ECA Methodology for Fatigue Design of Risers and Flowlines

2007 ◽  
Author(s):  
C. H. Luk ◽  
T. J. Wang
Keyword(s):  
Fracture Mechanics ◽  
Design Method ◽  
Steel Catenary Riser ◽  
Fatigue Design ◽  
Wide Range ◽  
Fatigue And Fracture ◽  
Level 3 ◽  
Fatigue Loads ◽  
Vessel Motion ◽  
Level 2

Engineering Criticality Assessment (ECA) is a procedure based on fracture mechanics that may be used to supplement the traditional S-N approach and determine the flaw acceptance and inspection criteria in fatigue and fracture design of risers and flowlines. A number of design codes provide guidance for this procedure, e.g. BS-7910:2005 [1]. However, more investigations and example studies are still needed to address the design implications for riser and flowline applications. This paper provides a review of the existing ECA methodology, presents a fracture mechanics design method for a wide range of riser and flowline fatigue problems, and shows flaw size results from steel catenary riser (SCR) and flowline (FL) examples. The first example is a deepwater SCR subjected to fatigue loads due to vessel motion and riser VIV. The second example is a subsea flowline subjected to thermal fatigue loads. The effects of crack re-characterization and material plasticity on the Level-2 and Level-3 ECA results of the SCR and flowline examples are illustrated.

scholarly journals A Fracture Mechanics-Based Optimal Fatigue Design Method of Under-Matched HSLA Steel Butt-Welded Joints with Imperfections

2019 ◽  
Vol 9 (17) ◽  
pp. 3609 ◽  
Author(s):  
Wen ◽  
Wang ◽  
Dong ◽  
Fang
Keyword(s):  
Fracture Mechanics ◽  
Welded Joints ◽  
Design Method ◽  
Hsla Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Engineering Structures ◽  
Fatigue Design ◽  
Load Carrying ◽  
Practical Engineering

The trend of light-weight structures leads to the wide application of high strength steels in engineering structures. When welding high strength steels, under-matched consumables could reduce the cold-cracking tendency, simplifying the preheating process. However, under-matched welds would sometimes make the high strength base metal pointless due to its weak load-carrying capacity. For the purpose of enhancing the fatigue strength of under-matched welded joints, a fracture mechanics-based optimal fatigue design method of under-matched butt-welded joints is proposed in this work. Heterogeneous mechanical features of welded joints, which are not considered in current standards and codes, are incorporated into the optimal design method. The fatigue limit of the high strength parent metal is taken as the design target, which has seldom been reported. HSLA steel Q550, with its under-matched consumable ER70S-6 composed X-shaped butt-welds, is selected for experimental verification. The experimental results indicate that the fracture mechanic based equal-fatigue-bearing-capacity (EFBC) design method established in this work is feasible and could be a valuable reference for the design of practical engineering structures.

Proposed Modifications to API 579 Part 3 Brittle Fracture Screening Procedures

2019 ◽  
Author(s):  
Brian R. Macejko ◽  
Seetha Ramudu Kummari ◽  
Phillip E. Prueter
Keyword(s):  
Fracture Mechanics ◽  
Brittle Fracture ◽  
State Of The Art ◽  
Acceptance Criteria ◽  
Evaluation Procedures ◽  
Failure Assessment ◽  
Level 3 ◽  
Screening Procedures ◽  
Level 1 ◽  
Level 2

Abstract Significant inconsistencies and inadequacies exist in the current brittle fracture screening procedures in the 2016 edition of API 579-1/ASME FFS-1, Fitness-For-Service (API 579). Results from an evaluation completed using the current published guidance could prove unsafe in some instances. The ASME/API Joint Committee on Fitness-For-Service (FFS) recently initiated a project to rewrite API 579 Part 3, Assessment of Existing Equipment for Brittle Fracture. The intent of the project is to establish new Level 1 and Level 2 evaluation procedures and acceptance criteria developed using state-of-the-art fracture mechanics consistent with the Part 9 Failure Assessment Diagram (FAD) approach, currently employed in Level 3 FFS evaluations. This paper will provide a comprehensive summary of deficiencies and concerns with current published methods for evaluating susceptibility of pressure equipment to potential brittle fracture failures. Additionally, the paper will provide an overview of the methodology employed in the recently proposed procedure modifications for Part 3 of API 579 to mitigate the current deficiencies.

scholarly journals Introducing a clerkship curriculum based on entrustable professional activities: a pilot study

