Characterizing the Wave Environment in the Fatigue Analysis of Flexible Risers

2005 ◽  
Vol 128 (2) ◽  
pp. 108-118 ◽  
Author(s):  
John M. Sheehan ◽  
Frank W. Grealish ◽  
Annette M. Harte ◽  
Russell J. Smith
Keyword(s):  
Cost Effective ◽  
Critical Issue ◽  
Fatigue Analysis ◽  
Flexible Pipes ◽  
Water Developments ◽  
Key Issues ◽  
Flexible Risers ◽  
Offshore Industry ◽  
Unbonded Flexible Pipes

As the offshore industry moves towards deeper water developments and continues to embrace harsh environments, unbonded flexible pipes are increasingly being utilized as a cost effective riser solution. Furthermore, with the advent of issues such as nonpristine annuli environments, the fatigue performance of these flexible risers is becoming a critical issue. This paper presents an overview of the comparisons between deterministic and stochastic global fatigue analysis techniques. Methods used to perform both deterministic and stochastic analyses are outlined, from performing the global analyses to using local models to generate armor wire stresses and subsequent fatigue damage. The paper identifies the key issues in the analysis performed and presents key results and conclusions with regard to the characterization of the wave environment in the global fatigue analysis of flexible risers.

Characterisation of the Wave Environment in the Fatigue Analysis of Flexible Risers

2005 ◽  
Author(s):  
John M. Sheehan ◽  
Frank W. Grealish ◽  
Russell J. Smith ◽  
Annette M. Harte
Keyword(s):  
Cost Effective ◽  
Critical Issue ◽  
Fatigue Analysis ◽  
Harsh Environments ◽  
Flexible Pipes ◽  
Water Developments ◽  
Key Issues ◽  
Flexible Risers ◽  
Offshore Industry ◽  
Unbonded Flexible Pipes

As the offshore industry moves towards deeper water developments and continues to embrace harsh environments, unbonded flexible pipes are increasingly being utilised as a cost effective riser solution. Furthermore, with the advent of issues such as non-pristine annuli environments, the fatigue performance of these flexible risers is becoming a critical issue. This paper presents an overview of the comparisons between deterministic and stochastic global fatigue analysis techniques. Methods used to perform both deterministic and stochastic analyses are outlined, from performing the global analyses to using local models to generate armour wire stresses and subsequent fatigue damage. The paper identifies the key issues in the analysis performed and presents key results and conclusions with regard to the characterisation of the wave environment in the global fatigue analysis of flexible risers.

Numerical investigation of friction joint between Basalt Fiber Reinforced Composites and aluminum

2016 ◽  
Vol 231 (5) ◽  
pp. 543-551
Author(s):  
Andrei Costache ◽  
Christian Berggreen ◽  
Ion Marius Sivebæk ◽  
Kristian Glejbøl
Keyword(s):  
Finite Element ◽  
Basalt Fiber ◽  
Element Model ◽  
Fiber Reinforced ◽  
Pullout Force ◽  
Flexible Pipes ◽  
The Coefficient Of Friction ◽  
Flexible Risers ◽  
Offshore Oil Industry ◽  
Unbonded Flexible Pipes

Flexible risers are used in the offshore oil industry for exporting hydrocarbons from subsea equipment to floating production and storage vessels. The latest research in unbonded flexible pipes aims to reduce weight by replacing metal components with composite materials. This would result in lighter and stiffer flexible risers, which would be well suited for ultra deep water applications. This paper develops a new finite element model used for evaluating the efficiency of anchoring flat unidirectional fiber reinforced tendons in a mechanical grip. It consists two flat grips with the fiber reinforced tendon in between. The grips are pressed against the composite and the pullout force is ensured through friction. The novelty of the paper is represented by the detailed investigation of the influence between the coefficient of friction and the pullout force. By comparing numerical and experimentally obtained results, it is possible to show the importance of friction decay in the grip. Improper contact between the grips and composite is also taken into account and leads to good agreement between numerical and experimental results. This study shows how to avoid over-estimating the efficiency of such grip by using dry friction in finite element models.

Safety Factors for Fatigue Analysis of Flexible Pipes Based on Structural Reliability

2012 ◽  
Author(s):  
Fernando dos Santos Loureiro Filho ◽  
Edison Castro Prates de Lima ◽  
Luís Volnei Sudati Sagrilo ◽  
Fernando Jorge Mendes de Sousa ◽  
Carlos Alberto Duarte de Lemos
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Fatigue Analysis ◽  
Design Criterion ◽  
Flexible Riser ◽  
Safety Factors ◽  
Common Procedure ◽  
Flexible Pipes ◽  
Campos Basin ◽  
Flexible Risers

Structural reliability–based methodology [1,2] has been proposed for fatigue analysis of flexible pipes tension armours. In this methodology a design criterion is verified using a standard reliability analysis approach and checking if the fatigue failure probability is equal to or less than a target value. The use of reliability analysis in the every day design practice is not yet a common procedure. Hence, in this paper we present the calibration of safety factors for Brazilian environmental conditions to be used in the standard fatigue analysis of flexible riser tension armours. The calibration is performed in order to guarantee the same target probability of failure. The safety factors are calibrated considering four flexible risers, two connected to FPSOs and the other two to semi-submersibles located in different water depths in Campos Basin offshore Brazil.

