检索结果-内蒙古大学图书馆

reliability-based design optimization of an automotive structure using a variable uncertainty

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING 2016年第10期230卷 1314-1323页

作者： Lim, Woochul Jang, Junyong Kim, Shinyu Lee, Tae Hee Kim, Jungho Lee, Kyungwon Lee, Changkun Kim, Yongsuk Hanyang Univ Dept Automot Engn Seoul South Korea Gen Motors Korea Ctr Tech Inchon South Korea

reliability-based design optimization is an optimization technique based on the stochastic approach. Many studies using this approach assume the uncertainty in the design variable to be constant. However, when the uncertainty depends on the values of the design variable, this assumption results in the wrong conclusions. Therefore, the uncertainty should be considered as a variable in reliability-based design optimization. The uncertainty in the thickness during optimization, such as the tolerance, had been assumed to be a constant in automotive structures. However, in practice, the tolerance of the thickness depends on the nominal thickness. Hence, in this paper, reliability-based design optimization of an automotive structure such as an engine cradle and a body-in-white with a variable uncertainty is carried out. General Motors Korea provides the tolerance guide which defines the dependence between the nominal thickness and the tolerance. The information is adopted to define the variable uncertainty. Thus, the variable uncertainty can modify the uncertainty with respect to the design point, resulting in an accurate reliability estimation. Finally, reliability-based design optimization with a variable uncertainty is performed using the Akaike information criterion method which determines the fittest distribution of the performance based on the maximum likelihood estimation of the candidate distributions. Consequently, the automotive structures are optimized to reduce the mass while still satisfying the target reliabilities of the performances when considering a variable uncertainty.

关键词： Akaike information criterion body-in-white engine cradle reliability-based design optimization tolerance guide variable uncertainty

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization with cooperation between support vector machine and particle swarm optimization

引用

ENGINEERING WITH COMPUTERS 2013年第2期29卷 151-163页

作者： Yang, I-Tung Hsieh, Yi-Hung Natl Taiwan Univ Sci & Technol Dept Construct Engn Taipei 106 Taiwan

reliability-based design optimization (RBDO) is concerned with designing an engineering system to minimize a cost function subject to the reliability requirement that failure probability should not exceed a threshold. Conventional RBDO methods are less than satisfactory in dealing with discrete design parameters and complex limit state functions (nonlinear and non-differentiable). Methods that are flexible enough to address the concerns above, however, come at a high computational cost. To enhance computational efficiency without sacrificing model flexibility, we propose a new RBDO framework: PS2, which combines Particle Swarm optimization (PSO), Support Vector Machine (SVM), and Subset Simulation (SS). SS can efficiently estimate small failure probabilities, based on which SVM is adopted to evaluate the reliability of candidate solutions using binary classification. PSO is employed to solve the discrete optimization problem. Primary emphasis is placed upon the cooperation between SVM and PSO. The cooperation is mutually beneficial since the SVM classifier helps PSO evaluate the feasibility of solutions with high efficiency while the optimal solutions obtained by PSO assist in retraining the SVM classifier to attain better accuracy. The PS2 framework is implemented to find the optimal design of a ten-bar truss, whose component sizes are selected from a commercial standard. The reliability constraints are non-differentiable with two failure modes: yield stress and buckling stress. The interactive process between PSO and SVM contributes greatly to the success of the PS2 framework. It is shown that in various trials the PS2 framework consistently outperforms both the double-loop and single-loop approaches in terms of computational efficiency, solution quality, and model flexibility.

关键词： reliability-based design optimization Particle swarm optimization Subset simulation Support vector machine Metaheuristics Simulation optimization

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization With Confidence Level for Non-Gaussian Distributions Using Bootstrap Method

引用

JOURNAL OF MECHANICAL design 2011年第9期133卷 091001页

作者： Noh, Yoojeong Choi, Kyung K. Lee, Ikjin Gorsich, David Lamb, David Univ Iowa Coll Engn Dept Mech & Ind Engn Iowa City IA 52242 USA USA RDECOM TARDEC Warren MI 48397 USA

