scholarly journals Prospects for Advanced Engineering Design Based on Risk Assessment

10.14311/244 ◽  
2001 ◽  
Vol 41 (4-5) ◽  
Author(s):  
M. Holický
Keyword(s):  
Risk Assessment ◽  
Engineering Design ◽  
Probabilistic Approach ◽  
Design Procedure ◽  
Probability Of Failure ◽  
Probabilistic Design ◽  
Target Probability ◽  
Acceptable Risks ◽  
Near Future ◽  
Causes Of Failure

Current approaches to the design of structures are based on the concept of target probability of failure. This value is, however, often specified on the basis of comparative studies and past experience only. Moreover, the traditional probabilistic approach cannot properly consider gross errors and accidental situations, both of which are becoming more frequent causes of failure. This paper shows that it is useful to supplement a probabilistic design procedure by a risk analysis and assessment, which can take into account the consequences of all unfavourable events. It is anticipated that in the near future advanced engineering design will include criteria of acceptable risks in addition to the traditional probabilistic conditions.

scholarly journals Risk Assessment in Advanced Engineering Design

10.14311/432 ◽  
2003 ◽  
Vol 43 (3) ◽  
Author(s):  
M. Holický
Keyword(s):  
Engineering Design ◽  
Probability Of Failure ◽  
Extreme Conditions ◽  
Probabilistic Design ◽  
Engineering Systems ◽  
Engineering Structures ◽  
Design Procedures ◽  
Target Probability ◽  
Acceptable Risks ◽  
Fundamental Quantity

Traditional methods for designing of civil engineering structures and other engineering systems are frequently based on the concept of target probability of failure. However, this fundamental quantity is usually specified on the basis of comparative studies and past experience only. Moreover, probabilistic design methods suffer from several deficiencies, including lack of consideration for accidental and other hazard situations and their consequences. Both of these extreme conditions are more and more frequently becoming causes of serious failures and other adverse events. Available experience clearly indicates that probabilistic design procedures may be efficiently supplemented by a risk analysis and assessment, which can take into account various consequences of unfavourable events. It is therefore anticipated that in addition to traditional probabilistic concepts the methods of advanced engineering design will also commonly include criteria for acceptable risks.

Reliability Based Pressure Containment Uprating

2013 ◽  
Author(s):  
Elie Dib ◽  
Sherif El-Gebaly ◽  
Frank Drennan
Keyword(s):  
Structural Reliability ◽  
Probabilistic Approach ◽  
Probability Of Failure ◽  
Operating Conditions ◽  
Current Status ◽  
Pipeline System ◽  
Design Life ◽  
Target Probability ◽  
Fit For Purpose ◽  
The Cost

Over the design life of long tiebacks, project requirements may change in order to accommodate new prospects. These new prospects may have design conditions exceeding those used for the rest of the field and the existing facilities may not be able to withstand the potential increases in pressure arising from new wells. For smaller and accidental increases, the existing system may be proven to be fit for purpose by using a probabilistic approach, or a structural reliability assessment. This approach may eventually reduce the cost of the new prospect by, for example, removing the need for an over-pressure protection system, or removing the need for a dedicated pipeline system. This paper investigates the potential increase in pressure capacity of a main pipeline for an accidental over-pressure condition using a structural reliability analysis and probabilistic approach using as-built data gathered from several projects. The variations on the as-built pipeline properties, the current status of the existing pipeline, and the corresponding operating conditions are taken into account using a Monte Carlo simulation. The results present a burst pressure with an indication of a safety factor and associated with a probability of failure. A comparison between the final results and the pipeline codes target probability of failure is also performed and presented as part of this paper.

Risk assessment of white phosphorus in military training areas, a probabilistic approach

2006 ◽  
Vol 164 ◽  
pp. S139-S140 ◽  
Author(s):  
Øyvind Albert Voie ◽  
Kjetil S. Longva ◽  
Arnljot E. Strømseng ◽  
Arnt Johnsen
Keyword(s):  
Risk Assessment ◽  
Military Training ◽  
Probabilistic Approach ◽  
White Phosphorus ◽  
Military Training Areas

Design Nomographs of Compression Helical Springs for Predetermined Reliability Levels

1981 ◽  
Vol 103 (2) ◽  
pp. 268-273
Author(s):  
My Dao Thien ◽  
M. Massoud
Keyword(s):  
Probabilistic Approach ◽  
Design Procedure ◽  
Axial Loading ◽  
Geometric Parameters ◽  
Computer Algorithms ◽  
Mean Values ◽  
Helical Springs ◽  
Reliability Level ◽  
Classical Design ◽  
Mission Success

This paper discusses a probabilistic approach for the design of Compression Closely Coiled Helical Springs subjected to periodic axial loading. The classical design procedure results in deterministic geometric parameters with tolerances normally chosen according to standards without due regard to their effects on the mission success as normally expressed by a reliability level. With the proposed design procedure, the engineer can specify nominal mean values for the geometric parameters and their tolerances according to a predetermined reliability level. Design nomographs are presented to help the engineer, in the early stages of design, to choose between many alternatives. Computer algorithms can easily be written to verify the final or optimum design.

