Risk Based Acceptance Criteria for Joints Subject to Fatigue Deterioration

2004 ◽  
Vol 127 (2) ◽  
pp. 150-157 ◽  
Author(s):  
Daniel Straub ◽  
Michael Havbro Faber
Keyword(s):  
Fatigue Failure ◽  
System Reliability ◽  
Failure Modes ◽  
Optimal Allocation ◽  
Influence Factor ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Revealed Preferences ◽  
Acceptance Criteria ◽  
The Individual

Different approaches to determine the acceptance criteria for fatigue induced failure of structural systems and components are discussed and compared. The considered approaches take basis in either optimization (societal cost-benefit analysis) or are derived from past and actual practice or codes (revealed preferences). The system acceptance criteria are expressed in terms of the maximal acceptable annual probability of collapse due to fatigue failure. Acceptance criteria for the individual fatigue failure modes are then derived using a simplified system reliability model. The consequence of fatigue failure of the individual joints is related to the overall system by evaluating the change in system reliability given fatigue failure. This is facilitated by the use of a simple indicator, the Residual Influence Factor. The acceptance criteria is thus formulated as a function of the system redundancy and complexity. In addition, the effect of dependencies in the structure on the acceptance criteria are investigated. Finally an example is presented where the optimal allocation of the risk to different welded joints in a jacket structure is performed by consideration of the necessary maintenance efforts.

Risk Based Acceptance Criteria for Joints Subject to Fatigue Deterioration

2003 ◽  
Author(s):  
Daniel Straub ◽  
Michael Havbro Faber
Keyword(s):  
Fatigue Failure ◽  
System Reliability ◽  
Failure Modes ◽  
Optimal Allocation ◽  
Influence Factor ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Revealed Preferences ◽  
Acceptance Criteria ◽  
The Individual

Different approaches to determine the acceptance criteria for fatigue induced failure of structural systems and components are discussed and compared. The considered approaches take basis in either optimization (societal cost-benefit analysis) or are derived from past and actual practice or codes (revealed preferences). The system acceptance criteria are expressed in terms of the maximal acceptable annual probability of collapse due to fatigue failure. Acceptance criteria for the individual fatigue failure modes are then derived using a simplified system reliability model. The consequence of fatigue failure of the individual joints is related to the overall system by evaluating the change in system reliability given fatigue failure. This is facilitated by the use of a simple indicator, the Residual Influence Factor. The acceptance criteria is thus formulated as a function of the system redundancy and complexity. In addition, the effect of dependencies in the structure on the acceptance criteria are investigated. Finally an example is presented where the optimal allocation of the risk to different welded joints in a jacket structure is performed by consideration of the necessary maintenance efforts.

scholarly journals International Technical Standards: An Overview

2002 ◽  
Author(s):  
Robert Hebner
Keyword(s):  
Hybrid System ◽  
Economic Benefit ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
International Standards ◽  
Benefit Analysis ◽  
Technical Standards ◽  
Global Standards ◽  
The Individual ◽  
The Cost

The growing globalization of industry is stimulating a growing emphasis on international standards. Standards are important because they provide significant economic benefit. They are also costly and much of the benefit is broad-based, i.e. it does not accrue preferentially to those who incur the cost. Finally, there is a highly disaggregated international standards system and at least two very different basic philosophies as to how standard systems should operate. The effect of the individual cost-benefit analysis by organizations may produce a hybrid system that produces both global standards in which each country participates in the development as well as less costly technical and consortium standards.

The Heroin Problem: Policy Alternatives in Dealing with Heroin Use

1974 ◽  
Vol 4 (1) ◽  
pp. 69-91 ◽  
Author(s):  
Robert E. Marks
Keyword(s):  
Methadone Maintenance ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Detailed Comparison ◽  
Therapeutic Communities ◽  
Heroin Use ◽  
Policy Alternatives ◽  
The Social ◽  
The Individual ◽  
Heroin Maintenance

The paper examines the social and private aspects of heroin use in the U.S. today and attempts to estimate the associated costs, both society's and the individual user's. Possible goals of any government policy are discussed. Twelve possible policy alternatives are examined, eight dealing with the demand for heroin, and four dealing with its supply. These alternatives are compared using a rough cost-benefit analysis in terms of costs and benefits to society at large. A more detailed comparison is made of therapeutic communities, methadone maintenance, and the British experience of prescription heroin maintenance as alternatives. The conclusion is reached that to minimize social cost while containing the spread of heroin usage a scheme of prescription heroin should be implemented; but if the spread of usage is seen as benign, the best policy is to sell the drug freely to any adult as alcohol is today.

