Long‐term ceramic reliability analysis including the crack‐velocity threshold and the “bathtub” curve

2018 ◽  
Vol 101 (12) ◽  
pp. 5732-5744 ◽  
Author(s):  
Robert F. Cook
Keyword(s):  
Reliability Analysis ◽  
Crack Velocity ◽  
Velocity Threshold

Reliability of TLP Tendons Under Storm Sea States

2005 ◽  
Author(s):  
Federico Barranco Cicilia ◽  
Edison Castro Prates de Lima ◽  
Lui´s Volnei Sudati Sagrilo
Keyword(s):  
Reliability Analysis ◽  
Limit State ◽  
Nonlinear Dynamic Analysis ◽  
Analytical Models ◽  
Cumulative Probability ◽  
Wave Forces ◽  
Ultimate Limit State ◽  
Sea State ◽  
Extreme Response

This paper presents a methodology for reliability analysis of Tension Leg Platform (TLP) tendons subjected to extraordinary sea state conditions like hurricanes or winter storms. A coupled approach in time domain is used to carry out TLP random nonlinear dynamic analysis including wind, current and first and second order wave forces. The tendons Ultimate Limit State (ULS) condition is evaluated by an Interaction Ratio (IR) taking into account dynamic combination among tension, bending and hydrostatic pressure. Expected long-term extreme IR is obtained through the integration of cumulative probability functions (CPFs) fitted to response maxima associated to individual short term sea states. The reliability analysis is performed using a time-integrated scheme including uncertainties in loads, tendon strength, and analytical models. Failure probabilities for the most loaded tendon of a TLP in Campeche Bay, Mexico, considering a 100-yr design sea state and the 100-yr extreme response generated by long-term observed storms are compared.

scholarly journals Reliability Dynamic Analysis by Fault Trees and Binary Decision Diagrams

Information ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 324 ◽  
Author(s):  
Fausto Pedro García Márquez ◽  
Isaac Segovia Ramírez ◽  
Behnam Mohammadi-Ivatloo ◽  
Alberto Pliego Marugán
Keyword(s):  
Wind Turbine ◽  
Reliability Analysis ◽  
Binary Decision Diagrams ◽  
Computational Cost ◽  
Optimal Order ◽  
Decision Diagrams ◽  
Breadth First Search ◽  
Ranking Methods ◽  
Binary Decision

New wind turbines are becoming more complex and reliability analysis of them rising in complexity. The systems are composed of many components. Fault tree is used as an useful tool to analyze these interrelations and provide a scheme of the wind turbine, to get a quick overview of the behavior of the system under certain conditions of the components. However, it is complicated and in some cases not possible, to identify the conditions that would generate a wind turbine failure. A quantitative and qualitative reliability analysis of the wind turbine is proposed in this study. Binary decision diagrams are employed as a suitable and operational method to facilitate this analysis and to get an analytical expression by the Boolean functions. The size of the binary decision diagram, i.e., the computational cost for solving the problem, has an important dependence on the order of the components or events considered. Different heuristic ranking methods are used to find an optimal order or one closed, and to validate the results: AND, level, top-down-left-right, deep-first search and breadth-first-search. Birnbaum and criticality importance measures are proposed to evaluate the relevance of each component. This analysis leads to classify the events according to their importance with respect to the probability of the top event. This analysis provides the basis for making medium and long-term maintenance strategies.

scholarly journals Assessment of risks of loose landslide deposits formed by the 2008 Wenchuan earthquake

2012 ◽  
Vol 12 (5) ◽  
pp. 1381-1392 ◽  
Author(s):  
S. Zhang ◽  
L. M. Zhang ◽  
M. Peng ◽  
L. L. Zhang ◽  
H. F. Zhao ◽  
...  
Keyword(s):  
Reliability Analysis ◽  
Wenchuan Earthquake ◽  
Quantitative Risk Assessment ◽  
2008 Wenchuan Earthquake ◽  
The 2008 Wenchuan Earthquake ◽  
Loose Deposits ◽  
Calculated Probability ◽  
The Individual ◽  
Risk Assessment Methodology

Abstract. A Geographic Information System (GIS)-based quantitative risk assessment methodology was adopted to evaluate the risks of loose deposits formed by the 2008 Wenchuan earthquake along a highway near the epicenter. A total of 305 loose deposits with a total volume of 4.0 × 107 m3 has been identified. A physical model was used to determine the failure probability of these loose deposits under six rainfall scenarios, assuming the loose deposits as infinite slopes. The calculated probability of rain-induced slope failures is verified by the recorded landslides at the same site during a storm in 2010. Seventy-nine out of the 112 rain-induced loose deposit failures are predicted by the reliability analysis, with an accuracy of 71%. The results of reliability analysis and information on the consequence of these rain-induced landslides enable the estimation of the annual societal and individual risks of the loose deposits. Under the rainfall scenarios of 30 mm/12 h and 70 mm/12 h, the estimated annual societal risks reach 8.8 and 7.5, respectively, and the individual risks reach 0.05 and 0.04, respectively, which are very high compared with present risk acceptance criteria. The preliminary assessment provides a benchmark for studying the long-term risks of these loose deposits and engineering decision.

Sign in / Sign up

Export Citation Format

Share Document