Calibration of reliability-based safety factors for sand boiling in excavations

2020 ◽  
Vol 57 (5) ◽  
pp. 742-753
Author(s):  
Ignatius Tommy Pratama ◽  
Chang-Yu Ou ◽  
Jianye Ching
Keyword(s):  
Factor Of Safety ◽  
Probability Of Failure ◽  
Reliability Theory ◽  
Design Codes ◽  
Test Results ◽  
Safety Factors ◽  
Target Probability ◽  
Analysis Methods ◽  
Actual Factor ◽  
The Relationship

This study calibrated the required factors of safety of five analysis methods for sand boiling using reliability theory. The factors of safety computed by the five analysis methods were compared with the results of a series of sand boiling model tests. The comparison shows that rigorous methods (Terzaghi’s and Harza’s methods) were more accurate in predicting the factors of safety compared to the simplified methods (Harr’s, simplified Terzaghi’s, and simplified Harza’s methods). The statistics of the model factor for each method, defined as the actual factor of safety divided by the computed one, was calibrated by the model test results. These statistics were then used to establish the relationship between the target probability of failure and the required factor of safety by reliability theory. Verification using a full-scale sand boiling case history shows that the required factor of safety calibrated by the reliability theory was more reasonable than the required factors of safety in references and design codes.

scholarly journals Development of a Bayesian network for probabilistic risk assessment of pesticides

2021 ◽  
Author(s):  
Sophie Mentzel ◽  
Merete Grung ◽  
Knut Erik Tollefsen ◽  
Marianne Stenrod ◽  
Karina Petersen ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Bayesian Network ◽  
Environmental Risk ◽  
Environmental Risk Assessment ◽  
Probability Distributions ◽  
Probabilistic Approach ◽  
Probabilistic Risk Assessment ◽  
Risk Calculation ◽  
Link Information ◽  
Probabilistic Risk

Conventional environmental risk assessment of chemicals is based on a calculated risk quotient, representing the ratio of exposure to effects of the chemical, in combination with assessment factors to account for uncertainty. Probabilistic risk assessment approaches can offer more transparency, by using probability distributions for exposure and/or effects to account for variability and uncertainty. In this study, a probabilistic approach using Bayesian network (BN) modelling is explored as an alternative to traditional risk calculation. BNs can serve as meta-models that link information from several sources and offer a transparent way of incorporating the required characterization of uncertainty for environmental risk assessment. To this end, a BN has been developed and parameterised for the pesticides azoxystrobin, metribuzin, and imidacloprid. We illustrate the development from deterministic (traditional) risk calculation, via intermediate versions, to fully probabilistic risk characterisation using azoxystrobin as an example. We also demonstrate seasonal risk calculation for the three pesticides.

scholarly journals Identifying preventive maintenance guideline for a combine harvester with application of failure mode and effect analysis technique

2020 ◽  
Vol 319 ◽  
pp. 01004
Author(s):  
Voraya Wattanajitsiri ◽  
Rapee Kanchana ◽  
Surat Triwanapong ◽  
Kittipong Kimapong
Keyword(s):  
Risk Assessment ◽  
Failure Mode ◽  
Preventive Maintenance ◽  
Risk Priority Number ◽  
Effect Analysis ◽  
Analysis Technique ◽  
Combine Harvester ◽  
A Chain ◽  
Near Future

The objective of this research was to study a risk assessment of the rice combine harvester using FMEA technique implementation and suggested the procedures to maintain the parts of the rice combine harvester by analyzing the causes of risk assessment of FMEA. The FMEA was also applied to specify failure causes and effects that occurred in the rice harvester. The obtained data were calculated for a risk priority number (RPN) and then sorted to be a descending order. The high RPN part was analyzed for the causes and effects and then suggested a preventive maintenance in near future. The results revealed that the highest RPN of 576 was found when a chain surface was considered and also showed the maximum risk among the considered parts in the rice combine harvester. While, the lowest RPN of 144 was found when a rice sieve part was considered but this RPN was still higher than that of 100 RPN which was required to specify the preventive maintenance.

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