Presurgical Routine Screening

PEDIATRICS ◽  
1992 ◽  
Vol 90 (5) ◽  
pp. 780-780
Author(s):  
ALAN COHEN ◽  
CAROL BURK
Keyword(s):  
Additional Data ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Routine Screening ◽  
Screening Tests ◽  
Coagulation Disorders ◽  
Benefit Analysis ◽  
Appropriate Use ◽  
Laboratory Screening ◽  
The Individual

In Reply.— Doctors Lackmann and Töllner provide additional data supporting our finding that the discovery of clinically important coagulation disorders during routine preoperative laboratory screening is infrequent. However, these investigators are troubled, as are we, by the problem of determining the appropriate use of screening tests when the disorder is rare and the tests are imperfect, but the consequence of failing to recognize the disorder may be grave. Even the most elaborate cost-benefit analysis may be of little comfort in approaching the individual patient and concerned parents.

Wellbeing Cost-effectiveness Analysis and Existing Approaches

2021 ◽  
pp. 279-332
Author(s):  
Paul Frijters ◽  
Christian Krekel
Keyword(s):  
Cost Effectiveness ◽  
Current Practice ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Business Case ◽  
Cost Effectiveness Analysis ◽  
Important Distinction ◽  
Effectiveness Analysis ◽  
Public Resource ◽  
The Individual

The fourth chapter is targeted mainly at readers who wish to quantify how much benefits and costs are generated by future or existing policies and programmes. The chapter compares the authors’ basic methodology for wellbeing cost-effectiveness analysis (CEA) with existing approaches to decide on public resource allocations. The main comparison is with cost-benefit analysis (CBA), but they also compare it with multi-criterion approaches, social rates of return analyses, and business case scenarios or impact assessments. The authors start with a quick reminder of their basic methodology for wellbeing CEA, after which they sketch the current practice of CBA, highlighting the differences in a stylized, non-technical manner. They also sketch the relationship between WELLBYs (wellbeing years) and QALYs (quality-adjusted life-years), deriving a proper translation between the two measures, which will culminate in the important distinction between the individual willingness-to-pay for a WELLBY and the social costs of producing a WELLBY. They then answer some crucial questions as to how more wellbeing knowledge can be incorporated into existing approaches, including the question of the monetization of wellbeing effects for current-practice CBA. Apart from analysts, this chapter is also of interest to academics in the fields of health and wellbeing as it discusses in depth the differences between WELLBYs and QALYs. The discussion on wellbeing approaches from around the world is of importance to all those tasked with embedding wellbeing into their own country’s public-sector systems.

The Concept of Cost in the Economic Evaluation of Health Care: A Theoretical Inquiry

1994 ◽  
Vol 10 (4) ◽  
pp. 675-682 ◽  
Author(s):  
Magnus Johannesson
Keyword(s):  
Health Care ◽  
Economic Evaluation ◽  
Willingness To Pay ◽  
Treatment Program ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Economic Evaluations ◽  
Benefit Analysis ◽  
Full Economic Evaluation ◽  
The Individual

AbstractThe costs included in economic evaluations of health care vary from study to study. Based on the theory of cost-benefit analysis, the costs that should be included in an economic evaluation are those not already included in the measurement of willingness to pay (net willingness to pay above any treatment costs paid by the individual) in a cost-benefit analysis or in the easurement of effectiveness in a cost-effectiveness analysis. These costs can be defined as the onsumption externality of the treatment (the change in production minus consumption for those included in the treatment program). For a full economic evaluation, the consequences for those included in the treatment program and a caring externality (altruism) should also be added.

scholarly journals A fracture mechanics framework for optimising design and inspection of offshore Wind Turbine support structures against fatigue failure

2020 ◽  
Author(s):  
Peyman Amirafshari ◽  
Feargal Brenan ◽  
Athanasios Kolios
Keyword(s):  
Fracture Mechanics ◽  
Wind Turbine ◽  
Fatigue Failure ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Support Structures ◽  
Benefit Analysis ◽  
Support Structure

Abstract. Offshore Wind Turbine (OWT) support structures need to be designed against fatigue failure under cyclic aerodynamic and wave loading. The fatigue failure can be accelerated in a corrosive sea environment. Traditionally, a stress-life approach called the S-N curve method has been used for design of structures against fatigue failure. There are a number of limitations in S-N approach related to welded structures which can be addressed by the fracture mechanics approach. In this paper the limitations of the S-N approach related to OWT support structure are addressed, a fatigue design framework based on fracture mechanics is developed. The application of the framework to a monopile OWT support structure is demonstrated and optimisation of in-service inspection of the structure is studied. It was found that both the design of the weld joint and Non-destructive testing techniques can be optimised to reduce In-service frequency. Furthermore, probabilistic fracture mechanics as a form of risk-based design is outlined and its application to the monopile support structure is studied. The probabilistic model showed to possess a better capability to account for NDT reliability over a range of possible crack sizes as well as providing a risk associated with the chosen inspection time which can be used in inspection cost benefit analysis. There are a number of areas for future research. including better estimate of fatigue stress with a time-history analysis, the application of framework to other types of support structures such as Jackets and Tripods, and integration of risk-based optimisation with a cost benefit analysis.

