Robust design of an interior hard trim to improve occupant safety in a vehicle crash

Head injury ranks among the top contributors in automobile accidents. Consequently, although styling is treated important, safety of occupants in a crash receives preemptive priority in the design of automotive interior components. Additionally, the Federal Motor Vehicle Safety Standard (FMVSS) 201 has laid down certain requirements to be fulfilled by automobile manufacturers for producing a safe vehicle. One of the requirements stipulate dummy equivalent of the Head Injury Criteria, i.e. HIC(d) value for the interior components of a vehicle to be below 1000 under certain stated conditions. In this paper, we provide a robust design approach to achieve the requirements for one such interior component, viz. an interior hard trim that covers the pillar closest to the driver's head on the left-hand side of the vehicle.     

Robust optimal-parameter design approach for tolerance design problems

A robust optimal-parameter design method, henceforth called the TGAOA, to solve tolerance design problems has been investigated. Tolerance affects system performance and leads to violation of design constraints. The TGAOA approach conducts global exploration by using a genetic algorithm and exploits optimal offspring via the Taguchi method. It is able to effectively reduce the impact of parameter variations in reaching robust optimal-solutions as allowed by the tolerance. Two design examples are employed to evaluate the performance of the new method. The first is for a mixed H₂/H_∞ optimal PID controller under varying PID component specifications, plant uncertainty, and other external unknown disturbance. The second involves a 13-variable test function, which includes quadratic, linear, and polynomial forms to illustrate the general robustness and computational efficiency, for which comparisons are also made with its predecessors of genetic algorithm and hybrid Taguchi-genetic algorithm.     

先进制造技术的核心技术

产品设计思想创新和设计技术创新是先进制造技术的核心。在研究先进制造技术的体系和特点的基础上,探讨了先进制造的设计思想和设计技术的主要内容。     

Nonlinear Elastic Wave Spectroscopy (NEWS) Techniques to Discern Material Damage,Part I: Nonlinear Wave Modulation Spectroscopy (NWMS)

Abstract

The level of nonlinearity in the elastic response of materials containing structural damage is far greater than in materials with no structural damage. This is the basis for nonlinear wave diagnostics of damage, methods which are remarkably sensitive to the detection and progression of damage in materials. Nonlinear wave modulation spectroscopy (NWMS) is one exemplary method in this class of dynamic nondestructive evaluation techniques. The method focuses on the application of harmonics and sum and difference frequency to discern damage in materials. It consists of exciting a sample with continuous waves of two separate frequencies simultaneously, and inspecting the harmonics of the two waves, and their sum and difference frequencies (sidebands). Undamaged materials are essentially linear in their response to the two waves, while the same material, when damaged, becomes highly nonlinear, manifested by harmonics and sideband generation. We illustrate the method by experiments on uncracked and cracked Plexiglas and sandstone samples, and by applying it to intact and damaged engine components.     

抱朴守拙——家居产品设计中的美学体现与回归

目的 以日常生活用品的创新为切入点,分析归纳抱朴守拙美学在家居产品设计中的体现,以期拓宽中式美学融入家居产品设计的方法与路径。方法 将文化学概论中的文化层次理论和唐纳德·诺曼的三层认知概念相结合,构建文化转译思路,从朴拙美学与现代设计应用的现状出发,通过梳理相关设计原理并结合多个应用案例,从形式美、功能美和内涵美等方面分析朴拙美学在家居产品设计中的影响机制与应用体现,重点阐述了形态朴素、功能适宜,以及符号简单的具象化设计应用方法。结论 包含现代家居产品物象转译与呈现的朴拙美学风格,是现代设计理念和中式传统文化结合发展的缩影。从本能形式、行为功能和反思内涵等角度提出设计创新策略,为现代家居产品的内涵式与外延式发展提供了理论框架与实现路径。     

Response Surface Optimization in the Presence of Internal Noise With Application to Optimal Alignment of Carbon Nanotubes

Internal noise, which means fluctuation of input factors around their set values, is common in many experiments in the physical and engineering sciences. Existing methods for response surface optimization in the presence of internal noise typically adopt a two-step approach: (a) fitting a response model as a function of the set value and (b) using Monte Carlo methods to account for internal noise while optimizing the response. In this article, motivated by a problem in optimizing alignment of carbon nanotubes (CNT), we propose a Bayesian approach for response surface optimization in the presence of internal noise. A unit-free and interpretable measure to quantify the strength of internal noise is proposed. Suitable objective functions or performance measures consistent with the overall goal of optimizing the response function are identified, methods for estimating them from available experimental data are suggested, and simulations are conducted to compare them with respect to their ability to account for internal noise in the optimization problem. The loss accrued by ignoring the internal noise in the optimization problem is quantified and studied via simulation. The proposed method is demonstrated through its application in the CNT alignment problem.     