For reliability-based design optimization (RBDO), generating an input statistical model with confidence level has been recently proposed to offset inaccurate estimation of the input statistical model with Gaussian distributions. For this, the confidence intervals for the mean and standard deviation are calculated using Gaussian distributions of the input random variables. However, if the input random variables are non-Gaussian, use of Gaussian distributions of the input variables will provide inaccurate confidence intervals, and thus yield an undesirable confidence level of the reliability-based optimum design meeting the target reliability beta(t). In this paper, an RBDO method using a bootstrap method, which accurately calculates the confidence intervals for the input parameters for non-Gaussian distributions, is proposed to obtain a desirable confidence level of the output performance for non-Gaussian distributions. The proposed method is examined by testing a numerical example and M1A1 Abrams tank roadarm problem. [DOI:10.1115/1.4004545]

关键词： reliability-based design optimization input statistical model confidence level non-Gaussian distribution bootstrap method

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization of river-sea-going ship based on agent model technology

引用

MARINE STRUCTURES 2024年 94卷

作者： Kang, Yuhan Pei, Zhiyong Ao, Lei Wu, Weiguo Wuhan Univ Technol Sch Naval Architecture Ocean & Energy Power Engn Wuhan 430063 Peoples R China Wuhan Univ Technol Cruise & Yacht Res Ctr Green & Smart River Sea Going Ship Wuhan 430063 Peoples R China Hubei Prov Engn Res Ctr Green & Smart River Sea Go Wuhan 430063 Peoples R China

The common ship structural optimization design is a deterministic method without considering uncertain factors, whereas the reliability-based design optimization (RBDO) can compensate for this deficiency. The RBDO of ship structure is a multi-parameter, high-dimensional, and high-nonlinear optimization solver. There exists a difficulty in guaranteeing accuracy and efficiency due to massive computation. In this study, the high-precision agent model for the limit state of ship hold structure is established based on agent model technology, including BP neural network, Radial Basis Function neural network, and Support Vector Machine combined with SMOTE oversampling algorithm. Furthermore, the reliability computation program is developed using Monte Carlo Simulation Method. A river-sea-going ship is considered the research object. The definition of rules, structural direct calculation result, and reliability requirement within all life cycles are considered boundary conditions. The RBDO system is constructed by the simulated annealing algorithm to investigate the lightweight structure. The established system can improve the efficiency and accuracy of the RBDO, which is significant for the ship's structural optimization design.

关键词： Agent model Monte Carlo simulation method reliability-based design optimization River-sea-going ship SMOTE algorithm

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization of wind turbine drivetrain with integrated multibody gear dynamics simulation considering wind load uncertainty

引用

STRUCTURAL AND MULTIDISCIPLINARY optimization 2017年第1期56卷 183-201页

作者： Li, Huaxia Cho, Hyunkyoo Sugiyama, Hiroyuki Choi, K. K. Gaul, Nicholas J. Univ Iowa Dept Mech & Ind Engn Iowa City IA 52242 USA RAMDO Solut LLC Iowa City IA 52240 USA

This study aims to develop an integrated computational framework for the reliability-based design optimization (RBDO) of wind turbine drivetrains to assure the target reliability under wind load and gear manufacturing uncertainties. Gears in wind turbine drivetrains are subjected to severe cyclic loading due to highly variable wind loads that are stochastic in nature. Thus, the failure rate of drivetrain systems is reported to be higher than the other wind turbine components, and improving drivetrain reliability is critically important in reducing downtime caused by gear failures. In the numerical procedure developed in this study, a wide spatiotemporal variability for wind loads is considered using 249 sets of wind data to evaluate probabilistic contact fatigue life in the sampling-based RBDO. To account for wind load uncertainty in evaluation of the tooth contact fatigue, multiple drivetrain dynamics simulations need to be run under various wind load scenarios in the RBDO process. For this reason, a numerical procedure based on the multivariable tabular contact search algorithm is applied to the modeling of wind turbine drivetrains to reduce the overall computational time while retaining the precise contact geometry required for considering the gear tooth profile optimization. An integrated computational framework for the wind turbine drivetrain RBDO is then developed by incorporating the wind load uncertainty, the rotor blade aerodynamics model, the drivetrain dynamics model, and the probabilistic contact fatigue failure model. It is demonstrated that the RBDO optimum for a 750 kW wind turbine drivetrain obtained using the procedure developed in this study can achieve the target 97.725% reliability (2 sigma quality level) with only a 1.4% increase in the total weight from the baseline design, which had a reliability of 8.3%. Furthermore, it is shown that the tooth profile optimization, tip relief introduced as a design variable, prevents a large increase of the f

