic hull form’, 584 ft (178 m) long, 85 ft (26 m) in diameter with 60 ft (18 m) hull freeboard. The mooring system consists of 9 mooring lines in 3 groups composed of a chain-polyester-chain configuration. This paper describes the tools and methodology Williams plans to use for assessing the fatigue damage of the mooring chain over the operating life of the platform. The basic plan is to collect field-measured data for parameters that impact mooring fatigue damage, such as: environmental conditions, Spar motions (particularly Vortex Induced Motions data) and mooring line tensions, then process that data with specialized software so it can be effectively compared to the applicable data that was used in the design of the mooring system for fatigue. A key element in the plan to compare the field data with the design data is new computer software developed specifically to process the field measured data and generate the field measured, fatigue design parameters on a regular basis and in a form that is readily comparable to the design data. Additionally, a graphic user interface in this software will provide a clear visualization of the Spar motions that is linked with the associated environmental conditions for the same time periods.

scholarly journals Design and Development of Aircraft Propeller Maintenance Facility for General Aviation

Khazanah ◽  
2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Amman Mujahid ◽  
Keyword(s):  
Environmental Impact ◽  
Visual Inspection ◽  
General Aviation ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Proactive Approach ◽  
Maintenance Techniques ◽  
Set Up ◽  
Environment Sustainability ◽  
Non Destructive

Since the first flight and introduction of propellers from marine to the sky, various maintenance techniques have been employed to maintain aircraft propellers. With the advancement in the operation and safety of flight, propellers have been manufactured in various materials, shapes and measurements. The design developed is based on the concept of a “single stop shop facility”. The propeller maintenance facility majorly focuses the general aviation in order to provide them a set up that primarily focuses on the maintenance of propellers in order to avoid malfunctions resulting in accidents and failures. The maintenance procedures for workbench include static balancing, blade tracking, cleaning, visual inspection, corrosion removal and Non-Destructive Testing (NDT). The developed facility has an accelerated scalability with the provision of facilitating Non-Destructive Testing that is performed on the workbench. The non-destructive testing results in assuring reliability and safety of the propellers as per the modern maintenance practices. The workbench developed focuses over the environment sustainability as it functions on the concept of sustainable maintenance that involves reduced unnecessary maintenance. Moreover, the currently developed facility integrates a proactive approach involving reduced use of energy in order to produce less waste and environmental impact. At present, the workbench has been manufactured and is being tested for propeller maintenance procedures.

scholarly journals Evidence collected for peer review of buckling-restrained braced frames in New Zealand

2021 ◽  
Vol 54 (3) ◽  
pp. 197-210
Author(s):  
Dan Court-Patience ◽  
Mark Garnich
Keyword(s):  
New Zealand ◽  
Peer Review ◽  
Guidance Document ◽  
Braced Frames ◽  
Premature Failure ◽  
Regulatory Standards ◽  
Global Buckling ◽  
Buckling Restrained Braced Frames ◽  
Strength And Stiffness ◽  
Bracing System

Buckling-restrained braces (BRBs) form a bracing system that provides lateral strength and stiffness to a building. These systems have been shown to provide larger energy dissipation in severe earthquake events compared to concentrically and eccentrically braced frames (CBFs and EBFs). However, unlike CBFs and EBFs there is no guidance document or specific instructions in regulatory standards for the design of buckling-restrained braced frames (BRBFs) in New Zealand. This makes it difficult for structural engineers to be aware of all the strength and stability considerations required for the safe design of BRBFs. Currently, structural designs that include BRBFs require a peer-review to gain building compliance. The American standard ANSI/AISC 341-16 is the adopted document used in New Zealand for guidance in how to collect evidence showing a BRBF system will perform as intended. However, as ANSI/AISC 341-16 is not a governing document in New Zealand, instructions within the document are not enforced and can be made to fit within the constraints of a building project. By way of example, this paper presents the experimental test process and results acquired from pre-qualification testing of three different commercially available BRB architypes. Of the three BRB designs investigated, one failed prematurely due to global buckling. A manufacturing error was the likely cause of this premature failure. This failure highlights the need for strict quality control during fabrication. All remaining BRBs performed well, meeting the acceptance criteria set out in ANSI/AISC 341-16. Positive pre-qualification results meant the BRBs were installed in medium to high-rise buildings throughout New Zealand. The importance of sub-assemblage testing to assess the performance of a BRB and its frame components is also discussed. Finally, the capability of high fidelity modelling to supplemental physical testing is also presented.

