Rendering optimal design under various uncertainties

2019 ◽  
Vol 37 (1) ◽  
pp. 345-367
Author(s):  
Hui Lü ◽  
Kun Yang ◽  
Wen-bin Shangguan ◽  
Hui Yin ◽  
DJ Yu
Keyword(s):  
Reliability Analysis ◽  
Optimization Design ◽  
Design Method ◽  
Possibility Theory ◽  
Response Analysis ◽  
Analysis Method ◽  
Unified Framework ◽  
Central Difference ◽  
Content Type ◽  
Uncertain Variables

Purpose The purpose of this paper is to propose a unified optimization design method and apply it to handle the brake squeal instability involving various uncertainties in a unified framework. Design/methodology/approach Fuzzy random variables are taken as equivalent variables of conventional uncertain variables, and a unified response analysis method is first derived based on level-cut technique, Taylor expansion and central difference scheme. Next, a unified reliability analysis method is developed by integrating the unified response analysis and fuzzy possibility theory. Finally, based on the unified reliability analysis method, a unified reliability-based optimization model is established, which is capable of optimizing uncertain responses in a unified way for different uncertainty cases. Findings The proposed method is extended to perform squeal instability analysis and optimization involving various uncertainties. Numerical examples under eight uncertainty cases are provided and the results demonstrate the effectiveness of the proposed method. Originality/value Most of the existing methods of uncertainty analysis and optimization are merely effective in tackling one uncertainty case. The proposed method is able to handle the uncertain problems involving various types of uncertainties in a unified way.

A Probabilistic and Interval Hybrid Reliability Analysis Method for Structures with Correlated Uncertain Parameters

2015 ◽  
Vol 12 (04) ◽  
pp. 1540006 ◽  
Author(s):  
C. Jiang ◽  
J. Zheng ◽  
B. Y. Ni ◽  
X. Han
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Correlation Coefficients ◽  
Analysis Method ◽  
Analysis Model ◽  
Probability Interval ◽  
Uncertain Variables ◽  
Uncertainty Model ◽  
Sample Correlation ◽  
Hybrid Reliability

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.

A new jig-shape optimization method for the high aspect ratio wing

2018 ◽  
Vol 91 (1) ◽  
pp. 124-133
Author(s):  
Zhe Yuan ◽  
Shihui Huo ◽  
Jianting Ren
Keyword(s):  
Aspect Ratio ◽  
Shape Optimization ◽  
High Aspect Ratio ◽  
Optimization Design ◽  
Design Method ◽  
Aircraft Design ◽  
Optimization Method ◽  
Attack Angle ◽  
Structural Deformation ◽  
Content Type

Purpose Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed. Design/methodology/approach First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation. Findings After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account. Practical implications The new jig-shape optimization method can be well used for the high aspect ratio wing. Originality/value The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.

Wear Reliability Analysis Method Based on Random Process

2012 ◽  
Vol 155-156 ◽  
pp. 348-351
Author(s):  
Yu Tao Yan ◽  
Zhi Li Sun ◽  
Guang Wei Hu ◽  
Li Fang Liu
Keyword(s):  
Random Process ◽  
Reliability Analysis ◽  
Test Data ◽  
Design Method ◽  
Uniform Design ◽  
Surface Hardness ◽  
Analysis Method ◽  
Analysis Model ◽  
Function Fitting ◽  
Uniform Design Method

The random reliability analysis model for wear was established based on random process theory and wear research. The wear experiment scheme on load, sliding speed, surface hardness and bearing capacity of lubrication was instituted by the uniform design method, and carried out on a vertical universal friction/wear tester. The static wear predication model was established by the partial least squares based on test data. It is found that the wear extent obey to normal distribution by checkout of the probability paper and mathematic expectation function fitting and residuals distribution, the variance function fitting and residuals distribution based on the test data of random process. The reliability of definite working life was gained by calculating with established reliability model, and compared with test data, the analysis method is a valid method for wear reliability.