Subsea Spare Parts Analysis Optimisation

2019 ◽  
Author(s):  
Tiarnan Coffey ◽  
Christopher Rai ◽  
John Greene ◽  
Stephen O’Brien Bromley
Keyword(s):  
Sensitivity Analysis ◽  
Failure Modes ◽  
Cost Benefit Analysis ◽  
Block Diagram ◽  
Cost Benefit ◽  
Spare Parts ◽  
Quantitative Methodology ◽  
Analysis Software ◽  
Monte Carlo Simulation Technique ◽  
Ram Analysis

Abstract The main objective of this paper is to present a fully quantitative methodology combining reliability, availability and maintainability (RAM) analysis and cost-benefit analysis (CBA) approaches to determine the optimum sparing strategy for subsea components considering reliability data, lead times, availability and cost. This methodology can be utilized at any stage of an asset lifecycle, from design to operation and can be adjusted to reflect modifications throughout the life of field. Using commercially available RAM analysis software, Maros [2], a reliability block diagram (RBD) is constructed to represent the reliability structure and logic of the system being analyzed. Retrievable components, for which spares would be suitable, are then identified within the model to review and update the failure modes and reliability information for each component. Reliability information can be based on project specific data or from industry-wide sources such as OREDA. The RAM analysis software uses the Monte-Carlo simulation technique to determine availability. A sensitivity analysis is then performed to determine maximum availability while holding the minimum required stock level of spare components. A sparing priority factor (SPF) analysis is then performed in addition to the RAM sensitivity analysis to support those results and consider spare purchase, storage and preservation costs. The SPF gives a weighting to the storage cost against the potential impact on production. The SPF is a number used to determine a component’s need to have a spare. A high SPF indicates an increased requirement to hold a spare.

scholarly journals Youth unemployment and crime: an empirical investigation for Turkey

2020 ◽  
Vol 20 (1) ◽  
pp. 27
Author(s):  
Halil Tunca ◽  
Ferda Esin Gulel
Keyword(s):  
Unemployment Rate ◽  
Spatial Econometrics ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Property Crime ◽  
Youth Unemployment ◽  
Crime Rates ◽  
Regional Cluster ◽  
Unemployment And Crime ◽  
The Individual

The crime economy has lately become a popular field of research because of regular increases in crime rates. Economists’ interest in crime analysis goes back to Becker’s (1968) model. “Cost‑benefit” analysis determined the crime preferences of rational individuals in this model. According to this analysis, if the benefit from the crime is higher than the cost to be faced, the individual will be willing to commit the crime. One of the factors studied in the crime phenomenon is migration. The main reason for migration is unemployment and poverty. The main purpose of this study is to determine the relationship between youth unemployment and crime rates by migration-receiving regions. By this purpose, aggregated crime rates, as well as non-aggregated crime rates (property crime, theft, and violent crime), were used. Also, the youth unemployment rate has been subdivided by gender differences and educational levels. We prefer to use spatial econometrics models in this study because of the unemployment rate, and crime rate showing the regional cluster pattern. Migration-receiving is considered as regions neighboring.

scholarly journals Responsive Governance and Harmful Microbial Blooms on Lake Erie: An ABM Approach

2019 ◽  
Vol 5 (1) ◽  
pp. 24
Author(s):  
DG Webster ◽  
Tyler Pavlovich
Keyword(s):  
Lake Erie ◽  
Oil Spills ◽  
Complex Dynamics ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Distinct Region ◽  
Individual Level ◽  
Action Threshold ◽  
The Individual ◽  
Model Features

In general, decision makers tend to respond to problems rather than prevent them. In political science, this process of responsive governance is associated with complex dynamics such as availability cascades and punctuated equilibrium. However, most authors treat problems as one-time events, like oil spills or political scandals. Here, we use an agent based model loosely based on the Lake Erie watershed to explore how responsive governance evolves along with an on-going but noisy environmental problem: harmful microbial blooms. This conceptual model features a two-level decision process based on Jones and Baumgartner (2005). Meta-agents representing the individual level of analysis “perceive” blooms either directly via observation if they are near a bloom or indirectly through the media. As a meta-agent observes more blooms, their concern increases until it crosses an action threshold, at which point they use simple cost-benefit analysis to select from a range of options. One of these options is to send a signal to their policy agent, which aggregates these political signals based on a range of assumptions and then decides on actions in much the same way as the metapopulations themselves. We examine two major scenarios, one in which there is a single policy maker managing the entire region (e.g. the national government) and one where there are 5 policy makers, each separately regulating a demographically and geographically distinct region. Although the model is relatively simple, it lets us explore how variability in risk perception and responsive governance shape the functioning of the entire coupled human and natural system, including biophysical feedbacks.

Sign in / Sign up

Export Citation Format

Share Document