Study on the Indication Processing Method for the In-Service Inspection Based on RSE-M

2017 ◽  
Author(s):  
Xia Peng ◽  
Zhang Xueliang ◽  
Yang Cheng ◽  
Zeng Qingyue
Keyword(s):  
Growth Analysis ◽  
Processing Method ◽  
Defect Characterization ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Deviation Analysis ◽  
Key Technologies ◽  
Non Destructive ◽  
Service Inspection ◽  
Processing Solution

For the defect examined by non-destructive testing during in-service inspection, it shall be subject to a set of operations known as indication processing, which aim to identify and analyze a deviation situation, confirm whether or not this is a genuine defect and select the best processing solution. This paper is intended to illustrate an indication processing methodology that provides guidance on performing indication processing. Firstly, an indication processing method which covers indication identifying, deviation analysis, solution assessment, and solution implementation is specified. And then, some key technologies such as defect characterization, fatigue crack growth analysis applied in the indication processing methodology are descripted. Finally, some preliminary thinking is presented during introducing the indication processing methodology and some technical suggestions are also provided to perfect the methodology for providing better reference during application on PWRs in China. Actually, the study in this paper is preliminary and more research is needed to be done in the future.

Visual Inspection on Premature Failure of Electric Motor Bearings

2011 ◽  
Vol 84-85 ◽  
pp. 557-561
Author(s):  
Agus Geter Edy Sutjipto ◽  
A. Triwiyanto ◽  
Yulfian Aminanda ◽  
Waleed Fekry Faris ◽  
Erry Yulian Triblas Adesta
Keyword(s):  
Electric Motor ◽  
Visual Inspection ◽  
Premature Failure ◽  
Bearing Clearance ◽  
Electric Erosion ◽  
Equal Spacing

All electrical motor or generator bearings can potential suffers from electric erosion. Unfortunately, problems can start after just a few months of running a new electric motor or generator. From visual inspection, it was found that the failure happened on the raceway surface in equal spacing. There may be many reasons for this – heavier loading than has been anticipated, inadequate or unsuitable lubrication, careless handling, ineffective sealing, or fits that are too tight, with resultant insufficient internal bearing clearance. Each of these factors produces its own particular type of damage and leaves its own special imprint on the bearing. Consequently, by examining a damaged bearing such as visual inspection, it is possible, in the majority of cases, to form an opinion on the cause of the damage and to take the requisite action to prevent a recurrence.

scholarly journals Steel quality of rolling contact bearings produced by different manufacturers, used for mining equipment instrumentation

2021 ◽  
Vol 315 ◽  
pp. 03019
Author(s):  
Aleksandr Korotkov ◽  
Lidiya Korotkova ◽  
Stefan Voeth ◽  
Roman Solentsov
Keyword(s):  
Quality Control ◽  
Negative Impact ◽  
Bearing Steel ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Mining Equipment ◽  
Operating Life ◽  
Premature Failure ◽  
Steel Quality

Severe operating conditions of mining equipment have a negative impact on the operating life of the rolling contact bearings used in such equipment. The main reasons for the premature failure of rolling contact bearings include, first of all, poor quality of the bearing steel as delivered and the defects of their subsequent heat treatment. The abovementioned reasons result in splitting of bearings, metal shelling and appearance of potholes on their tracks, as well as intense abrasive wear. Nevertheless, despite the importance of this issue, the quality of bearing steel, either as delivered or in finished bearings, is usually not under control.To solve this problem, the quality of bearing steel was studied, exemplified by the bearings of the Russian, Swedish (SKF) and Japanese (NSK) manufacturers, i.e., main suppliers of rolling contact bearings for mining equipment in Russia. The problem of bearing steel quality control was solved by developing a quality control methodology that took into account the state of the metal after metallurgical treatment and at the stage of bearing production. Based on this methodology, the main types of bearing steel defects affecting the mechanism of bearing failure are identified.It is found that the bearing steel quality of domestic manufacturers is highly competitive with foreign counterparts. A method of nondestructive control is also proposed for detecting possible microstructure defects in bearings, either as delivered or while in operation.

scholarly journals Uncertainty in condition prediction of bridges based on assessment method – case study in Estonia

2019 ◽  
Author(s):  
Sander Sein ◽  
Juhan Idnurm ◽  
José C. Matos
Keyword(s):  
Continuous Time ◽  
Visual Inspection ◽  
Assessment Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Inference Procedure ◽  
Wrong Decision ◽  
Traditional Assessment ◽  
Non Destructive

<p>In this paper the uncertainty in condition assessment based on most common assessment methods, visual inspection and non-destructive testing, is investigated. For decision-making the averaged or estimated value is suitable, but if the basis of a decision is only a subjective visual inspection, then it could lead to a wrong decision. The second most traditional assessment method is non-destructive testing (NDT), which can give reliable results, but the interpretation of measurement is needed. To investigate the errors in both evaluations, benchmarking tests were carried out in Estonia within two groups, a group of experienced inspectors and a group of unexperienced students, to show how the importance of experience affects results. To present the influence of assessment uncertainty to condition prediction curves based on continuous-time Markov model are calculated and for updating, Bayesian inference procedure is used.</p>

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