scholarly journals Multi-Fidelity Modeling-Based Structural Reliability Analysis with the Boundary Element Method

2017 ◽  
Vol 08 (03n04) ◽  
pp. 1740001 ◽  
Author(s):  
Llewellyn Morse ◽  
Zahra Sharif Khodaei ◽  
M. H. Aliabadi
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Reliability Analysis ◽  
Structural Reliability ◽  
Computational Cost ◽  
Response Surfaces ◽  
Second Order ◽  
Reliability Method ◽  
Fidelity Model ◽  
Element Method

In this work, a method for the application of multi-fidelity modeling to the reliability analysis of 2D elastostatic structures using the boundary element method (BEM) is proposed. Reliability analyses were carried out on a rectangular plate with a center circular hole subjected to uniaxial tension using Monte Carlo simulations (MCS), the first-order reliability method (FORM), and the second-order reliability method (SORM). Two BEM models were investigated, a low-fidelity model (LFM) of 20 elements and a high-fidelity model (HFM) of 100 elements. The response of these models at several design points was used to create multi-fidelity models (MFMs) utilizing second-order polynomial response surfaces and their reliability, alongside that of the LFM and the HFM, was evaluated. Results show that the MFMs that directly called the LFM were significantly superior in terms of accuracy to the LFM, achieving very similar levels of accuracy to the HFM, while also being of similar computational cost to the LFM. These direct MFMs were found to provide good substitutes for the HFM for MCS, FORM, and SORM.

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.

scholarly journals A Technique to Remove Second Order Singularity Application in the Boundary Element Method for Elastoplasticity Plane Stress Analysis

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
S.A. Bakar ◽  
A.L. Saleh
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Second Order ◽  
Timber Beam ◽  
Singularity Problem ◽  
Strain Formulation ◽  
Incremental Formulation ◽  
Plastic Stage ◽  
Plane Stress Analysis ◽  
Element Method

This paper presents a technique to establish the strain incremental formulation in the boundary element method applied to elastoplasticity problem. In this technique, the application of second order singularity problem is avoided, and only first order singularity problem is sufficient. The proposed technique is applied to analyse a timber beam structure at the plastic stage. The solution is compared with existing strain formulation method proposed by established publication. The result gives an improved solution compared with the existing method. The proposed technique is a simplified formulation where there is no second order singularity involved in the formulation.

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