An optimal design of solar water heating systems

Abstract

Based on the seismicity and tectonics of Taiwan area, a set of potential earthquake sources is identified. Using available attenuation laws and fault‐rupture model, the individual influences of potential sources are integrated into the probability distribution of maximum annual intensity and peak acceleration. The results are presented in the form of seismic risk maps for a 475‐year return period. Based on the result of this study, it concludes that the seismic hazard potential for the central region is moderate, but it is high for east‐coast region.

This paper also presents a reliability analysis method for safety evaluation of buried pipelines in Taiwan region. The results of the reliability analysis of the buried pipelines subjected to earthquake ground accelerations are presented and a fragility result for peak ground acceleration (PGA) studies is also constructed.     

Total System Reliability: Integrated Model for Growth and Test Termination

Reliability demonstration testing is not the most efficient method of assuring product reliability prior to shipment. It is costly, time consuming and has inherent technical and social limitations. The dilemma facing the reliability and quality engineer is whether to continue demonstration testing and risk shipping a product late or ship the product and risk warranty and field service returns. Either option can cause the company to lose significant market share and profit. This paper sets out to solve this dilemma by meeting both the time to market constraints and the product reliability goals. The weaknesses of existing reliability demonstration techniques are explored and a comprehensive methodology is introduced involving controlled development processes, stress testing, root cause determination and process change feedback mechanisms. All prototype products are manufactured on the final volume process line resulting in the early identification and correction of process‐related problems. Testing commences on the first available prototypes with system stress/robust testing being employed to stimulate failures, determine their root cause and correct them. Reliability growth modelling assesses the ongoing improvements occurring in reliability during the development cycle, while a statistical stopping rule is used to determine the optimal product release time without risking product warranty. The approach is applicable to systems incorporating both hardware and software elements. The methodology has been validated on three development projects of telecommunication systems comprising hardware and software. In addition to enhancing team behaviour and performance, the development times have been reduced by 14% and the ramp‐up time to full worldwide product shipments has been reduced by 50%. Copyright © 2005 John Wiley & Sons, Ltd.     

The use of reliability‐oriented field feedback information for product design improvement: a case study

In the innovative industry, four major trends are found to influence product quality and reliability: the increase in product complexity, the strong pressure on time to market, the increasing global economy, and the decreasing tolerance for quality problems. Thus, it becomes more difficult to anticipate all potential failures during the product development process. In this context, an efficient field feedback process should be in place to react to the unanticipated deviations in product performance. Based on a case study made in an innovative company, this paper shows that the problem is not so much in the information collection as in the inherent quality of the information and in the manner the information is processed. Therefore, a new method, presented in this paper, was developed to classify and prioritize field data and to upgrade it into information that can be used for design improvement according to the dominant classes of failures using the four‐phase roller coaster model. Although this newly generated information is richer than raw field data it is not yet detailed enough to allow direct design optimization. Therefore, a second upgrading stage, based on design of experiments, was developed. It uses a method that combines physics‐of‐failure (bottom‐up) and field information (top‐down). As traditional DoE mainly deals with largely time‐independent quality data obtained during the manufacturing process the approach had to be modified to deal with time‐dependent reliability data. Case study results show that it is a promising approach for characterizing and resolving failure mechanisms also in innovative companies. Copyright © 2008 John Wiley & Sons, Ltd.     

Conceptual robustness in simultaneous engineering: A formulation in continuous spaces

This paper develops a robust and distributed decision-making procedure for mathematically modeling and computationally supporting simultaneous decision-making by members of an engineering team. The procedure (1) treats variations in the design posed by other members of the design team asconceptual noise; (2) incorporates such noise factors into conceptually robust decision-making; (3) provides preference information to other team members on the variables they control; and (4) determines whether to execute the conceptually robust decision or to wait for further design certainty. While Changet al. (1994) extended Taguchi's approach to such simultaneous decision-making, this paper uses a continuous formulation and discusses the foundations of the procedure in greater detail. The method is demonstrated by a simple distributed design process for a DC motor, and the results are compared with those obtained for the same problem using sequential decision strategies in Krishnanet al. (1991).     

What's new in reliability engineering?