A Collaborative Approach to Upgrading to Limits of Technology at the York River Treatment Plant

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
I. Venner ◽  
J. Husband ◽  
J. Noonan ◽  
A. Nelson ◽  
D. Waltrip
Keyword(s):  
Chesapeake Bay ◽  
Phase 1 ◽  
Treatment Plant ◽  
Cost Effective ◽  
Design Flow ◽  
Nutrient Reduction ◽  
York River ◽  
Hampton Roads ◽  
Key Issues ◽  
Virginia Department

In response to rapid population growth as well as to address the nutrient reduction goals for the Chesapeake Bay established by the Virginia Department of Environmental Quality (VDEQ), the Hampton Roads Sanitation District (HRSD) initiated the York River Treatment Plant (YRTP) Expansion Phase 1 project. The existing YRTP is a conventional step-feed activated sludge plant and is rated for an average daily design flow of 57 million liters per day (MLD). This project proposes to expand the existing treatment capacity to 114 MLD and to reduce the nutrients discharged to the York River, a tributary for the Chesapeake Bay. In order to meet the effluent limits set by the VDEQ, a treatment upgrade to limit of technology (LOT) or enhanced nutrient removal (ENR) was required. Malcolm Pirnie worked with HRSD and the VDEQ to develop and evaluate ENR process alternatives to achieve the required effluent limits with the goal of determining the most reliable and cost effective alternative to achieve the aggressive nutrient reduction goals. This paper will highlight the key issues in determining the most desirable treatment process considering both economic and non-economic factors.

Monitoring of Petroleum-Related Environmental Contamination Using Fluorescence Fingerprinting

2006 ◽  
Vol 1 (2) ◽  
Author(s):  
P. Literathy ◽  
M. Quinn
Keyword(s):  
Environmental Contamination ◽  
Statistical Evaluation ◽  
Oil Pollution ◽  
Emission Spectra ◽  
Cost Effective ◽  
Petroleum Products ◽  
Danube River ◽  
Aromatic Components ◽  
Analytical Approaches

Petroleum and its refined products are considered the most complex contaminants frequently impacting the environment in significant quantities. They have heterogeneous chemical composition and alterations occur during environmental weathering. No single analytical method exists to characterize the petroleum-related environmental contamination. For monitoring, the analytical approaches include gravimetric, spectrometric and chromatographic methods having significant differences in their selectivity, sensitivity and cost-effectiveness. Recording fluorescence fingerprints of the cyclohexane extracts of the water, suspended solids, sediment or soil samples and applying appropriate statistical evaluation (e.g. by correlating the concatenated emission spectra of the fingerprints of the samples with arbitrary standards (e.g. petroleum products)), provides a powerful, cost-effective analytical tool for characterization of the type of oil pollution and detecting the most harmful aromatic components of the petroleum contaminated matrix. For monitoring purposes, the level of the contamination can be expressed as the equivalent concentration of an appropriate characteristic standard, based on the fluorescence intensities at the relevant characteristic wavelengths. These procedures are demonstrated in the monitoring of petroleum-related pollution in the water and suspended sediment in the Danube river basin

Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar
Keyword(s):  
Green Synthesis ◽  
Color Change ◽  
Limit Of Detection ◽  
Aqueous Media ◽  
Suitable Condition ◽  
Cost Effective ◽  
Spectroscopic Studies ◽  
Calibration Plot ◽  
First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

scholarly journals Electrochemical Biosensors in Food Safety: Challenges and Perspectives

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2940
Author(s):  
Antonella Curulli
Keyword(s):  
Food Industry ◽  
Electrochemical Sensors ◽  
Cost Effective ◽  
Electrochemical Biosensors ◽  
Food Chains ◽  
Sensing Systems ◽  
Highly Sensitive ◽  
Skilled Personnel ◽  
Recent Developments ◽  
Key Issues

Safety and quality are key issues for the food industry. Consequently, there is growing demand to preserve the food chain and products against substances toxic, harmful to human health, such as contaminants, allergens, toxins, or pathogens. For this reason, it is mandatory to develop highly sensitive, reliable, rapid, and cost-effective sensing systems/devices, such as electrochemical sensors/biosensors. Generally, conventional techniques are limited by long analyses, expensive and complex procedures, and skilled personnel. Therefore, developing performant electrochemical biosensors can significantly support the screening of food chains and products. Here, we report some of the recent developments in this area and analyze the contributions produced by electrochemical biosensors in food screening and their challenges.

scholarly journals Semi-automated regional classification of the style of activity of slow rock-slope deformations using PS InSAR and SqueeSAR velocity data