正交试验在粉末药型罩制造工艺参数研究中的应用

文章将正交设计应用于粉末药型罩压制工艺参数研究,分析了影响粉末药型罩性能的工艺参数。确定了试验方案,根据方案完成了穿孔深度试验,并根据试验结果进行数据分析。分析表明：4个因素的影响大小依次为压罩压力、药型罩圆径跳、保压时间、阴模旋转速度。确定了较优的生产工艺条件,利用数学模型计算得到较优条件下的射孔弹穿深并完成了验证试验。     

Using Genetic Algorithms to Design Experiments: A Review

Genetic algorithms (GAs) have been used in many disciplines to optimize solutions for a broad range of problems. In the last 20 years, the statistical literature has seen an increase in the use and study of this optimization algorithm for generating optimal designs in a diverse set of experimental settings. These efforts are due in part to an interest in implementing a novel methodology as well as the hope that careful application of elements of the GA framework to the unique aspects of a designed experiment problem might lead to an efficient means of finding improved or optimal designs. In this paper, we explore the merits of using this approach, some of the aspects of design that make it a unique application relative to other optimization scenarios, and discuss elements which should be considered for an effective implementation. We conclude that the current GA implementations can, but do not always, provide a competitive methodology to produce substantial gains over standard optimal design strategies. We consider both the probability of finding a globally optimal design as well as the computational efficiency of this approach. Copyright © 2014 John Wiley & Sons, Ltd.     

颗粒填料复合式膜生物反应器运行参数对膜污染的影响

为了探讨颗粒填料在减缓膜污染方面的作用,通过正交实验,研究了颗粒填料复合式膜生物反应器(HMBR)中膜通量、悬浮污泥浓度、颗粒填料体积三个运行参数对膜污染的影响.在实验过程中用平均膜过滤阻力的上升速率(K)来表征膜污染速率.结果表明,膜污染速率与膜通量、悬浮污泥浓度成正比,与填料体积成反比,填料颗粒能够有效地减缓膜污染和提高膜生物反应器的运行稳定性.各运行参数对膜污染速率的影响次序为:膜通量>悬浮污泥浓度>填料体积.在本实验条件下HMBR的最佳操作参数是:X=4g MLSS/L,C=20%,J=4.5L/(m2·h).     

Conceptual robustness in simultaneous engineering: An extension of Taguchi's parameter design

Simultaneous engineering processes involve multifunctional teams; team members simultaneously make decisions about many parts of the product-production system and aspects of the product life cycle. This paper argues that such simultaneous distributed decisions should be based on communications about sets of possibilities rather than single solutions. By extending Taguchi's parameter design concepts, we develop a robust and distributed decision-making procedure based on such communications. The procedure shows how a member of a design team can make appropriate decisions based on incomplete information from the other members of the team. More specifically, it (1) treats variations among the designs considered by other members of the design team asconceptual noise; (2) shows how to incorporate such noises into decisions that are robust against these variations; (3) describes a method for using the same data to provide preference information back to the other team members; and (4) provides a procedure for determining whether to release theconceptually robust design or to wait for further decisions by others. The method is demonstrated by part of a distributed design process for a rotary CNC milling machine. While Taguchi's approach is used as a starting point because it is widely known, these results can be generalized to use other robust decision techniques.     

Design By Additive Manufacturing: an application in aeronautics and defence

Additive Manufacturing (AM) is a major challenge for the deployment of Industry 4.0 in companies. Thus, it becomes essential to control the potential contributions of this innovative process from the early stages of design. In this paper, previous Design and Creativity For/With/Through AM approaches are first reviewed comprehensively and classified into distinct categories according to their main purpose and application. Then, they are integrated into a modular framework as part of a global 5-step design approach to promote AM in the whole design process: the Design By Additive Manufacturing (DBAM) methodology. A validation of the method is then proposed on an industrial case study from the aeronautics and defence sector, thereby fostering the complete exploitation of AM potentials and the development of AM-conformal designs.     