Reliability engineering is responding to the trend to computer-aided design (CAD), and the current emphasis on improving competitiveness through quality. Islands of automation addressing reliability for both hardware design and software engineering exist which are not yet connected, though government–industry teams are developing integrated software packages of reliability (and maintainability) tools. TQM (total quality management) principles are being adopted in many industries, and the U.S. Qualified Manufacturers List (QML) programme, which requires qualification of a process rather than a product, is now used for procuring microcircuits. However, government regulations remain a barrier to creating a ‘quality culture’. ISO 9000 is seen by industry as a requirement for international competitiveness, but criticized by some as counterproductive. Research and development of reliability engineering tools reflect the need for implementation in CAD frameworks, and fuzzy logic analysis has attracted the attention of the theorists.     

Reliability Analysis Using Chaotic Particle Swarm Optimization

Reliability analysis is an important and practical way of considering uncertainty in an engineering system. In practical engineering, the limit state functions are usually implicit in terms of random variables. Traditional reliability analysis methods are time‐consuming and require derivative computing. In this paper, particle swarm optimization (PSO) is applied to reliability analysis by combining it with the first‐order reliability method. To improve the global search performance, chaotic PSO (CPSO) was proposed by combining PSO with a chaotic system. CPSO‐based reliability analysis is described and applied to four classic examples. The results show that implementation of CPSO‐based reliability analysis is easy and can yield a reliability index and design point with good accuracy. The proposed method was applied to analyze the reliability of a circular tunnel in different cases. The results show that the CPSO algorithm is very efficient at solving global optimization problems and is a good approach for reliability analysis. Copyright © 2014 John Wiley & Sons, Ltd.     

Reliability analysis for the design of an inflator

Product reliability is determined at its design stage and must be identified to adequately evaluate the feasibility of the current design. Reliability prediction provides the means to design verification and optimum modification. A design team must detect any potential reliability problems before the completion of the product design. This paper presents an approach to include the use of a reliability block diagram for reliability prediction, a fault tree analysis for detecting possible failures, and the axiomatic design procedure in the product design evaluation process. The discussion includes the reliability analysis of a passenger side airbag inflator design. The modification of the current inflator design is also discussed.     

Adaptive improved response surface method for reliability-based design optimization

Reliability-based design optimization (RBDO) requires the evaluation of probabilistic constraints (or reliability), which can be very time consuming. Therefore, a practical solution for efficient reliability analysis is needed. The response surface method (RSM) and dimension reduction (DR) are two well-known approximation methods that construct the probabilistic limit state functions for reliability analysis. This article proposes a new RSM-based approximation approach, named the adaptive improved response surface method (AIRSM), which uses the moving least-squares method in conjunction with a new weight function. AIRSM is tested with two simplified designs of experiments: saturated design and central composite design. Its performance on reliability analysis is compared with DR in terms of efficiency and accuracy in multiple RBDO test problems.     

基于价值工程的产品优化设计研究

目的 弥补目前价值工程应用到产品优化设计中时,只考虑减少成本,忽视改善质量的局限。方法 运用价值工程的对象选择原则和方法,对预期寿命周期高,已经在市场上销售一段时间的产品进行价值分析,提出初步的设计方向,再通过对某一批次的产品维修记录的统计分析,引入产品功能可靠度的概念,对价值工程提出的设计方向进行修正。结果 将功能可靠度与价值工程的分析相结合,有效弥补传统价值工程指导产品优化设计时,只关注成本而忽视质量的缺点。结论 通过实例进行验证,最终结果表明,功能可靠度与价值工程相结合提出的优化设计方案,在改善产品质量的同时,也有效降低了成本。     

Quality and reliability information integration for design evaluation of fixture system reliability

Quality and reliability are two important factors in manufacturing‐system design. However, the analysis and optimization of manufacturing‐system reliability and product quality are normally conducted separately in practice. There is no general framework to integrate these two important factors, quantitatively analyze the interactions between them, and further study their integrated effects on the manufacturing‐system performance. In this paper, the QR‐Co‐Effect of product/part quality and manufacturing‐system component reliability is investigated in an assembly fixture system. The concept, model and analysis of QR‐Co‐Effect are addressed in this paper. Copyright © 2001 John Wiley & Sons, Ltd.     

