A knowledge-based system for materials selection in mechanical engineering design
S.M. Sapuan
Abstract
This paper studies various work on the development of computerized material selection system. The importance of Knowledge-based system (KBS) in the context of concurrent engineering is explained. The study of KBS in material selection in an engineering design process is described. The development in materials databases, which sometimes serve as material selection packages, is also discussed. The use of KBS in material selection and the application in the domain of polymeric-based composite are chosen as typical examples. 2001 Published by Elsevier Science Ltd.
1. Introduction
Materials selection is a task normally carried out by design and materials engineers. Gutteridge and Water- man [1] described the aim of materials selection as the identification of materials, which after appropriate manufacturing operations, will have the dimensions, shape and properties necessary for the product or component to demonstrate its required function at the lowest cost. For the purpose of material selection, thousands of data would be needed to characterize all the grades of materials. Many selection systems are available to help design engineers to choose the most suitable materials. At the most basic
level, design engineers could use tables of material properties in data books. However, data sheets are incomplete and once published, they are difficult to update. Dodd and Fairfull [2] described how information about engineering materials, can be divided into two main categories, i.e. data and knowledge. Data is defined as the results of measurements, whereas knowledge represents the connections between items of data, the source of this knowledge, which contributes to an understanding of the results. Both the computerized database and the KBS of material selection will be described in the following sections.
2. The material database for materials selection
2.1. Supporting data and rigorous logic for the hypothesis and obseruation
In recent years, attention is being made to the use of computer systems to store and process data regarding the properties of materials. It enables the designers to achieve large capacity and rapid retrieval from a computer database to provide easy access to the materials data. According to Prasad [3], materials are the common elements enumerating parts in a product realization process. Nowadays, design engineers normally rely on the materials that they are familiar with. However, when design requirements exceed the constraints of such materials or exceed the constraints on material properties, concurrent engineering teams must consider alternative materials. With direct online access to a materials database, the concurrent engineering teams could select materials that are lighter, stronger and lower in cost. Assuming that the impact of such substitutions can be analyzed or simulated, the teams could easily make an optimum selection of
materials for the available processes, conserve materials for each process and thus, reduce material waste.
White [4] emphasized the importance of computer aided materials selection as books have several drawbacks as they are often outdated before reaching the bookshelves. It is very difficult to index them to find answers or to sort data in the manner of your choice.
A computerized system, which provides access to materials data, is not necessarily a materials selection system, although access to data is essential to facilitate selection.
2.2. Critical review
This section reviews the development of computerized materials databases that enabled designers to select the materials in mechanical engineering design application. The development of material databases has been reported by Harmer [5] , Breuer et al [6-10], Baur [11-12] , Michaeli [13] , Ashby [14-15] and Cebon and Ashby [16-17] .
Harmer [5] reported that various database systems have been developed for plastics, elastomers and rubbers such as the Cambridge Materials Selector (CMS) , CAMPUS, Selector II, Plaspec, CenBASE/Materials, Mat. DB, Plastics Design Library .Engineered Materials Abstracts, FUNDUS, Prospector Plus, Polymat, SPAO, Pro-Concept, Explorer, Platt’s Polymerscan, Standards Infodisk, Pira Abstracts,
Packaging Science and Technology Abstracts, Chem-Intell and Weldasearch.
Computer-aided material pre-selection by uniform standards (CAMPUS) is a widely used materials database for plastics [6-10]. A product similar to that of CAMPUS is a database concerned with the selection of long fiber reinforced plastics. This system is called FUNDUS and it allows the distribution of material information from the producer to the designer end-user [11-13]. As such, it is of interest to all who work with sheet molding compound (SMC) , bulk molding compound ?.BMC or glass-mat thermoplastic (GMT) materials as reported by Baur [11-12] and Michaeli et al. [13] . CAMPUS and FUNDUS have features, which allow the user to view all properties for any listed product, print the data for any product search the database for products satisfying specific property requirements, select and view properties for comparison, and sort according to specific requirement in ascending or descending order. Ashby [14, 15] and Cebon and Ashby [16-17] developed a computerized materials selection system called Cambridge Materials Selector (CMS). The system uses materials selection charts, which are a way of displaying material property data through the use of optimization procedures. The selection process depends on implementing performance indices, a combination of material properties, which if maximized, optimizes performance. The charts are developed to present the materials, and the performance indices, so that the most suitable selection of materials and shape can be carried out.