Taguchi-based design of experiments in training POD-RBF surrogate model for inverse material modelling using nanoindentation

This paper investigates the use of a surrogate model based on Proper Orthogonal Decomposition (POD) and Radial Basis Functions (RBF) for calibrating the nanoindentation-based loading of an elastic–plastic material. Using Taguchi design of experiments and Analysis of Variance (ANOVA), the total number of finite element-based training points is reduced for input parameters that exhibited lower significance. It is found that ANOVA-based sensitivity information can be used to reduce the number of training points without significantly affecting model accuracy. It is also observed that RBFs capable of conforming nonlinearly perform better when the spatial distance between training points increases. Furthermore, for some RBFs the performance is further tuned by choice of the shape parameters. Finally, it is demonstrated that the surrogate model’s performance remains stable under the effect of random noise. Thereby, this study provides a general framework for solving a nanoindentation-based material modelling inverse problem using the POD–RBF technique.     

电子光学系统最优化设计中的非线性规划:应用与比较

以电子光学系统中发射系统为实例，从收敛速度、搜索效果、整体收敛性等几个方面，系统地对非线性规划的五种搜索方法在电子光学系统设计中的应用进行分析和比较，得出了一些有价值的结果。计算表明Rosenbrock法是电子光学系统最优化设计中最值得推荐的方法。     

Noise Strategy in Robust Design: What Aspects of Noise Factors are Important in Quality Engineering?

The correlation and variances of noise factors induced during robust design may influence the success of the quality engineering process. A model-based approach is employed to quantify these influences. The results are then checked using two case studies. It was determined that for systems having no significant three-factor interactions, correlation among the noise factors can be safely neglected and it is often helpful to amplify the magnitude of induced noise. Otherwise, noise factors should be used that match the true magnitude and correlation in field conditions. Based on these results, a procedure is suggested for a noise strategy in quality engineering.     

Manufacturing process selection in engineering design. Part 1: the role of process selection

Whilst material selection methods are becoming mature, the selection of processes has been neglected — particularly after the preliminary design stages. This paper presents a view of current approaches to selection issues in engineering design with particular reference to process selection techniques. The need is highlighted for more focused selection techniques once a manufacturing task has been identified. A new methodology to aid the creation of task-based process selection procedures is outlined in Part 2 (A.M. Lovatt, H.R. Shercliff, J. Mater. Des., 19 (1998) 217–230).     

超声辐照对HepG2细胞存活率影响的实验研究

为探讨超声辐照对体外培养的HepG<,2>细胞存活力的影响,采用正交设计方法,选定声强、占空比和辐照时间3因素,每因素5水平的参数条件设计正交表,对贴壁培养的HepG<,2>细胞进行超声辐照,之后继续培养24h后行MTT(噻唑蓝)实验检测细胞存活率,期间光学显微镜观察培养板内的细胞生长状况及形态.结果表明:当超声声强大...     

Manufacturing process selection in engineering design. Part 2: a methodology for creating task-based process selection procedures

Part 1 (A.M. Lovatt, H.R. Shercliff, J. Mater Des., 19 (1998) 205–215) of this paper identified a need for a methodology to help to create selection procedures for specific manufacturing tasks, where the material and processing operation have, to some extent, already been defined. This paper develops such a methodology, and its aims are twofold: firstly to guide the designer through defining the requirements of the design and identifying the attributes of the relevant subset of processes which must be considered; secondly to lead the designer through an evaluation of a design considering both technical viability (including the product quality during processing and in the finished part), and economic viability. A critical development in this work is the incorporation of process modelling into the selection procedure, as a tool for capturing the coupling of material and process characteristics which govern whether the processing and performance targets can be met.     

The Role of Statistical Design of Experiments in Six Sigma: Perspectives of a Practitioner

Six Sigma has now been well recognized as an effective means of attaining excellence in the quality of products and services. It entails the use of statistical thinking as well as management and operational tools to bring about fundamental improvements. This article explains, in a nonmathematical language, the rationale and mechanics of design of experiments as seen in its deployment in Six Sigma. It also outlines the way in which the design of experiments has been utilized in the past for quality improvement, culminating in its important role in Six Sigma. An appreciation of the changing scope of experimental design applications over the years and in the future would provide useful perspectives on the significance of Six Sigma in an organization's quest for quality excellence.     

Manufacturing cell design with alternative routings in generalized group technology: reducing the complexity of the solution space

In the presence of alternative routings, the manufacturing cell design involves the solution of a large number of (simple) cell-formation problems. We present a bounding scheme which examines all combinations of alternative routings and solves only a few cell-formation problems, thereby limiting the solution space which is searched heuristically. This leads to increased reliability for the solutions obtained. The resulting algorithm is shown to be applicable for problems arising in practice frequently, when the initial design includes relatively few exceptional elements, and machine duplication and/or genuine multiple process plans are used correctively, to eliminate the remaining intercellular traffic.