Dynamic reliability-based robust design optimization with time-variant probabilistic constraints

With the increasing complexity of engineering systems, ensuring high system reliability and system performance robustness throughout a product life cycle is of vital importance in practical engineering design. Dynamic reliability analysis, which is generally encountered due to time-variant system random inputs, becomes a primary challenge in reliability-based robust design optimization (RBRDO). This article presents a new approach to efficiently carry out dynamic reliability analysis for RBRDO. The key idea of the proposed approach is to convert time-variant probabilistic constraints to time-invariant ones by efficiently constructing a nested extreme response surface (NERS) and then carry out dynamic reliability analysis using NERS in an iterative RBRDO process. The NERS employs an efficient global optimization technique to identify the extreme time responses that correspond to the worst case scenario of system time-variant limit state functions. With these extreme time samples, a kriging-based time prediction model is built and used to estimate extreme responses for any given arbitrary design in the design space. An adaptive response prediction and model maturation mechanism is developed to guarantee the accuracy and efficiency of the proposed NERS approach. The NERS is integrated with RBRDO with time-variant probabilistic constraints to achieve optimum designs of engineered systems with desired reliability and performance robustness. Two case studies are used to demonstrate the efficacy of the proposed approach.     

A co-operation framework for product–process integration in engineering design

Many different studies have stressed the importance of co-operation in engineering design. This paper is based on an empirical study carried out over 18 months and based on fieldwork where the researcher worked in a design team as a mechanical engineer. The question of product–process integration is particularly critical in mechanical engineering and requires the development of specific co-operative procedures. Our results stress the importance of artefacts as intermediary objects in the design process and more specifically in the development of co-operative processes. We developed a framework centred on three conceptual levels:

• At product level, where we developed specific artefacts within a CAD environment, referred to herein as co-operating features,

• At organisation level, where we stress the importance of developing organisational learning and a new interface role,

• At actor level, where we stress the importance of developing reflective practices.

This conceptual framework aims to provide a foundation to develop instrumental settings for design co-operation.     

中小型制造类企业的可靠性管理研究

以IEC 60 300 <可信性管理>系列标准为依据,分析了国内中小型制造类企业的实际特点,并在此基础上对其可靠性管理工作进行了研究.探讨了建立健全中小型制造类企业可靠性管理的组织机构,包括阐述可靠性保证组织机构的设置原则和机构设置与机构职能;对可靠性管理工作的各个环节包括可靠性计划、可靠性设计、可靠性数据资料管理、可靠性设计评审及可靠性监督和保证等各方面的工作内容及程序逐一进行了描述.在科学的基础上对中小型制造类企业可靠性管理的具体应用进行了探索.     

Statistical monitoring performance for startup operations in a feedback control system

Previously, it has been held that statistical process control (SPC) and engineering process control (EPC) were two distinct domains for process improvement. However, we specifically consider the impact for integrating the two approaches on a first‐order dynamic system with ARIMA disturbances. We show how to model and analyze this system over a range of practical conditions. Our work results in a set of response surfaces that characterize the performance of the integrated design. We also compare these results to the case where the SPC and EPC policies are applied separately. In general, we find that the EPC approach performs best in terms of minimizing error, but that we can reduce the number and magnitude of adjustments using the integrated monitoring and control approach. This work also further supports our earlier findings that the integrated design is effective on complex dynamic systems during the initial transient or startup period. Copyright © 2001 John Wiley & Sons, Ltd.     

Reliability Prediction Based on Variation Mode and Effect Analysis

The possibility of predicting the reliability of hardware for both components and systems is important in engineering design. Today, there are several methods for predicting the reliability of hardware systems and for identifying the causes of failure and failure modes, for example, fault tree analysis and failure mode and effect analysis. Many failures are caused by variations resulting in a substantial effect on safety or functional requirements. To identify, to assess and to manage unwanted sources of variation, a method called probabilistic variation mode and effect analysis (VMEA) has been developed. With a prescribed reliability, VMEA can be used to derive safety factors in different applications. However, there are few reports on how to derive the reliability based on probabilistic VMEA, especially for transmission clutch shafts. Hence, the objective of this article was to show how to derive system reliability based on probabilistic VMEA. In particular, wheel loader automatic transmission clutch shaft reliability is investigated to show how different sources of variation affect reliability. In this article, a new method for predicting system reliability based on probabilistic VMEA is proposed. The method is further verified by a case study on a clutch shaft. It is shown that the reliability of the clutch shaft was close to 1.0 and that the most significant variation contribution was due to mean radius of the friction surface and friction of the disc. Copyright © 2012 John Wiley & Sons, Ltd.     

