Reliability analysis of corroded pipelines: Novel adaptive conjugate first order reliability method

2019 ◽  
Vol 62 ◽  
pp. 103986 ◽  
Author(s):  
Behrooz Keshtegar ◽  
Mohamed El Amine Ben Seghier ◽  
Shun-Peng Zhu ◽  
Rouzbeh Abbassi ◽  
Nguyen-Thoi Trung
Keyword(s):  
Reliability Analysis ◽  
First Order Reliability Method ◽  
First Order ◽  
Reliability Method

scholarly journals A decoupling algorithm with first-order asymptotic integration for reliability-based design optimization

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879333 ◽  
Author(s):  
Zhiliang Huang ◽  
Tongguang Yang ◽  
Fangyi Li
Keyword(s):  
Design Optimization ◽  
Reliability Analysis ◽  
Optimization Problems ◽  
Asymptotic Integration ◽  
Probabilistic Constraints ◽  
Reliability Based Design Optimization ◽  
First Order Reliability Method ◽  
First Order ◽  
Reliability Based Design ◽  
Reliability Method

Conventional decoupling approaches usually employ first-order reliability method to deal with probabilistic constraints in a reliability-based design optimization problem. In first-order reliability method, constraint functions are transformed into a standard normal space. Extra non-linearity introduced by the non-normal-to-normal transformation may increase the error in reliability analysis and then result in the reliability-based design optimization analysis with insufficient accuracy. In this article, a decoupling approach is proposed to provide an alternative tool for the reliability-based design optimization problems. To improve accuracy, the reliability analysis is performed by first-order asymptotic integration method without any extra non-linearity transformation. To achieve high efficiency, an approximate technique of reliability analysis is given to avoid calculating time-consuming performance function. Two numerical examples and an application of practical laptop structural design are presented to validate the effectiveness of the proposed approach.

First-Order Reliability Method for Structural Reliability Analysis in the Presence of Random and Interval Variables

2015 ◽  
Vol 1 (4) ◽  
Author(s):  
Umberto Alibrandi ◽  
C. G. Koh
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Limit State ◽  
Computational Cost ◽  
Computational Effort ◽  
Stochastic Dynamic ◽  
First Order Reliability Method ◽  
First Order ◽  
Structural Reliability Analysis ◽  
Reliability Method

This paper presents a novel procedure based on first-order reliability method (FORM) for structural reliability analysis in the presence of random parameters and interval uncertain parameters. In the proposed formulation, the hybrid problem is reduced to standard reliability problems, where the limit state functions are defined only in terms of the random variables. Monte Carlo simulation (MCS) for hybrid reliability analysis (HRA) is presented, and it is shown that it requires a tremendous computational effort; FORM for HRA is more efficient but still demanding. The computational cost is significantly reduced through a simplified procedure, which gives good approximations of the design points, by requiring only three classical FORMs and one interval analysis (IA), developed herein through an optimization procedure. FORM for HRA and its simplified formulation achieve a much improved efficiency than MCS by several orders of magnitude, and it can thus be applied to real-world engineering problems. Representative examples of stochastic dynamic analysis and performance-based engineering are presented.

Seismic Reliability of Long-Span Bridges Based on the First Order Reliability Method

2010 ◽  
Vol 163-167 ◽  
pp. 4032-4036
Author(s):  
Bu Yu Jia ◽  
Xiao Lin Yu ◽  
Heng Bin Zheng ◽  
Quan Sheng Yan ◽  
Wei Li
Keyword(s):  
Reliability Analysis ◽  
First Order Reliability Method ◽  
Seismic Reliability ◽  
Long Span Bridges ◽  
First Order ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Reliability Method ◽  
The Cross ◽  
Excursion Probability

In this paper, first order reliability method (FORM) is generalized to the seismic reliability analysis of long-span bridges and the first excursion probability of a single tower cable-stayed bridge is studied. The seismic motivation is firstly dispersed as a series of random variables. Then the cross velocities on the dispersed time points can be obtained by solving the motivation of the design checking points with FORM. The upper bound of first excursion probability is also obtained by integrating the cross velocities at different time. The results show that the seismic reliability analysis method based on the FORM is feasible and effective to solve the first excursion probability problem. The single tower cable-stayed bridge studied in this paper has a higher reliability under strong seismic.

Reliability analysis for a spar-supported floating offshore wind turbine

2017 ◽  
Vol 42 (1) ◽  
pp. 51-65 ◽  
Author(s):  
Abhinav Sultania ◽  
Lance Manuel
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Reliability Analysis ◽  
Wave Height ◽  
Return Period ◽  
Random Variables ◽  
Environmental Data ◽  
First Order Reliability Method ◽  
First Order ◽  
Reliability Method

The reliability analysis of a spar-supported floating offshore 5-MW wind turbine is the subject of this study. Environmental data from a selected site are employed in the numerical studies. Using time-domain simulations, the dynamic behavior of a coupled platform-turbine system is studied; statistics of tower and rotor loads as well as platform motions are estimated and critical combinations of wind speed and wave height identified. Long-term loads associated with a 50-year return period are estimated using statistical extrapolation based on loads derived from simulations. Inverse reliability procedures that seek appropriate fractile levels for underlying variables consistent with the target load return period are employed; these include use of (1) two-dimensional inverse first-order reliability method where extreme loads, conditional on wind speed and wave height random variables, are selected at median levels and (2) three-dimensional inverse first-order reliability method where variability in the environmental and load random variables is fully represented.

An Efficient Algorithm Based on First Order Reliability Method for Fatigue Reliability Analysis of Mechanical Components

2002 ◽  
Author(s):  
Jun Tang ◽  
Young Ho Park
Keyword(s):  
Fatigue Life ◽  
Reliability Analysis ◽  
Search Algorithm ◽  
Strain History ◽  
Fatigue Reliability ◽  
First Order Reliability Method ◽  
Reliability Factor ◽  
First Order ◽  
Reliability Method ◽  
Mechanical Components

The method for fatigue reliability analysis of mechanical components using the First-Order Reliability Method (FORM) reconciles accuracy and efficiency requirements for random process reliability problems under fatigue failure. However, the algorithm for solving FORM is still complex and time consuming. In this paper, the FORM that utilizes an efficient search algorithm is proposed for reliability assessment of the strain-based fatigue life. Using the proposed method, a family of reliability-defined ε-Nf curves, referred to as R-ε-Nf curves, is constructed. An empirical mean stress modified strain-life equation is also used as the performance function. The primary focus of this effort has been the implementation of the new algorithm of FORM to define reliability factors used in modifying the conventional ε-Nf curve to create a family of R-ε-Nf curves, based on the unique reliability factor rule. The proposed method employs the inverse FORM algorithm to achieve computational results, including reliability and the corresponding fatigue life. The method enables the application of fatigue life design for a given cyclic stress and/or strain history. A numerical example is presented to demonstrate the proposed method.

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