Dynamic analysis and design of uncertain systems against random excitation using probabilistic method

In this paper, a method to obtain the sensitivity of eigenvalues and the random responses of the structure with uncertain parameters is proposed. The concept of the proposed method is that the perturbed equation of each uncertain substructure is obtained using the finite element method, and the perturbed equation of the overall structure is obtained using the mode synthesis method. By this way, the reduced order perturbed equation of the uncertain system can be obtained. And the response of the uncertain system is obtained using probability method. As a numerical example, a simple piping system is considered as an example structure. The damping and spring constants of the support are considered as the uncertain parameters. Then the variations of the eigenvalues, the correlation function and the power spectral density function of the responses are calculated. As a result, the proposed method is considered to be useful technique to analyze the sensitivities of eigenvalues and random response against random excitation in terms of the accuracy and the calculation time.     

斗轮堆取料机设计制造使用常见问题综述

斗轮堆取料机（以下简称为斗轮机）广泛应用于冶金、港口、电厂等行业．是大宗散装物料连续装卸机械。斗轮机在设计与制造过程中经常会发生一些易被忽视的问题。这往往在安装或使用过程中才被发现。对该问题进行综述。     

Economic-based design of engineering systems with degrading components using probabilistic loss of quality

The allocation of means and tolerances to provide quality, functional reliability and performance reliability in engineering systems is a challenging problem. Traditional measures to help select the best means and tolerances include mean time to failure and its variance; however, they have some shortcomings. In this paper, a monetary measure based on present worth is invoked as a more inclusive metric. We consider the sum of the production cost and the expected loss of quality cost over a planned horizon at the customer’s discount rates. Key to the approach is a probabilistic loss of quality cost that incorporates the cumulative distribution function that arises from time-variant distributions of system performance measures due to degrading components. The proposed design approach investigates both degradation and uncertainty in component. Moreover, it tries to obviate problems of current Taguchi’s loss function-based design approaches. Case studies show the practicality and promise of the approach.     

The strength analysis and probabilistic design of a bogie frame with incomplete probabilistic information

Journal of Mechanical Science and Technology - A bogie frame is a key component of high-speed rail; higher requirements of the safety and stability of the bogie frame are put forward with the...     

Quality chain design and optimization by multiple response surface methodology

To maintain optimal quality characteristics in the defined specification limits is a vital decision for any industry and service system. To avoid nonconformity in outputs, the stream of variations and their potential causes must be identified so that the response variables fall into desirable limits across the manufacturing or service chain. Response surface methodology is considered as a powerful technique to facilitate the analysis of the mentioned problem. This paper presents the general quality chain design problem as a mathematical program and also proposes a method to solve it using multiple response surface methodology. An example of multistage processes is analyzed by the proposed approach to show its efficacies numerically and analytically.     

地震勘探钻机的设计

针对我国地震勘探钻孔技术的现状和存在的问题,研制了适合我国国情的用于山地、丘陵、戈壁滩、森林地区钻进用的JSWS-30型山地钻机、JSWL-30型砾石钻机、JSWT-50型土层钻机、JQWS-30型森林地震勘探钻机,重点介绍了各种钻机的结构及性能特点。通过钻机在现场的试验,证明钻机具有良好的使用性能。     

可拓设计理论方法综述与展望

为了针对产品创新设计中的矛盾问题寻求最佳设计方案,提出一种可拓设计理论方法,该方法集理论、实践、科学、哲学和方法论为一体,具有设计目标清晰、冲突消解过程有序、方案输出结果满意等特点。通过分析比较发明问题解决理论、基于规则/实例推理、约束松弛、协商、回溯、可拓设计等常用于产品创新设计过程中的冲突问题消解方法,论述了可拓设计方法最大的特色在于模型化、形式化、定性与定量相结合,是一种智能化处理设计对象、设计系统的现代设计方法;系统介绍了可拓学和可拓设计的形成及相互关系、可拓设计的研究方法和设计原理,对可拓设计各步骤环节的研究现状进行了综述,论述了目前存在的不足及今后的发展方向与思路;阐述了可拓设计方法及其计算机实现的策略生成系统,对几种典型的可拓设计软件系统做了简要介绍;最后对全文进行总结,展望了今后的研究目标及需要解决的研究难点。     

Modeling and solving the bi-objective capacitated location-routing problem with probabilistic travel times

The location-routing problem (LRP) is a relatively new research area within location analysis that concerns simultaneously both the problems of location of facilities and routing of vehicles among the established facilities and the demand points. In this work, we address the capacitated LRP with probabilistic travel times, which may arise in many practical contexts in logistics and supply chain management, and present some bi-objective mathematical programming formulations to model the problem using different stochastic programming approaches. The first objective is to minimize the overall system-wide costs, while the second objective concerns minimization of the maximum delivery time to the customers. In all the cases, the deterministic equivalents of the stochastic models have been extracted. To solve the resulted models, a variable neighborhood descent-based heuristic is proposed and finally computational study is performed and numerical results are reported.     

Regression modeling and optimization of machinability behavior of glass-coir-polyester hybrid composite using factorial design methodology

Polymer-based composite materials posses superior properties such as high strength-to-weight ratio, stiffness-to-weight ratio, and good corrosive resistance and therefore, are preferred for high-performance applications such as in the aerospace, defense, and sport goods industries. Drilling is one of the indispensable methods for building products with composite panels. In this present work, an investigation has been carried out to evaluate mechanical and machinability characteristics of hybrid composites, E-glass, and natural coir fiber abundantly available in India. A regression model is developed for correlating the interactions of some drilling parameters such as drill bit diameter, spindle speed and feed rate, and their effects on responses such as thrust force, torque, and tool wear during drilling of glass-coir fiber reinforced hybrid composites by Design of Experiment techniques. Results indicated that feed rate is playing major role on the responses than other two variables.     