TRIZ: Engineering Methodologies to Improve the Process Reliability

Research of solutions to problem in existing processes often deals with the tendency to follow mental schemes because of the psychological inertia. This study illustrates a knowledge‐based systematic methodology of inventive problem solving for the effective development of new systems and solutions, a theory that consists of theoretical foundation, analytical and knowledge‐based tools, applicable in conjunction with other creativity and engineering methodologies. The TRIZ (Theory of Inventive Problem Solution) applicability in process reliability can develop new and effective solutions thanks to the examination of contradiction, different prospective, and points of view. The systematic innovation process provides a platform to integrate heterogeneous resources and tools opening the problem‐solving methodology to new and different interdisciplinary approaches. The deconstruction and identification of issues to analyze the problems in their context and in relation to other factors are adopted in many areas of industrial production as well as in the more general problem‐solving matters. In particular, this study will show how TRIZ can be used in process optimization rather than research and development where this methodology is commonly adopted. This case represents a practical application of the TRIZ to increase quality and reliability in regard to a manufacturing process of an industry that designs and builds molds and equipment for the production of aluminum food containers. Copyright © 2016 John Wiley & Sons, Ltd.     

支持并行设计的产品数据管理系统的研究和开发

提出了支持并行设计的产品数据管理（PDM）系统的基本框架；着重分析了支持并行设计的产品数据管理的关键技术与实现方法，讨论了产品数据定义与管理、集成开发团队的人员组织模式、并行设计过程与工作流管理、设计版本的管理等关键技术，提出了通过构建内部高速局域网络来实现企业并行设计的产品数据管理系统的思想。     

Reliability sensitivity analysis with random and interval variables

In reliability analysis and reliability‐based design, sensitivity analysis identifies the relationship between the change in reliability and the change in the characteristics of uncertain variables. Sensitivity analysis is also used to identify the most significant uncertain variables that have the highest contributions to reliability. Most of the current sensitivity analysis methods are applicable for only random variables. In many engineering applications, however, some of uncertain variables are intervals. In this work, a sensitivity analysis method is proposed for the mixture of random and interval variables. Six sensitivity indices are defined for the sensitivity of the average reliability and reliability bounds with respect to the averages and widths of intervals, as well as with respect to the distribution parameters of random variables. The equations of these sensitivity indices are derived based on the first‐order reliability method (FORM). The proposed reliability sensitivity analysis is a byproduct of FORM without any extra function calls after reliability is found. Once FORM is performed, the sensitivity information is obtained automatically. Two examples are used for demonstration. Copyright © 2009 John Wiley & Sons, Ltd.     

Reliability technology using GO methodology: A review

Goal‐oriented (GO) methodology is a graphic inductive method mapping the system structure, its function constitute, characteristics, and working principle visually based on decision tree. Recently, the studies on reliability technologies for GO method of complex systems have been gotten a lot of attention by scholars because of the obvious advantages of modeling and analysis power. Indeed, the GO method has been applied in reliability and safety analysis of various areas, such as transportation and power systems, to prove its value. Thus, this paper provides a brief review of the GO method from aspects of providing its development history and its engineering applications and expounding its development of the theory of the GO method. At last, the future directions of GO method are discussed.     

Second‐order reliability method‐based inverse reliability analysis using Hessian update for accurate and efficient reliability‐based design optimization

First‐order reliability method (FORM) has been mostly utilized for solving reliability‐based design optimization (RBDO) problems efficiently. However, second‐order reliability method (SORM) is required in order to estimate a probability of failure accurately in highly nonlinear performance functions. Despite accuracy of SORM, its application to RBDO is quite challenging due to unaffordable numerical burden incurred by a Hessian calculation. For reducing the numerical efforts, a quasi‐Newton approach to approximate the Hessian is introduced in this study instead of calculating the true Hessian. The proposed SORM with the approximated Hessian requires computations only used in FORM, leading to very efficient and accurate reliability analysis. The proposed SORM also utilizes a generalized chi‐squared distribution in order to achieve better accuracy. Furthermore, SORM‐based inverse reliability method is proposed in this study. An accurate reliability index corresponding to a target probability of failure is updated using the proposed SORM. Two approaches in terms of finding an accurate most probable point using the updated reliability index are proposed. The proposed SORM‐based inverse analysis is then extended to RBDO in order to obtain a reliability‐based optimum design satisfying probabilistic constraints more accurately even for a highly nonlinear system. The numerical study results show that the proposed reliability analysis and RBDO achieve efficiency of FORM and accuracy of SORM at the same time. Copyright © 2014 John Wiley & Sons, Ltd.