Design life or service life

2021 ◽  
pp. 77-94
Author(s):  
Donald Charrett
Keyword(s):  
Service Life ◽  
Design Life

Best Practices for Minimizing Mooring Failures at the Fairlead

2014 ◽  
Author(s):  
Jonathon D. Miller ◽  
Gennine R. Kärrsten ◽  
Curt E. Haveman
Keyword(s):  
Service Life ◽  
Best Practices ◽  
Preventive Maintenance ◽  
New Technologies ◽  
Mooring System ◽  
Floating Structures ◽  
System Service ◽  
Design Life

Although preventive maintenance is not a new concept when dealing with mooring systems, experience shows that the implementation is not always successful. As important as new technologies are in improving mooring integrity, it is equally important to ensure that well-established best practices remain in place. As the industry approaches a period where extending service life of floating structures is desirable, but the existing mooring system has reached the twilight of its service life, the need for properly maintaining the mooring system is more acute. With time on their side, the prudent operator can implement small regular steps to extend mooring system service life. This paper presents methodologies to maximize design life by highlighting design and operational best practices, maintenance and monitoring, and identifying common reasons why these best practices are not implemented.

Service Life Checking Calculation of Marine Reinforced Concrete Structures Based on Monte Carlo Method

2013 ◽  
Vol 788 ◽  
pp. 663-669
Author(s):  
Gui Hong Dong ◽  
Zhi Hong Fan ◽  
Jian Bo Xiong
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Service Life ◽  
Marine Environment ◽  
Concrete Structures ◽  
Chloride Concentration ◽  
Chloride Diffusion ◽  
Distribution Model ◽  
Chloride Diffusion Coefficient ◽  
Design Life

Checking some apparent chloride diffusion coefficient of concrete in the marine environment meets the requirements of design life based on Monte Carlo method. Through the project investigations, laboratory test data, statistical analysis and to determine random distribution model of the critical chloride concentration, the surface chloride concentration ,using computer program simulation 5000 random groups critical chloride concentration, surface chloride concentration into the life value calculation model, And obtain the derived distribution of the concrete structures service life, in order to determine Compliance with the design life of concrete structures. For the concrete durability design and service life checking provide the effective analysis under the marine environment.

Calculation of the design life of solid-rolled wheels of railway rolling stock according to the criterion of reliability

2021 ◽  
Vol 18 (1) ◽  
pp. 121-131
Author(s):  
A. A. Vorob’yev ◽  
◽  
I. V. Fedorov ◽  
E. Yu. Chistyakov ◽  
T. R. Abduganiyev ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Partial Differential Equations ◽  
Service Life ◽  
Numerical Solution ◽  
Practical Importance ◽  
Rolling Stock ◽  
Design Life ◽  
Railway Infrastructure ◽  
Railway Rolling Stock

Objective: Development of a methodology for determining the design life of solid-rolled wheels of railway rolling stock, based on the requirements of the current regulatory documentation. Methods: Methods of the theories of probability, reliability, elasticity and numerical solution of partial differential equations (finite element method) are applied. Results: A methodology for calculating the design life using the criteria of TR CU 001/2011, TR CU 002/2011 and GOST 33783–2016. Practical importance: The developed method will make it possible to exclude the presence of wheels with a significant service life on the railway infrastructure which do not provide the required level of reliability, which, in turn, can lead to sudden destruction of wheels under the cars.

Further Considerations for the Determination of Service Life for Delayed Coker Drums

2018 ◽  
Author(s):  
John J. Aumuller ◽  
Toshiya Yamamoto ◽  
Zengtao Chen
Keyword(s):  
Service Life ◽  
Mechanical Strain ◽  
Index Method ◽  
Code Construction ◽  
Design Life ◽  
Indirect Measures ◽  
Cyclic Operation ◽  
Stress Cycling ◽  
Cyclic Service