An adaptive collocation method for structural fuzzy uncertainty analysis

2020 ◽  
Vol 37 (9) ◽  
pp. 2983-2998
Author(s):  
Lei Wang ◽  
Chuang Xiong ◽  
Qinghe Shi
Keyword(s):  
Uncertainty Analysis ◽  
Collocation Method ◽  
Membership Function ◽  
Interval Uncertainty ◽  
Engineering Practice ◽  
Analysis Method ◽  
Content Type ◽  
Fuzzy Uncertainty ◽  
Uncertain Variables ◽  
The Membership Function

Purpose Considering that uncertain factors widely exist in engineering practice, an adaptive collocation method (ACM) is developed for the structural fuzzy uncertainty analysis. Design/methodology/approach ACM arranges points in the axis of the membership adaptively. Through the adaptive collocation procedure, ACM can arrange more points in the axis of the membership where the membership function changes sharply and fewer points in the axis of the membership where the membership function changes slowly. At each point arranged in the axis of the membership, the level-cut strategy is used to obtain the cut-level interval of the uncertain variables; besides, the vertex method and the Chebyshev interval uncertainty analysis method are used to conduct the cut-level interval uncertainty analysis. Findings The proposed ACM has a high accuracy without too much additional computational efforts. Originality/value A novel ACM is developed for the structural fuzzy uncertainty analysis.

Moment methods for C/SiC woven composite components reliability and sensitivity analysis

2014 ◽  
Vol 21 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Chunyuan Kong ◽  
Zhigang Sun ◽  
Xuming Niu ◽  
Yingdong Song
Keyword(s):  
Sensitivity Analysis ◽  
Reliability Analysis ◽  
Engineering Practice ◽  
Analysis Method ◽  
Woven Composite ◽  
Computationally Efficient ◽  
Central Difference ◽  
Moment Methods ◽  
Reliability Sensitivity ◽  
Reliability Sensitivity Analysis

AbstractA kind of reliability analysis method for C/SiC woven composite components was proposed, which is based on moment methods. Moment methods combining with perturbation method, the central difference method, as well as the Edgeworth series are applied to calculate the reliability of complex component for its effectivity and accuracy. The results computed by moment methods are sensitive to the distribution of parameters; thus, reliability sensitivity analysis has been performed. The reliability and sensitivity information of the complex components can be accurately and quickly obtained using a practical computer program. Finally, the proposed reliability-sensitivity analysis method is applied to CMCs components design. By comparing with Monte Carlo simulation, the numerical results demonstrate that the proposed approach provides accurate, convergent, and computationally efficient for finite element method-based reliability analysis in engineering practice.

Reliability based design method for buckling of steel columns in fire

2019 ◽  
Vol 11 (2) ◽  
pp. 167-187
Author(s):  
Andrei Kervalishvili ◽  
Ivar Talvik
Keyword(s):  
Reliability Analysis ◽  
Response Function ◽  
Elevated Temperatures ◽  
Design Method ◽  
Content Type ◽  
Practical Applications ◽  
Steel Columns ◽  
Steel Column ◽  
Parameter Ranges ◽  
In Fire

Purpose This paper aims to reliability analysis of axially loaded steel columns at elevated temperatures considering the probabilistic features of fire. Design/methodology/approach The response function used in the reliability analysis is based on the non-linear FEM calculations. The stochastic variability of temperature is integrated with the procedure similar to the parameters of loading and material properties. Direct Monte Carlo simulations (MCSs) are implemented for probabilistic analysis. Computational costs are reduced by polynomial approximation of the response function of the column. Findings A design method for practical applications in the common Eurocode format is proposed. The proposed method can be used to estimate the failure probability of a steel column in fire conditions. If standard reliability criteria are applied, the results of the steel column buckling capacity in the fire according to the proposed procedure deviate from the Eurocode results in certain parameter ranges. Originality/value The proposed method for design calculations makes use of the advantages of MCS results, while the need for the tedious amount of calculations for the end user are avoided as the predefined factors are implemented in the procedure of Eurocode format. The proposed method allows better differentiation of the fire probability in the capacity assessment compared to the existing design methods.

