A new hybrid reliability index definition and its application to the structure buckling reliability analysis of supercavitating projectiles

2016 ◽  
Vol 21 (4) ◽  
pp. 467-471
Author(s):  
Ling Zhou ◽  
Zhitao Li ◽  
Jingzhuang Han ◽  
Nan Zhang
2018 ◽  
Vol 5 (2) ◽  
pp. 139
Author(s):  
Salman Al Farisi ◽  
Rukmi Sari Hartati ◽  
I Wayan Sukerayasa

The need for electricity in this global era is increasing, so that a more reliable electrical system is needed. A reliable system cannot be separated from interference, so there needs to be a system reliability analysis and power loss to the feeder by configuring the network. This research was conducted to find the reliability index value in the form of interference frequency and duration of interference (SAIFI and SAIDI). In one Tabanan feeder the results obtained exceed the standard so reconfiguration is performed Based on the analysis obtained before reconfiguration, the reliability index for SAIFI is 6,7456 (failure / year) and SAIDI is 11,4767 (hour / year) and power loss by 6,27 %. After reconfiguration of Tabanan feeder, the reliability index was better, for SAIFI is 5.2475 (disturbance / year) and SAIDI is 9,8798 (hour / year), the power loss was 2.82%. Sanggulan feeder is a new feeder reconfiguration result from Tabanan feeder, where the analysis was carried out to find out the reliability index of Sanggulan feeder, it was obtained the SAIFI value of 4.5753 (disturbance / year) and SAIDI of 9.5297 (hour / year) and power loss of 4,80%.


2014 ◽  
Vol 136 (3) ◽  
Author(s):  
C. Jiang ◽  
G. Y. Lu ◽  
X. Han ◽  
R. G. Bi

Compared with the probability model, the convex model approach only requires the bound information on the uncertainty, and can make it possible to conduct the reliability analysis for many complex engineering problems with limited samples. Presently, by introducing the well-established techniques in probability-based reliability analysis, some methods have been successfully developed for convex model reliability. This paper aims to reveal some different phenomena and furthermore some severe paradoxes when extending the widely used first-order reliability method (FORM) into the convex model problems, and whereby provide some useful suggestions and guidelines for convex-model-based reliability analysis. Two FORM-type approximations, namely, the mean-value method and the design-point method, are formulated to efficiently compute the nonprobabilistic reliability index. A comparison is then conducted between these two methods, and some important phenomena different from the traditional FORMs are summarized. The nonprobabilistic reliability index is also extended to treat the system reliability, and some unexpected paradoxes are found through two numerical examples.


2015 ◽  
Vol 12 (04) ◽  
pp. 1540006 ◽  
Author(s):  
C. Jiang ◽  
J. Zheng ◽  
B. Y. Ni ◽  
X. Han

This paper proposes a probability-interval mixed uncertainty model considering parametric correlations and a corresponding structural reliability analysis method. First of all, we introduce the sample correlation coefficients to express the correlations between different kinds of uncertain variables including probability and interval variables. Then dependent parameters are transformed into independent ones through a matrix transformation. A reliability analysis model is put forward, and an efficient method is built to obtain the reliability index or failure probability interval of the structure. Finally, four numerical examples are provided to verify the validity of the method.


2020 ◽  
Vol 868 ◽  
pp. 166-172
Author(s):  
Chandrashekhar Mahato ◽  
Pavel Kuklík

The Churches of the Broumov region are well known for their unique baroque architecture, distinct shapes, sizes, and constitutes an integral part of the Czech cultural heritage. The St. Barbara’s Church that has been studied in this article, is in the Otovice village of Broumov. It was built in the year 1726 by Bavarian architects Christoph Dientzenhofer and Kilian Ignaz and is significant because of its religious, artistic and historic values. The main objective of this study is to evaluate the structural safety and stability of St. Barbara’s Church based on a probabilistic approach. A deterministic assessment of the structure is carried out and the results are assessed concerning the present site condition. Depending upon the observed damages, a condition for failure is defined for the structure. The uncertainties in the material parameters are considered and reliability analysis is performed to determine the reliability index, probability of failure and influence of different material parameters in the structural stability.


Author(s):  
Zhen Hu ◽  
Sankaran Mahadevan ◽  
Xiaoping Du

Limited data of stochastic load processes and system random variables result in uncertainty in the results of time-dependent reliability analysis. An uncertainty quantification (UQ) framework is developed in this paper for time-dependent reliability analysis in the presence of data uncertainty. The Bayesian approach is employed to model the epistemic uncertainty sources in random variables and stochastic processes. A straightforward formulation of UQ in time-dependent reliability analysis results in a double-loop implementation procedure, which is computationally expensive. This paper proposes an efficient method for the UQ of time-dependent reliability analysis by integrating the fast integration method and surrogate model method with time-dependent reliability analysis. A surrogate model is built first for the time-instantaneous conditional reliability index as a function of variables with imprecise parameters. For different realizations of the epistemic uncertainty, the associated time-instantaneous most probable points (MPPs) are then identified using the fast integration method based on the conditional reliability index surrogate without evaluating the original limit-state function. With the obtained time-instantaneous MPPs, uncertainty in the time-dependent reliability analysis is quantified. The effectiveness of the proposed method is demonstrated using a mathematical example and an engineering application example.


2013 ◽  
Vol 405-408 ◽  
pp. 576-579
Author(s):  
Yong Hua Cao ◽  
Chuan Zhi Huang

The reliability theory based analysis is more advanced and reasonable compared with the traditional methods for slope stability analysis. Limit equilibrium method is usually used to evaluate the stability of a slope. In this paper, a new reliability analysis method is obtained based on JC method and multi sliding surface method which a new limit equilibrium method developed by Huang. Then, this new method is applied for a wharf slope. The sliding surface get from the safety factor is not the same as that from reliability index though they are close to each other. The safety factor or reliability index get from Fellenius method is smaller than that from other method. The safety factor or reliability index get from multi sliding surface method is close to that from Bishops method. The reliability index can be more reasonable after the standard deviation of the soil property index is deduced with random field theory.


2010 ◽  
Vol 163-167 ◽  
pp. 3099-3102
Author(s):  
Fei Kang ◽  
Jun Jie Li ◽  
Zhen Yue Ma

This paper presents a new method to simultaneously search for the minimum reliability index and the critical probabilistic slip surface of earth slopes. By introducing the Hasofer-Lind reliability index, the probabilistic slope stability analysis problem is modeled as a constrained optimization problem. A recently proposed intelligent global optimization algorithm differential evolution with a penalty function is adopted to solve the constrained optimization problem. Numerical results on two slopes show that the propose technique is efficient and practical to reliability analysis of earth slopes.


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