Adjoint Gradient-enhanced Kriging Model for Time-dependent Reliability Analysis

2019 ◽  
Author(s):  
Yi Gao ◽  
Yongming Liu
Keyword(s):  
Reliability Analysis ◽  
Kriging Model ◽  
Time Dependent ◽  
Adjoint Gradient

Advanced time-dependent reliability analysis based on adaptive sampling region with Kriging model

2020 ◽  
Vol 234 (4) ◽  
pp. 588-600
Author(s):  
Yan Shi ◽  
Zhenzhou Lu ◽  
Ruyang He
Keyword(s):  
Reliability Analysis ◽  
Failure Probability ◽  
Surrogate Model ◽  
Adaptive Sampling ◽  
Computational Cost ◽  
Kriging Model ◽  
Time Dependent ◽  
Computational Time ◽  
Optimization Strategy ◽  
Dependent Failure

Aiming at accurately and efficiently estimating the time-dependent failure probability, a novel time-dependent reliability analysis method based on active learning Kriging model is proposed. Although active surrogate model methods have been used to estimate the time-dependent failure probability, efficiently estimating the time-dependent failure probability by a fewer computational time remains an issue because screening all the candidate samples iteratively by the active surrogate model is time-consuming. This article is intended to address this issue by establishing an optimization strategy to search the new training samples for updating the surrogate model. The optimization strategy is performed in the adaptive sampling region which is first proposed. The adaptive sampling region is adjustable by the current surrogate model in order to provide a proper candidate samples region of the input variables. The proposed method employs the optimization strategy to select the optimal sample to be the new training sample point in each iteration, and it does not need to predict the values of all the candidate samples at every time instant in each iterative step. Several examples are introduced to illustrate the accuracy and efficiency of the proposed method for estimating the time-dependent failure probability by simultaneously considering the computational cost and precision.

scholarly journals Time-Dependent Reliability Analysis of Reinforced Concrete Beams Subjected to Uniform and Pitting Corrosion and Brittle Fracture

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1820
Author(s):  
Mohamed El Amine Ben Seghier ◽  
Behrooz Keshtegar ◽  
Hussam Mahmoud
Keyword(s):  
Reinforced Concrete ◽  
Brittle Fracture ◽  
Reliability Analysis ◽  
Pitting Corrosion ◽  
Structural Reliability ◽  
Time Dependent ◽  
State Function ◽  
Rc Beams ◽  
Highly Nonlinear ◽  
Reliability Method

Reinforced concrete (RC) beams are basic elements used in the construction of various structures and infrastructural systems. When exposed to harsh environmental conditions, the integrity of RC beams could be compromised as a result of various deterioration mechanisms. One of the most common deterioration mechanisms is the formation of different types of corrosion in the steel reinforcements of the beams, which could impact the overall reliability of the beam. Existing classical reliability analysis methods have shown unstable results when used for the assessment of highly nonlinear problems, such as corroded RC beams. To that end, the main purpose of this paper is to explore the use of a structural reliability method for the multi-state assessment of corroded RC beams. To do so, an improved reliability method, namely the three-term conjugate map (TCM) based on the first order reliability method (FORM), is used. The application of the TCM method to identify the multi-state failure of RC beams is validated against various well-known structural reliability-based FORM formulations. The limit state function (LSF) for corroded RC beams is formulated in accordance with two corrosion types, namely uniform and pitting corrosion, and with consideration of brittle fracture due to the pit-to-crack transition probability. The time-dependent reliability analyses conducted in this study are also used to assess the influence of various parameters on the resulting failure probability of the corroded beams. The results show that the nominal bar diameter, corrosion initiation rate, and the external loads have an important influence on the safety of these structures. In addition, the proposed method is shown to outperform other reliability-based FORM formulations in predicting the level of reliability in RC beams.

Uncertain time-dependent reliability analysis of corroded RC structures applying three-term conjugate method

2020 ◽  
Vol 115 ◽  
pp. 104599 ◽  
Author(s):  
Mansour Bagheri ◽  
Seyed Abbas Hosseini ◽  
Behrooz Keshtegar ◽  
José A.F.O. Correia ◽  
Nguyen-Thoi Trung
Keyword(s):  
Reliability Analysis ◽  
Time Dependent ◽  
Rc Structures ◽  
Uncertain Time
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