不确定性设计优化理论与方法研究

系统地开展了不确定性设计优化理论与方法研究,定义了设计不确定性、设计稳健性和设计可靠性等概念,阐述了不确定性设计优化理论体系框架,建立了不确定性设计优化模型,提出了解决不确定性设计优化建模、求解和计算复杂性问题的有效途径.     

基于响应面法的L型弯管概率可靠性及灵敏度研究

采用APDL语言对L型弯管进行参数化建模,将有限元法、响应面法和Monte-Carlo模拟法结合起来,通过有限元循环计算得到拟合响应面函数的样本,用含有交叉项的二次多项式对样本进行回归分析,得到响应变量(最大等效应力)和随机输入变量间的函数关系式,用此表达式来代替真实的响应面模型。通过输出响应变量的累计分布函数等相关数据,对L型弯管进行可靠性分析,通过对L型弯管进行灵敏度分析得出了对响应变量影响比较大的随机输入变量。     

用标准化手段提高航天产品设计文件质量

航天产品设计文件的质量可主要由其完整性、正确性、协调性和规范性(简称“四性”)来衡量，下面谈谈“四性”的内涵和中国三江航天集团是如何用标准化手段提高设计文件的“四性”的。     

变速器轻量化设计探索

近年来,随着能源危机的发生,汽车工业面临节能、减排的发展需要,而汽车的轻量化对汽车的节能、减排有十分重要的意义。变速器作为汽车动力总成的重要组成部分,其重量大约占了整车的5%。本文以手动变速器的设计为例,对变速器的齿轮、壳体、同步器、拨叉、轴承等设计的轻量化进行探讨,主要从材料、设计、制造等角度进行了分析对比,初步提出变速器轻量化设计的思路。     

机载雷达天线减速器的设计探讨

简单述机载雷达天线减速器的一种优化设计方法,减速级数及各级传动比的确定,并做有关的分析和论证。     

智能型天然气阀的系统化设计

天然气作为一种新兴能源，具有环保，廉价的特点，因而得到广泛的使用，如何解决用户在天然气使用方面的计量以及保证计量的可靠性便成了天然气使用的重要问题。这里应用工业设计思想，从系统的角度出发对天然气阀的机械系统进行了分析比较，得出了最佳设计方案，为天然气阀的设计奠定了基础。     

A probabilistic forecasting of oil pipeline lifetimes at the design stage

The oil pipeline lifetime distribution was found by the method of statistical simulation according to a determined formula, when the yield point, load, and dimensions of the section are subject to a normal distribution law. The expression for the limiting pressure of the beginning of yield under the joint action of circular, longitudinal, and temperature stresses has been obtained. On the basis of these data, the forecasting of lifetime factors of oil pipeline reliability at its design stage and building has been performed, and due to that environmental safety was enhanced.     

空间凸轮的反求设计及制造

从设计纺机空间凸轮的角度，分析了空间凸轮的设计方法和设计规律。运用反求的方法，对反求三坐标数据的测量和处理方法进行了阐述，同时对纺机空间凸轮的加工规律和特性进行了剖析，充分利用先进的CAD／CAM集成软件Pro／Engineer强大的设计和加工功能，比较系统地设计了纺机空间凸轮。利用Pro／Engineer加工模块，对纺机空间凸轮进行了数控加工，生成数控加工程序。     

Designing efficient methods for the tandem AGV network design problem using tabu search and genetic algorithm

A tandem AGV configuration connects all cells of a manufacturing facility/plant by means of non-overlapping, single-vehicle closed loops. Each loop has at least one additional P/D station, provided as an interface between adjacent loops. This study describes the development of tabu search and genetic algorithm procedures for designing tandem AGV systems. The objective is to minimize the maximum workload of the system. Both algorithms have mechanisms to prevent solutions with intersecting loops. The new algorithms and the partitioning algorithm presented by Bozer and Srinivasan are compared using randomly generated test problems. Results show that for large-scale problems, the partitioning algorithm often leads to infeasible configurations with crossed loops in spite of its shorter running time. However the newly developed algorithm avoids infeasible configurations and often yields better objective function values.     

Evaluation of the characteristics of the microelectrical discharge machining process using response surface methodology based on the central composite design

Evaluation of the characteristics of a microelectrical discharge machining (Micro-EDM) process is challenging, because it involves complex, interrelated relationships so a proper modeling approach is necessary to clearly identify the crucial machining variables and their interrelationships in order to initiate more effective strategies to improve Micro-EDM qualities (electrode wear (EW), material removal rate (MRR) and overcut). This paper uses a response surface method (RSM) based on the central composite design (CCD) for Micro-EDM problems with four EDM variables (peak current, pulse on-time, pulse off-time and electrode rotation speed). Experimental results indicate that peak current is the EDM variable that most affects the Micro-EDM qualities for SK3 carbon tool steel while pulse off-time had a significant interaction with that. The results show that RSM based on the CCD could efficiently be applied for the modeling of Micro-EDM qualities (EW, MRR, and overcut), and it is an economical way to obtain the performance characteristics of Micro-EDM process parameters with the fewest experimental data.     

电磁成像逆问题的初步求解及图像重建

从电磁层析成像(EMT)系统的数学模型出发,运用格林函数法对其逆问题进行理论分析,得到了表征EMT电磁逆问题的积分形式解,阐明了物场内电磁场与待测物场特性分布的关系.图像重建说明格林函数法求解EMT逆问题是可行的.