Computational Structural Reliability Analysis of a Turbine Blade

1993 ◽  
Author(s):  
H. R. Millwater ◽  
Y.-T. Wu
Keyword(s):  
Reliability Analysis ◽  
Turbine Blade ◽  
System Reliability ◽  
Structural Reliability ◽  
Failure Modes ◽  
Component Reliability ◽  
Importance Sampling Method ◽  
Creep Stress ◽  
Analysis Methodology ◽  
Computational Implementation

A system reliability methodology has recently been developed to determine accurately and efficiently the reliability of structures with multiple failure modes. This paper explores the computational implementation and application of the methodology through the structural system reliability calculation of a turbine blade subject to randomness in material properties. Failure due to creep, stress overload, and vibration is considered. The methodology consists of a probabilistic system reliability analysis methodology integrated with finite element methods. The failure paths and failure modes are organized using a fault tree. An efficient method for assessing the reliability of a single failure mode, i.e., component reliability, is implemented as well as an efficient adaptive importance sampling method to assess the system reliability. A probabilistic structural analysis program, NESSUS, is used for the calculations.

Reliability Analysis of Uncertain Nonlinear System Subject to Correlated Failure

2008 ◽  
Vol 44-46 ◽  
pp. 515-522
Author(s):  
X.F. Zhang ◽  
Yi Min Zhang ◽  
Xian Zhen Huang
Keyword(s):  
Reliability Analysis ◽  
System Reliability ◽  
Failure Modes ◽  
Fourth Moment ◽  
Strongly Correlated ◽  
Hysteretic Model ◽  
Analysis Method ◽  
Random Parameters ◽  
Uncertain Nonlinear System ◽  
Probability Information

On the basis of the Bouc-Wen hysteretic model, a numerical method for the reliability analysis of stochastic multi-degree-of-freedom hysteretic system with correlated failure modes is presented. Under the first passage model, considering the random caused by hysteretic loop itself, the theory of incomplete probability information and the fourth-moment technique and Gram Charlier series are employed to develop a numerical reliability analysis method systematically. The numerical example reveals that in most of cases, though system is characterized by a set of independent random parameters, the responses are strongly correlated, and correlation coefficient between the responses is fluctuated with time. The system reliability with correlated failure modes is evaluated with proposed method, and the result obtained by this method is compared well with the Monte-Carlo simulations.

Reliability Model for Complex Mechanical Component Design

2013 ◽  
Vol 365-366 ◽  
pp. 28-31
Author(s):  
Li Yang Xie ◽  
Wen Xue Qian ◽  
Ning Xiang Wu
Keyword(s):  
System Reliability ◽  
Failure Modes ◽  
Statistical Dependence ◽  
Series System ◽  
Reliability Model ◽  
Component Reliability ◽  
Damage Site ◽  
Mechanical Component ◽  
Component Design ◽  
Element Failure

Taking into account the uncertainty in material property and component quality, a complex mechanical component such as a gear should be treated as a series system instead of a component when evaluating its reliability, since there exist many sites of equal likelihood to fail. Besides, conventional system reliability model is not applicable to such a system because of the statistical dependence among the failures of the every element (damage site). The present paper presents a model to estimate complex mechanical component reliability by incorporating order statistic of element strength into load-strength interference analysis, which can deal with multiple failure mechanisms, reflect statistical dependence among element failure events and that among different failure modes.

Structural Reliability Analysis Method for Assessing the Fatigue Capacity of Subsea Wellhead Connectors

2020 ◽  
Author(s):  
Torfinn Hørte ◽  
Lorents Reinås ◽  
Anders Wormsen ◽  
Andreas Aardal ◽  
Per Gustafsson
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Failure Modes ◽  
Fatigue Loading ◽  
Load Effect ◽  
Structural Reliability Analysis ◽  
Structural Capacity ◽  
Drilling Operations ◽  
Male Part ◽  
External Loads

Abstract Subsea Wellheads are the male part of an 18 3/4” bore connector used for connecting subsea components such as drilling BOP, XT or Workover systems equipped with a female counterpart — a wellhead connector. Subsea wellheads have an external locking profile for engaging a preloaded wellhead connector with matching internal profile. As such connection is made subsea, a metal-to-metal sealing is obtained, and a structural conduit is formed. The details of the subsea wellhead profile are specified by the wellhead user and the standardized H4 hub has a widespread use. In terms of well integrity, the wellhead connector is a barrier element during both well construction (drilling) activities and life of field (production). Due to the nature of subsea drilling operations, a wellhead connector will be subjected to external loads. Fatigue and plastic collapse due to overload are therefore two potential failure modes. These two failure modes are due to the cyclic nature of the loads and the potential for accidental and extreme single loads respectively. The safe load the wellhead connector can sustain without failure can be established by deterministic structural capacity methods. This paper outlines how a generic and probabilistic engineering method; Structural Reliability Analysis, can be applied to a subsea wellhead connector to estimate the probability of fatigue failure (PoF). As the wellhead connector is a mechanism consisting of a plurality of parts the load effect from cyclic external loads is influenced by uncertainty in friction, geometry and pre-load. Further, there is a inter dependence between these parameters that complicates the problem. In addition to these uncertainties, uncertainties in the fatigue loading itself (from rig and riser) is also accounted for. This paper presents results from applications of Structural Reliability Analysis (SRA) to a wellhead connector and provides experiences and learnings from this case work.

An adaptive directional importance sampling method for structural reliability analysis

2018 ◽  
Vol 70 ◽  
pp. 14-20 ◽  
Author(s):  
Mohsen Ali Shayanfar ◽  
Mohammad Ali Barkhordari ◽  
Moien Barkhori ◽  
Mohammad Barkhori
Keyword(s):  
Reliability Analysis ◽  
Importance Sampling ◽  
Structural Reliability ◽  
Sampling Method ◽  
Structural Reliability Analysis ◽  
Importance Sampling Method
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