Tolerance–reliability analysis of mechanical assemblies for quality control based on Bayesian modeling

2019 ◽  
Vol 39 (5) ◽  
pp. 769-782 ◽  
Author(s):  
S. Khodaygan ◽  
A. Ghaderi
Keyword(s):  
Quality Control ◽  
Reliability Analysis ◽  
Bayesian Modeling ◽  
Industrial Applications ◽  
Mechanical Assembly ◽  
Assembly Quality ◽  
Content Type ◽  
Uncertain Variables ◽  
Mechanical Assemblies ◽  
Reliability Method

Purpose The purpose of this paper is to present a new efficient method for the tolerance–reliability analysis and quality control of complex nonlinear assemblies where explicit assembly functions are difficult or impossible to extract based on Bayesian modeling. Design/methodology/approach In the proposed method, first, tolerances are modelled as the random uncertain variables. Then, based on the assembly data, the explicit assembly function can be expressed by the Bayesian model in terms of manufacturing and assembly tolerances. According to the obtained assembly tolerance, reliability of the mechanical assembly to meet the assembly requirement can be estimated by a proper first-order reliability method. Findings The Bayesian modeling leads to an appropriate assembly function for the tolerance and reliability analysis of mechanical assemblies for assessment of the assembly quality, by evaluation of the assembly requirement(s) at the key characteristics in the assembly process. The efficiency of the proposed method by considering a case study has been illustrated and validated by comparison to Monte Carlo simulations. Practical implications The method is practically easy to be automated for use within CAD/CAM software for the assembly quality control in industrial applications. Originality/value Bayesian modeling for tolerance–reliability analysis of mechanical assemblies, which has not been previously considered in the literature, is a potentially interesting concept that can be extended to other corresponding fields of the tolerance design and the quality control.

Influence of oil nozzle structure parameters on oil injection direction

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yanzhong Wang ◽  
Guanhua Song ◽  
Wentao Niu ◽  
Yaping Zhang
Keyword(s):  
Flow Injection ◽  
Design Method ◽  
Slenderness Ratio ◽  
Jet Flow ◽  
Structure Parameters ◽  
Analysis Method ◽  
Content Type ◽  
Oil Injection ◽  
Dynamics Method ◽  
Nozzle Structure

Purpose The purpose of this paper is to provide an analytical method of jet flow injection direction and to determine the influence of oil nozzle structure parameters on oil injection direction, thus providing the design method of oil nozzle structure parameters. Design/methodology/approach A model of oil injection loss is established to analyze the influence of oil nozzle structure parameters on oil injection direction. The computational fluid dynamics method is used to simulate the process of the deviation of jet flow injection direction. The deviation of jet flow injection direction with different oil nozzle structure parameters is calculated and their variations are obtained. Moreover, the deviation of jet flow injection direction with different oil nozzle structure parameters is tested to verify the analysis results. Findings Results indicate that radial velocity caused the deflection of the oil injection direction. The deviation of jet flow increased as the nozzle slenderness ratio decreased. The design method of the nozzle slenderness ratio (greater than five) is proposed to avoid the deviation of injection direction, and it is necessary to consider the matching between the nozzle slenderness ratio and pipeline pressure. The computational results coincide well with the experimental results. Originality/value The research presented here analyzed the influence of oil nozzle structure parameters on oil injection direction via a numerical analysis method. It also leads to a design reference guideline that could be used in jet lubrication, thus controlling the direction of the injection jet accurately.

Research on anti-fatigue design method of welded structure oriented to stiffness coordination strategy

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chunliang Niu ◽  
Suming Xie ◽  
Tao Zhang
Keyword(s):  
Stress Concentration ◽  
Welded Joints ◽  
Optimization Design ◽  
Design Method ◽  
Implementation Process ◽  
Welded Structures ◽  
Content Type ◽  
Coordination Strategy ◽  
Fatigue Design ◽  
Welded Structure

PurposeIn order to obtain the relationship between the geometry and stress concentration of load-bearing welded joints, the fatigue design method of welded structures based on stiffness coordination strategy is studied.Design/methodology/approachBased on the structural stress theory, a new method for anti-fatigue design of welded structures oriented to stiffness coordination strategy is proposed, and the detailed implementation process of this method is given. This method is also called the three-stage anti-fatigue design method for welded structures, which includes three stages, namely, identification, analysis and relief of stress concentration.FindingsThrough the experimental analysis of welded joints in IIW standard, the effectiveness of stiffness coordination in welded joint design is proved. The method is applied to the design of welded parts and products, and the feasibility of the method in alleviating the phenomenon of stress concentration and improving the fatigue resistance of welded structures is verified.Originality/valueIn this study, based on the principle of coordinated design of weld stiffness, a three-stage anti-fatigue design method of welded structure is proposed. The method has practical value for the optimization design and anti-fatigue performance improvement of welded structure in engineering products.

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