2020 ◽  
Author(s):  
Severin Pinilla ◽  
Andrea Cantisani ◽  
Stefan Klöppel ◽  
Werner Strik ◽  
Christoph Nissen ◽  
...  
Keyword(s):  
Pilot Study ◽  
Entrustable Professional Activities ◽  
Professional Activities ◽  
Wide Range ◽  
Level 3 ◽  
Self Assessments ◽  
Level 1 ◽  
Indirect Supervision ◽  
Level 2 ◽  
Patient Mix

Abstract BackgroundGeneral clerkship quality criteria have not been studied after introducing a curriculum based on entrustable professional activities (EPAs). Therefore, we conducted a pilot study to explore educational outcomes of an EPA-based clerkship curriculum reform.MethodsWe collected multiple self-assessment and evaluation data on levels 1-3 of the New World Kirkpatrick model (KPM). For level 1 (reaction) we analyzed curriculum evaluations and verbal and written students’ feedback. For level 2 (learning) pre- and post-clerkship self-assessments of perceived need for supervision for each EPA and students’ written learning reflections based on patient mix exposure were analyzed. For level 3 (behavior) we evaluated workplace-based assessments.ResultsThe first student cohort in the new EPA-based clerkship completed 180 self-assessments (18 per student) of need for supervision and 63 documented workplace-based assessments (average of 6.3 per student in four weeks). On KPM level 1 we saw a high overall satisfaction with the clerkship (average of 4.9, range: 4.0-5.0 on a 5-point Likert scale). In written evaluations and feedback rounds students pointed out the importance of structured bedside teaching in the first clerkship week. On KPM level 2 the overall decrease of self-assessed need for supervision before and after the clerkship was two supervision levels (from direct to indirect supervision) and statistically significant (p < 0.05). For three EPAs students reached indirect supervision levels. Learning reflections and patient mix analysis indicated that students were exposed to a wide range of diagnostic categories (ICD-10: F0 – F6) and received actionable feedback for communication skills. On KPM level 3 clinical supervisors predominantly used EPAs 1 (History taking), 2 (Assessing mental status) and 8 (Documentation and presentation) for workplace-based assessments. We saw a decreasing need for supervision from the first to the last week in the clerkship according to the supervisors’ judgements.ConclusionStudents reacted positively to introducing an EPA-based clerkship curriculum. The EPA-oriented formative self-assessments and workplace-based assessments seemed to support achievement of competency-based learning goals. However, more in-depth understanding of the entrustment process in the clerkship context is necessary to fully leverage the potential of an EPA-based clerkship.

Thunder Hawk Riser System Design: An Integrated Experience

2010 ◽  
Author(s):  
Peimin Cao ◽  
Sherry Xiang ◽  
Luc Chabot ◽  
Paul Fourchy ◽  
Rafik Boubenider
Keyword(s):  
System Design ◽  
Integrated Design ◽  
Sensitivity Analyses ◽  
Design Parameters ◽  
Analysis Model ◽  
Steel Catenary Riser ◽  
Fatigue Design ◽  
Fatigue And Fracture ◽  
Riser Design ◽  
Scr System

The Thunder Hawk field was developed through a Steel Catenary Riser (SCR) system connected to a DeepDraft Semi® Floating Production Unit (FPU) installed in approximately 6,060-ft. water depth in the central Gulf of Mexico (GoM). This paper presents an integrated riser design experience, focusing on the significant design challenges and solutions. The Thunder Hawk FPU was one of the first deepwater projects to address the enhanced GoM environment criteria. These criteria required the integrated design team to configure a feasible and robust hull, mooring and riser system. Model tests were performed to validate the design and calibrate the analysis model. Other challenges included the SCR fatigue and fracture design, titanium stress joint and receptacle design for the high pressure production risers, flex joint over-rotation design, and porch fatigue design. A significant amount of sensitivity analyses were performed to cover the uncertainty of the various hull, mooring, and riser design parameters that affected the SCR performance. The SBM Atlantia (SBMA) riser team worked closely with the Murphy Integrated Project Team (IPT) to achieve a robust and comprehensive riser design 16 months before the first SCR was installed. The highly integrated engineering approach enabled prompt and full considerations of the system interactions, and provided instant design evaluation throughout the project. The sensitivity analyses established the system design envelopes, and resulted in significant flexibility in offshore installation and operation.