Landslides ◽  
2021 ◽  
Author(s):  
Chiara Crippa ◽  
Elena Valbuzzi ◽  
Paolo Frattini ◽  
Giovanni B. Crosta ◽  
Margherita C. Spreafico ◽  
...  
Keyword(s):  
Rock Slope ◽  
Progressive Failure ◽  
Principal Component ◽  
Cost Effective ◽  
Displacement Rate ◽  
Machine Learning Classification ◽  
Management Perspective ◽  
Alpine Environments

AbstractLarge slow rock-slope deformations, including deep-seated gravitational slope deformations and large landslides, are widespread in alpine environments. They develop over thousands of years by progressive failure, resulting in slow movements that impact infrastructures and can eventually evolve into catastrophic rockslides. A robust characterization of their style of activity is thus required in a risk management perspective. We combine an original inventory of slow rock-slope deformations with different PS-InSAR and SqueeSAR datasets to develop a novel, semi-automated approach to characterize and classify 208 slow rock-slope deformations in Lombardia (Italian Central Alps) based on their displacement rate, kinematics, heterogeneity and morphometric expression. Through a peak analysis of displacement rate distributions, we characterize the segmentation of mapped landslides and highlight the occurrence of nested sectors with differential activity and displacement rates. Combining 2D decomposition of InSAR velocity vectors and machine learning classification, we develop an automatic approach to characterize the kinematics of each landslide. Then, we sequentially combine principal component and K-medoids cluster analyses to identify groups of slow rock-slope deformations with consistent styles of activity. Our methodology is readily applicable to different landslide datasets and provides an objective and cost-effective support to land planning and the prioritization of local-scale studies aimed at granting safety and infrastructure integrity.

scholarly journals Variable Temperature Synthesis of Tunable Flame-Generated Carbon Nanoparticles

2021 ◽  
Vol 7 (2) ◽  
pp. 44
Author(s):  
Francesca Picca ◽  
Angela Di Pietro ◽  
Mario Commodo ◽  
Patrizia Minutolo ◽  
Andrea D’Anna
Keyword(s):  
Carbon Nanoparticles ◽  
Variable Temperature ◽  
Flame Temperature ◽  
Cost Effective ◽  
Synthesis Process ◽  
Electrical Mobility ◽  
Material Synthesis ◽  
Online Measurements ◽  
Degree Of Graphitization

In this study, flame-formed carbon nanoparticles of different nanostructures have been produced by changing the flame temperature. Raman spectroscopy has been used for the characterization of the carbon nanoparticles, while the particle size has been obtained by online measurements made by electrical mobility analysis. The results show that, in agreement with recent literature data, a large variety of carbon nanoparticles, with a different degree of graphitization, can be produced by changing the flame temperature. This methodology allows for the synthesis of very small carbon nanoparticles with a size of about 3-4 nm and with different graphitic orders. Under the perspective of the material synthesis process, the variable-temperature flame-synthesis of carbon nanoparticles appears as an attractive procedure for a cost-effective and easily scalable production of highly tunable carbon nanoparticles.

scholarly journals Graphene, an Interesting Nanocarbon Allotrope for Biosensing Applications: Advances, Insights, and Prospects

2021 ◽  
Vol 12 ◽  
pp. 117959722098382
Author(s):  
Farid Menaa ◽  
Yazdian Fatemeh ◽  
Sandeep K Vashist ◽  
Haroon Iqbal ◽  
Olga N Sharts ◽  
...  
Keyword(s):  
Cost Effective ◽  
Genetic Alterations ◽  
Multiplex Detection ◽  
Quantitative Characterization ◽  
Disease Biomarkers ◽  
Qualitative And Quantitative ◽  
Sensing Systems ◽  
Doped Graphene ◽  
Bioanalytical Applications

Graphene, a relatively new two-dimensional (2D) nanomaterial, possesses unique structure (e.g. lighter, harder, and more flexible than steel) and tunable physicochemical (e.g. electronical, optical) properties with potentially wide eco-friendly and cost-effective usage in biosensing. Furthermore, graphene-related nanomaterials (e.g. graphene oxide, doped graphene, carbon nanotubes) have inculcated tremendous interest among scientists and industrials for the development of innovative biosensing platforms, such as arrays, sequencers and other nanooptical/biophotonic sensing systems (e.g. FET, FRET, CRET, GERS). Indeed, combinatorial functionalization approaches are constantly improving the overall properties of graphene, such as its sensitivity, stability, specificity, selectivity, and response for potential bioanalytical applications. These include real-time multiplex detection, tracking, qualitative, and quantitative characterization of molecules (i.e. analytes [H2O2, urea, nitrite, ATP or NADH]; ions [Hg2+, Pb2+, or Cu2+]; biomolecules (DNA, iRNA, peptides, proteins, vitamins or glucose; disease biomarkers such as genetic alterations in BRCA1, p53) and cells (cancer cells, stem cells, bacteria, or viruses). However, there is still a paucity of comparative reports that critically evaluate the relative toxicity of carbon nanoallotropes in humans. This manuscript comprehensively reviews the biosensing applications of graphene and its derivatives (i.e. GO and rGO). Prospects and challenges are also introduced.

Sign in / Sign up

Export Citation Format

Share Document