Delayed coker drums are unique in hydrocarbon processing facilities in that estimating their true design and service life has been problematic. Generally, pressure containing equipment in these facilities is designed using the notion of design life based on required pressure thickness and corrosion allowance considerations. Hence, pressure containing equipment is routinely monitored by facility inspectors for wall thickness. Although many analysts have ascribed coke drum failure to “thermal stress cycling”, the difficulty posed by the operation of coke drums results in an inability to measure or calculate the magnitude of the thermo-mechanical “stresses” and the actual number of significant exposures, that is, cycles causing fatigue damage. As well, the use of Code construction practices has been generally misapplied, for this specific equipment, as the practices are intended to define a safe design life rather than a service life. Indirect measures of service life based on shell bulge severity have fallen from favor by being ineffective. A trend to use a strain index method is somewhat more appealing but is based on static load and monotonic material property considerations rather than those properties indicative of thermal cyclic operation. Recent work has shown that thermo-mechanical strain cycling can be characterized quantitatively and used to determine a cyclic service life for both undamaged and damaged coke drums. This paper discusses some of the engineering specifics to generate a high probability estimate of coke drum fatigue service life for a new drum, a damaged-stable drum, drums with weld overlay and for drums exhibiting incremental damage.

Ship service life extension considering ship condition and remaining design life

2021 ◽  
Vol 78 ◽  
pp. 102940
Author(s):  
Liang Liu ◽  
David Y. Yang ◽  
Dan M. Frangopol
Keyword(s):  
Service Life ◽  
Life Extension ◽  
Design Life ◽  
Service Life Extension

Risk-based corrosion assessment and refurbishment of marine structures

2018 ◽  
Vol 58 (1) ◽  
pp. 60
Author(s):  
Stephan Dickinson ◽  
Kerryn Wilson ◽  
Ali Sarandily ◽  
René van der Werf ◽  
Steve Sheen ◽  
...  
Keyword(s):  
Service Life ◽  
Phase 1 ◽  
Phase 2 ◽  
Remaining Life ◽  
Liquefied Petroleum Gas ◽  
Original Design ◽  
Marine Structures ◽  
Corrosion Rates ◽  
Design Life ◽  
Inspection Techniques

This paper outlines a holistic, risk-based approach to managing the service life of existing liquefied natural gas (LNG) and liquefied petroleum gas (LPG) marine structures in Western Australia. The structures have been in service since 1989 (LNG) and 1995 (LPG) and are nearing the end of their original design life. The objective of this approach is to extend the design life for an additional 20 years to 2040. The risk-based assessment (RBA) process is composed of three main steps undertaken in sequence to identify and quantify refurbishment requirements for the timeframe. A two-campaign approach was considered, the first being in 2019 (Phase 1) and the second in 2030 (Phase 2). The RBA process combines innovative and conventional inspection techniques with a detailed desktop structural assessment of the remaining life of the structures’ individual components to enable an informed decision to be made on the refurbishment requirements for each campaign. The results of the stepped RBA process demonstrate the effectiveness of the approach to define and manage a refurbishment program that achieves the required extended service life of the structures to 2040. The RBA process enabled the first campaign’s scope to be minimised through detailed analysis and calculation of residual design life of each critical member, deferring most of the refurbishment scope to the second campaign in 2030. The study has recommended implementation of a corrosion rate trial to verify the assumed corrosion rates for the jetty structures. Environmental monitoring stations and test coupons installed on the jetty for a five-year period will confirm the actual deterioration rates specific to the jetty structures. Confirmation of actual deterioration rates may reduce uncertainty in the values over those currently assumed in the study and positively affect the identified Phase 2 refurbishment scope.

scholarly journals A DESIGN LIFE BASED APPROACH TO MULTI-HAZARD RISK ANALYSIS

2018 ◽  
pp. 81
Author(s):  
Adam S. Keen ◽  
Patrick J. Lynett
Keyword(s):  
Service Life ◽  
Cumulative Effect ◽  
Damage State ◽  
Design Life ◽  
Important Concern ◽  
Different Types ◽  
Tsunami Risk ◽  
Small Craft ◽  
Wind Events ◽  
Total Damage

Small craft harbors are important facets to many coastal communities providing a transition from land to ocean. Because of the damage resulting from the 2010 Chile and 2011 Japanese tele-tsunamis, the tsunami risk to the small craft harbors in California has become an important concern. However, tsunamis represent only one of many hazards a harbor is likely to see in California. Other natural hazards including wave attack, wind events, storm surge and sea level rise all can damage a harbor but are not typically addressed collectively in traditional risk studies. Existing approaches to assess small craft harbor vulnerably typically look at single events assigning likely damage levels to each event. However, a harbor will likely experience damage from several different types of hazards over its service life with each event contributing proportionally to the total damage state. The approach presented here will consider the how the damage from many different natural phenomena is likely to be distributed during a harbors service life and how the cumulative effect of the events could contribute to failure potential of components within the harbor.

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