Historical text archives and prosopography: the COEL database system

1998 ◽  
Vol 10 (1-3) ◽  
pp. 57-72 ◽  
Author(s):  
K. S. B. Keats-Rohan
Keyword(s):  
Research Tool ◽  
Direct Access ◽  
Specific Situation ◽  
Core Data ◽  
Secondary Sources ◽  
The Core ◽  
Level 3 ◽  
Full Discussion ◽  
Available Information ◽  
Level 2

The COEL database and database software, a combined reference and research tool created by historians for historians, is presented here through Screenshots illustrating the underlying theoretical model and the specific situation to which that has been applied. The key emphases are upon data integrity, and the historian's role in interpreting and manipulating what is often contentious data. From a corpus of sources (Level 1) certain core data are extracted for separate treatment at an interpretive level (Level 3), based upon a master list of the core data (Level 2). The core data are interdependent: each record in Level 2 is of interest in itself; and it either could or should be associated with an(other) record(s) as a specific entity. Sometimes the sources are ambiguous and the association is contentious, necessitating a probabilty-coding approach. The entities created by the association process can then be treated at a commentary level, introducing material external to the database, whether primary or secondary sources. A full discussion of the difficulties is provided within a synthesis of available information on the core data. Direct access to the source texts is only ever a mouse click away. Fully query able, COEL is formidable look-up and research tool for users of all levels, who remain free to exercise an alternative judgement on the associations of the core data. In principle, there is no limit on the type of text or core data that could be handled in such a system.

EVALUASI PELATIHAN DI PT. PUPUK KUJANG CIKAMPEK

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Lania Muharsih ◽  
Ratih Saraswati
Keyword(s):  
Training Evaluation ◽  
Work Productivity ◽  
Learning Behavior ◽  
Level 3 ◽  
Level 1 ◽  
Four Levels ◽  
A Company ◽  
Level 2 ◽  
Evaluation Sheet ◽  
Assessment Factor

This study aims to determine the training evaluation at PT. Kujang Fertilizer. PT. Pupuk Kujang is a company engaged in the field of petrochemicals. Evaluation sheet of PT. Fertilizer Kujang is made based on Kirkpatrick's theory which consists of four levels of evaluation, namely reaction, learning, behavior, and results. At level 1, namely reaction, in the evaluation sheet is in accordance with the theory of Kirkpatrick, at level 2 that is learning should be held pretest and posttest but only made scale. At level 3, behavior, according to theory, but on assessment factor number 3, quantity and work productivity should not need to be included because they are included in level 4. At level 4, that is the result, here is still lacking to get a picture of the results of the training that has been carried out because only based on answers from superiors without evidence of any documents.   Keywords: Training Evaluation, Kirkpatrick Theory.    Penelitian ini bertujuan mengetahui evaluasi training di PT. Pupuk Kujang. PT. Pupuk Kujang merupakan perusahaan yang bergerak di bidang petrokimia. Lembar evaluasi PT. Pupuk Kujang dibuat berdasarkan teori Kirkpatrick yang terdiri dari empat level evaluasi, yaitu reaksi, learning, behavior, dan hasil. Pada level 1 yaitu reaksi, di lembar evaluasi tersebut sudah sesuai dengan teori dari Kirkpatrick, pada level 2 yaitu learning seharusnya diadakan pretest dan posttest namun hanya dibuatkan skala. Pada level 3 yaitu behavior, sudah sesuai teori namun pada faktor penilaian nomor 3 kuantitas dan produktivitas kerja semestinya tidak perlu dimasukkan karena sudah termasuk ke dalam level 4. Pada level 4 yaitu hasil, disini masih sangat kurang untuk mendapatkan gambaran hasil dari pelatihan yang sudah dilaksanakan karena hanya berdasarkan dari jawaban atasan tanpa bukti dokumen apapun.   Kata kunci: Evaluasi Pelatihan, Teori Kirkpatrick.

Variation in antibiotic use across intensive care units (ICU): A population-based cohort study in Ontario, Canada

2020 ◽  
Vol 41 (9) ◽  
pp. 1035-1041
Author(s):  
Erika Y. Lee ◽  
Michael E. Detsky ◽  
Jin Ma ◽  
Chaim M. Bell ◽  
Andrew M. Morris
Keyword(s):  
Cohort Study ◽  
Intensive Care ◽  
Intensive Care Units ◽  
Ventilatory Support ◽  
Severity Of Illness ◽  
Antibiotic Use ◽  
Patient Factors ◽  
Days Of Therapy ◽  
Level 3 ◽  
Level 2