机械工程设计选材基础知识
S.M. Sapuan
摘要
本文致力于研究对各种材料选择的电脑化系统发展。并对以基础知识的系统在并行工程环境（KBS）的重要性进行了解释。KBS的研究在材料选择方面由一个工程设计过程来描述。材料数据库的发展，和选材服务，也被讨论到了。在材料选择KBS和使用中的聚合物基复合材料领域的应用是选材典型的例子。
2001年由Elsevier科学有限公司出版。
1. 简介
材料选择通常是设计和材料工程师一项任务。加特里奇和水人[1]中是这样描述选择材料的:经过适当的制造业务，将有尺寸，形状和性能的产品或组件要以最低的成本展示其规定功能的材料选择的目标。对于选材的目的，成千上万的数据将需要所有的材料的特性。许多选择系统可以帮助设计工程师选择最合适的材料。在最基本的层面上，设计工程师可利用材料性能数据手册表。但是，数据表是不完整的，一旦公布，他们是难以更新。多德和范福 [2]描述了有关工程材料的资料，可分为两大类，即数据和知识的分歧。数据被定义为测量的结果，而信息代表之间的数据，在这方面的知识，这有助于对结果的认识源项目的连接。无论是计算机化的数据库和材料选择的KBS将在以下各节描述。
2.针对对材料选择的材料数据库
2.1支持这一假设的数据和严密的逻辑
近年来，关注正在面向计算机系统来存储和处理数据的有关材料的性能。它使得设计
者能够在实现大容量和快速的从一个计算机数据库里检索到资料数据。据普拉萨德[3]，材料是在列举部分产品实现过程的共同要素。如今，设计工程师通常依赖于材料，他们所熟悉的。然而，当超过设计要求这些材料的或超过材料特性的，并行工程团队必须考虑替代材料。随着直接在线访问材料数据库，并行工程团队可以选择的材料，重量更轻，更强，成本更低。假设，这种替代的影响可以分析或模拟，团队可以轻而易举地把一个可用进程的最佳选择材料，节约每一个程序的材料，因此，减少材料浪费是必须的。
白[4]强调了计算机选型辅助材料的重要性，图书有几个缺点，他们往往在到达的书架得时候已经过时。这使得他们很难找到答案指标进行排序或在您选择的方式的数据。
电脑化系统，它提供了访问数据的材料，并不一定是材料选择系统，虽然对数据的访问是必要的，以方便选择。
2.2 严格审查
本节回顾了计算机化的材料数据库，使设计人员选择了机械工程设计中的应用材料的发展。材料数据库的发展哈默曾报道[5]，布鲁尔等[6-10]，鲍尔[11-12]，Michaeli [13]，阿什比[14-15]和Cebon和Ashby [16-17] 。
哈默[5]报道，各种数据库系统已用于塑料，橡胶等材料的选择剑桥（CMS）校园，选择二，材料，橡胶垫发展。数据库，塑料设计库。文摘工程材料，眼底，勘探者另外，市产管办，临概念，探险家，普拉特的Polymerscan，标准Infodisk，皮拉文摘，包装科学与技术文摘，化学，网络和搜索。
计算机辅助材料前通过统一标准的选择（CAMPUS）是一种广泛使用的塑料材料数据
库[6-10]。一个产品类似CAMPUS，与长纤维选择有关的数据库增强塑料。这个系统被称为眼底，它允许信息从材料到设计生产销售的最终用户[11-13]。因此，它是关系到所有谁与片状模塑料（SMC）的，散装模塑料(BMC)或玻璃垫热塑性（GMT）的材料由鲍尔报道[11-12]和Michaeli等。 [13]。校园及眼底有特点，它允许用户查看任何列出的产品的所有属性，打印任何产品搜索数据，满足特定性能要求，选择和查看比较性质的产品数据库，并按照升序排序的具体要求或降序。阿什比[14，15]和Cebon和Ashby [16-17]开发一个计算机化的材料选择系统，称为剑桥材料选择器（CMS）的。该系统使用材料的选择图表，这是一种显示，通过优化程序使用材料性能数据的方法。甄选过程由实施性能指标而定，一个物质属性的组合，而如果最优化性能。图表的开发，以目前的材料，和性能指标，使最合适的材料和形状可以进行选择。