关键词： reliability-based design optimization Wind turbine drivetrain Wind load uncertainty Multibody dynamics Gears Contact fatigue life reliability

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization for fatigue damage analysis

引用

INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2015年第5-8期76卷 1021-1030页

作者： Ibrahim, M. Haisam Kharmanda, G. Charki, A. Univ Angers LARIS ISTIA F-49000 Angers France Lund Univ Div Solid Mech SE-22100 Lund Sweden

The objective of reliability-based design optimization (RBDO) is to design structures which should be both economic and reliable. The existing methods lead to very high computational cost, local optima, and weak convergence stability. In this paper, we present a new methodology of RBDO, leading to global solutions without additional computing cost for the reliability evaluation. The safety factor formulation for linear and nonlinear cases has been used to reduce efficiently the computational time. This technique is fundamentally based on a study of the sensitivity of the limit state function with respect to the design variables. In order to demonstrate analytically the efficiency of this methodology, the optimality conditions are then used. The presented application on fatigue damage analysis shows the advantages of the optimum safety factor (OSF) for treating complex structural problems.

关键词： reliability-based design optimization Structural reliability Safety factors Fatigue damage analysis

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization for box-booms considering strength degradation and random total working time

引用

JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY 2012年第7期26卷 2045-2049页

作者： Wang, Zhonglai Li, Gang Huang, Hong-Zhong Zhang, Xiao-Ling Li, Yanfeng Univ Elect Sci & Technol China Sch Mech Elect & Ind Engn Chengdu 611731 Sichuan Peoples R China

Box-booms are widely used in some cranes. The strength of box-booms would continuously deteriorate with the use of time. In this paper, gamma process is employed to describe strength degradation when dealing with the overall stability of the box-boom. Furthermore, the total working time is not deterministic but random because of the random arrivals of tasks and the random working time of every task. By accounting for strength degradation and the random total working time, a time-dependent reliability-based design optimization (RBDO) model for the box-boom is proposed. An engineering case is used to illustrate the proposed model.

关键词： Box-boom Strength degradation Gamma process reliability-based design optimization Total random working time

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization of rotating FGM cylindrical shells with temperature-dependent probabilistic frequency constraints

引用

AEROSPACE SCIENCE AND TECHNOLOGY 2017年 68卷 223-239页

作者： Hamzehkolaei, Naser Safaeian Miri, Mahmoud Rashki, Mohsen Univ Sistan & Baluchestan Dept Civil Engn POB ***-161 Zahedan Iran Univ Sistan & Baluchestan Dept Architecture POB ***-161 Zahedan Iran

In this study, the reliability-based design optimization (RBDO) of rotating functionally graded cylindrical shells (FGCSs) subjected to temperature dependent probabilistic frequency constraints is investigated. The uncertain parameters such as FG material properties and the shell thermo-mechanical loads are considered as random variable in RBDO. To decrease model uncertainty, the effect of initial thermal stresses are efficiently included in elasticity-based vibration equations of the shell and the powerful differential quadrature method (DQM) is employed to accurately determine the shell frequency parameters. An efficient RBDO framework based on the hybrid weighted average simulation method (WASM) and DQM together with the particle swarm optimization (PSO) method is then presented for design optimization of the FGCSs. A key feature of proposed hybrid DQ-WASM-PSO is that only one simulation run is required for WASM during entire optimization process of the FGCS, even if the distribution type of input variables and/or the system target reliability level be changed. The influence of temperature rise, temperature-dependence of FGM properties, annular velocity, PDFs of the random variables, and convection heat transfer coefficient of the shell inside fluid on the RBDO results are carried out. Parametric study indicates that exact evaluation of the initial thermal stresses, temperature dependence of the FGM properties and convection heat transfer coefficient have considerable effect on optimization results. (C) 2017 Elsevier Masson SAS. All rights reserved.

