A new probabilistic approach for reliability assessment for urban networks

2001 ◽  
Author(s):  
R.R. Austria ◽  
Xiaokang Xu ◽  
M.E.N. du Preez ◽  
D.J. Vrey
Keyword(s):  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Urban Networks

Simplified Strength Reliability and Integrity Analysis of TTRs

2014 ◽  
Author(s):  
Mir Emad Mousavi ◽  
Sanjeev Upadhye ◽  
Kevin Haverty
Keyword(s):  
Extreme Events ◽  
Structural Reliability ◽  
Probability Distributions ◽  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Cost Effective ◽  
Probability Of Failure ◽  
Annual Probability ◽  
Reliability Methods ◽  
Integrity Analysis

The design of riser systems can be improved if structural reliability methods are used to assess their safety and integrity and confirm that such design meets a target annual probability of failure. TTRs are typically multi–bore assemblies involving several sub-assemblies. The failure of any of the components of a TTR under extreme or service environmental conditions can lead to an immediate failure of the entire assembly and impose a direct risk of damaging the wellheads, conductors, casing and tubing hangers, or other subsea equipment, because they are installed directly on top of the wellhead. However, the actual strength safety of the TTR cannot be examined unless after it is installed and examined under extreme events. Because of the numerous uncertainties associated with the design of TTRs, a probabilistic approach based on structural reliability methods can account for many of those uncertainties and serve as a basis for their reliable and cost-effective design. In turn, a comprehensive reliability assessment of a TTR requires extensive analysis that is considerably more complex and time consuming compared to a conventional deterministic-based analysis. This paper presents a probabilistic-based simplified methodology for the strength reliability assessment of TTR systems. In this method, marginal values on some uncertain model inputs are considered similar to the conventional analysis methods but, some key random variables related to environmental demands and component capacities are considered with their associated probability distributions. As a result, this method can be used to estimate the minimum level of safety of the TTR under extreme events. Additionally, results of the proposed method are discussed for integrity analysis and integrity-based optimal design of the TTR system, which compare the safety of the TTR components and estimate the component Optimality Factors for improving the design integrity and meeting a target minimum annual probability of failure.

scholarly journals Fatigue damage and reliability assessment of subway train bogie frames under operating conditions

2020 ◽  
Vol 12 (1) ◽  
pp. 168781402090359
Author(s):  
Binjie Wang ◽  
Shouguang Sun ◽  
Shuang Ma ◽  
Xi Wang
Keyword(s):  
Fatigue Damage ◽  
Fatigue Cracks ◽  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Elastic Vibration ◽  
Assessment Method ◽  
Operating Conditions ◽  
Fatigue Reliability ◽  
Rail Corrugation ◽  
Subway Train

Fatigue cracks developed on subway train bogie frames before reaching the designed lifetime, which poses great challenges to operational safety. This article presents a structural fatigue reliability assessment method combining both the in-service measurement of dynamic stress and probabilistic approach for lifetime prediction. It was found that curved interval with rail corrugation can induce the elastic vibration and the modal stress on the frame, which caused the accelerated accumulation of the fatigue damage. The predicted failure mileage for the welding joint with 99% reliability was only 340,000 km, which agreed well with the real operation situation.

scholarly journals A Fuzzy Approach for the Kinematic Reliability Assessment of Robotic Manipulators

Robotica ◽  
2021 ◽  
pp. 1-15
Author(s):  
Fabian A. Lara-Molina ◽  
Didier Dumur
Keyword(s):  
Fuzzy Theory ◽  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Robotic Manipulators ◽  
Fuzzy Reliability ◽  
End Effector ◽  
Positioning Errors ◽  
Novel Method ◽  
Joint Clearances ◽  
Failure Possibility

SUMMARY This paper aims at developing a novel method to assess the kinematic reliability of robotic manipulators based on the fuzzy theory. The kinematic reliability quantifies the probability of obtaining positioning errors within acceptable limits. For this purpose, the fuzzy reliability evaluates the effect of the joint clearances on the end-effector position to compute a failure possibility index. As an alternative to the conventional methods reported in the literature, this failure possibility index conveys a novel assessment of the kinematic performance. The numerical results are compared with the well-known probabilistic approach based on the Monte Carlo simulation.

scholarly journals Numerical solution of hard rock disintegration process – part 2

2012 ◽  
Vol 58 (3) ◽  
pp. 39-46
Author(s):  
Karel Frydrýšek
Keyword(s):  
Monte Carlo ◽  
Hard Rock ◽  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Assessment Method ◽  
Deterministic Approach ◽  
Disintegration Process ◽  
Stochastic Inputs ◽  
Simulation Based ◽  
Rock Disintegration

Abstract This paper focuses on a numerical analysis of a hard rock (ore) disintegration process. A bit moves into the ore and subsequently disintegrates it. The disintegration (i.e. fracture of ore) is solved via a deterministic approach (FEM) and a probabilistic approach (FEM in combination with the SBRA - Simulation-Based Reliability Assessment method, i.e. Monte Carlo simulations, stochastic inputs). The ore is disintegrated by deactivating the finite elements satisfying fracture conditions. The results are compared with experiments. The application of the SBRA method is a new and innovative trend in this area. Finally, the probabilistic reliability assessment is mentioned.

Enhanced probabilistic approach for substation reliability assessment

2019 ◽  
Vol 13 (12) ◽  
pp. 2488-2495 ◽  
Author(s):  
Bagen Bagen ◽  
Dange Huang ◽  
Karim Fattal
Keyword(s):  
Probabilistic Approach ◽  
Reliability Assessment

scholarly journals Reliability Assessment of Existing Structures

2008 ◽  
Vol 4 (1) ◽  
pp. 149-164
Author(s):  
Marková Jana
Keyword(s):  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Probabilistic Methods ◽  
International Standard ◽  
Existing Structures

Reliability Assessment of Existing Structures The international standard ISO 13822 provides procedures for the reliability assessment of existing structures including the application of probabilistic methods. Probabilistic approach facilitates to decide about new exploitation of existing structures. Application of probabilistic methods for the reliability assessment of existing structures is shown on the example of deteriorated balcony beams.

Reliability Assessment of Fatigue Critical Welded Details in Wind Turbine Jacket Support Structures

2013 ◽  
Author(s):  
Kim Branner ◽  
Henrik Stensgaard Toft ◽  
Philipp Haselbach ◽  
Anand Natarajan ◽  
John D. Sørensen
Keyword(s):  
Structural Dynamics ◽  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Offshore Wind ◽  
Support Structures ◽  
Support Structure ◽  
Operational Conditions ◽  
Offshore Wind Turbines ◽  
Stress Cycles ◽  
The Individual

This paper describes a probabilistic approach to reliability assessment of fatigue critical welded details in jacket support structures for offshore wind turbines. The analysis of the jacket response to the operational loads is performed using Finite Element Method (FEM) simulations in SIMULIA Abaqus. Fatigue stress cycles are computed on the jacket members by applying tower top loads from an aeroelastic simulation with superimposed marine loads and in accordance to the IEC-61400-3 guidelines for operational conditions. The combined effect of the hydrodynamic loads and the rotor loads on the jacket structure is analyzed in a de-coupled scheme, but including the structural dynamics of the support structure. The failure prediction of the welded joints, connecting the individual members of the support structure is based on SN-curves and Miners rule according to ISO 19902 and DNV-RP-C203/DNV-OS-J101. Probabilistic SN-curves and a stochastic model for Miners rule is used to estimate the reliability of selected critical welded details in the jacket structure taken into account the uncertainty in the fatigue stresses.

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