AbstractObjectives:Antibiotics are commonly used in intensive care units (ICUs), yet differences in antibiotic use across ICUs are unknown. Herein, we studied antibiotic use across ICUs and examined factors that contributed to variation.Methods:We conducted a retrospective cohort study using data from Ontario’s Critical Care Information System (CCIS), which included 201 adult ICUs and 2,013,397 patient days from January 2012 to June 2016. Antibiotic use was measured in days of therapy (DOT) per 1,000 patient days. ICU factors included ability to provide ventilator support (level 3) or not (level 2), ICU type (medical-surgical or other), and academic status. Patient factors included severity of illness using multiple-organ dysfunction score (MODS), ventilatory support, and central venous catheter (CVC) use. We analyzed the effect of these factors on variation in antibiotic use.Results:Overall, 269,351 patients (56%) received antibiotics during their ICU stay. The mean antibiotic use was 624 (range 3–1460) DOT per 1,000 patient days. Antibiotic use was significantly higher in medical-surgical ICUs compared to other ICUs (697 vs 410 DOT per 1,000 patient days; P < .0001) and in level 3 ICUs compared to level 2 ICUs (751 vs 513 DOT per 1,000 patient days; P < .0001). Higher antibiotic use was associated with higher severity of illness and intensity of treatment. ICU and patient factors explained 47% of the variation in antibiotic use across ICUs.Conclusions:Antibiotic use varies widely across ICUs, which is partially associated with ICUs and patient characteristics. These differences highlight the importance of antimicrobial stewardship to ensure appropriate use of antibiotics in ICU patients.

scholarly journals Nano-imprinted subwavelength gratings as polarizing beamsplitters

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Julian Wüster ◽  
Yannick Bourgin ◽  
Patrick Feßer ◽  
Arne Behrens ◽  
Stefan Sinzinger
Keyword(s):  
Nanoimprint Lithography ◽  
Optical Measurement ◽  
Design Method ◽  
Optical Systems ◽  
Surface Metrology ◽  
Measurement Systems ◽  
Common Path ◽  
Dielectric Coatings ◽  
Subwavelength Gratings ◽  
Wide Range

AbstractPolarizing beamsplitters have numerous applications in optical systems, such as systems for freeform surface metrology. They are classically manufactured from birefringent materials or with stacks of dielectric coatings. We present a binary subwavelength-structured form-birefringent diffraction grating, which acts as a polarizing beamsplitter for a wide range of incidence angles −30∘…+30∘. We refine the general design method for such hybrid gratings. We furthermore demonstrate the manufacturing steps with Soft-UV-Nanoimprint-Lithography, as well as the experimental verification, that the structure reliably acts as a polarizing beamsplitter. The experimental results show a contrast in efficiency for TE- and TM-polarization of up to 1:18 in the first order, and 34:1 in the zeroth order. The grating potentially enables us to realize integrated compact optical measurement systems, such as common-path interferometers.

scholarly journals An Atmospheric Visibility Grading Method Based on Ensemble Learning and Stochastic Weight Average

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 869
Author(s):  
Xiuguo Zou ◽  
Jiahong Wu ◽  
Zhibin Cao ◽  
Yan Qian ◽  
Shixiu Zhang ◽  
...  
Keyword(s):  
Ensemble Learning ◽  
Traffic Accidents ◽  
Feature Sets ◽  
Atmospheric Visibility ◽  
Average Accuracy ◽  
Level 3 ◽  
Visual Characteristics ◽  
Level 1 ◽  
Grading Model ◽  
Level 2

In order to adequately characterize the visual characteristics of atmospheric visibility and overcome the disadvantages of the traditional atmospheric visibility measurement method with significant dependence on preset reference objects, high cost, and complicated steps, this paper proposed an ensemble learning method for atmospheric visibility grading based on deep neural network and stochastic weight averaging. An experiment was conducted using the scene of an expressway, and three visibility levels were set, i.e., Level 1, Level 2, and Level 3. Firstly, the EfficientNet was transferred to extract the abstract features of the images. Then, training and grading were performed on the feature sets through the SoftMax regression model. Subsequently, the feature sets were ensembled using the method of stochastic weight averaging to obtain the atmospheric visibility grading model. The obtained datasets were input into the grading model and tested. The grading model classified the results into three categories, with the grading accuracy being 95.00%, 89.45%, and 90.91%, respectively, and the average accuracy of 91.79%. The results obtained by the proposed method were compared with those obtained by the existing methods, and the proposed method showed better performance than those of other methods. This method can be used to classify the atmospheric visibility of traffic and reduce the incidence of traffic accidents caused by atmospheric visibility.

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