关键词： reliability-based design optimization Rotating FGM cylindrical shell Temperature-dependent probabilistic frequency constraint Flexible algorithm Hybrid DQ-WASM-PSO

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization of volume fraction distribution in functionally graded composites

引用

COMPUTATIONAL MATERIALS SCIENCE 2013年 69卷 435-442页

作者： Noh, Y. J. Kang, Y. J. Youn, S. J. Cho, J. R. Lim, O. K. Keimyung Univ Dept Mech & Automot Engn Taegu 704701 South Korea Pusan Natl Univ Sch Mech Engn Pusan 609735 South Korea Res & Dev Inst Midas IT Gyeonggi 463400 South Korea

Functionally graded material (FGM) has a continuous and functional distribution of volume fractions of constituent particles, which leads to superior thermo-mechanical performance to classical laminated composite materials. Since the thermo-mechanical characteristics of an FGM depend on the volume fraction distribution, it is important to tailor appropriate volume fraction distribution that satisfies the desired performance requirements under given loading and boundary conditions. Even though numerical optimization technique may serve as an excellent material tailoring tool, the capacity of current manufacturing techniques of FGM may not yield the target volume fraction. To deal with uncertainty in the manufacturing process, a reliability-based design optimization (RBDO) for FGM composite is proposed. In RBDO, a finite number of volume fractions of homogenized FGM layers and material properties are considered as random variables, with statistical information such as mean, standard deviation, and statistical distributions. design of experiments and response surface models are used to obtain explicit forms of thermal stresses for RBDO formulation. It is observed through the numerical experiment that the RBDO finds the optimized volume fraction distribution with high reliability, such that the graded layers do not fail in the presence of manufacturing uncertainty. (c) 2012 Elsevier B.V. All rights reserved.

关键词： Functionally graded composites Graded layer Volume fraction Stress ratio reliability-based design optimization

来源：评论

学校读者我要写书评

暂无评论

reliability-based design optimization methodology for enhancing performance and efficiency in catalyst manufacturing for polymer electrolyte membrane fuel cells

引用

ENERGY CONVERSION AND MANAGEMENT 2024年 322卷

作者： Vaz, Neil Choi, Jaeyoo Kim, Sangwon Ju, Hyunchul Inha Univ Dept Mech Engn Inha Ro 100 Inchon 22212 South Korea Inha Univ FOUR Educ & Res Team Overcoming Mech Challenges Ca 100 Inha ro Incheon 22212 South Korea Korea Inst Sci & Technol KIST Europe Saarbrucken Germany Saarland Univ Transferctr Sustainable Electrochem D-66125 Saarbrucken Germany

Polymer Electrolyte Membrane Fuel Cells (PEMFCs) have emerged as an alternative to internal combustion engines, offering higher efficiency and reduced environmental impact. High component costs, particularly the cathode catalyst layer (CL), pose a significant barrier to widespread commercialization. This study addresses this challenge by optimizing the material and design of the cathode CL. Traditional deterministic design optimization (DDO) approaches have been explored but often fail to account for inherent uncertainties introduced during the manufacturing process. To overcome this limitation, we propose a data-driven reliability-based design optimization (RBDO) approach to optimize key CL design parameters, including the weight ratio of ionomer to carbon (wtI/C), the weight ratio of Pt to carbon (wtPt/C), the porosity of cathode CL (epsilon cCL), and platinum loading (LPt), to maximize cell voltage (Vcell), considering CL manufacturing costs (CostCL) and power density of membrane electrode assembly (P(center dot)MEA) as performance constraints. Compared to a typical PEMFC stack with LPtaligned to Department of Energy targets of 0.125 mg/cm2, results of the DDO show that Vcell is improved by 12 mV, with a reliability of 49 % for CostCL and 99.97 % for P(center dot)MEA, respectively. In contrast, the RBDO approach provides a reliability of 95 % for CostCL and 97.95 % for P(center dot)MEA, at the expense of a 32 mV drop in Vcell.

关键词： Polymer electrolyte membrane fuel cell reliability-based design optimization Dimensional uncertainties Monte Carlo simulation Dynamic Kriging surrogate Deterministic design optimization

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：