Search Results for improvement analysis

Life-cycle engineering is a part-, system-, or process-related tool for the investigation of environmental parameters based on technical and economic measures. This article focuses on life-cycle engineering as a method for evaluating impacts. It describes the four steps of life-cycle analysis, namely, goal definition and scoping, inventory analysis, impact assessment and interpretation, and improvement analysis. The article discusses the applications of life-cycle analysis results and presents a case history of life-cycle analysis of an automobile fender.

Product design greatly influences the recycling and reuse of manufacturing materials. This article presents a design for recycling strategy based on ease of disassembly, minimizing process scrap, using readily recyclable materials, and labelling or otherwise identifying parts. It also discusses the concept of life-cycle analysis (LCA), a quantitative accounting of the environmental and economic costs of using a given material and the energy required to make, distribute, operate, and eventually dispose of the host product and its constituent materials. An important but often overlooked step in the LCA process is to identify potential improvement pathways.

This article provides an overview of cost analysis in materials selection. It discusses the several categories of alternatives for cost analysis. These include rules of thumb, accounting methods, and analytical methods. The article describes the methods for evaluating materials alternatives on the basis of both direct economic costs and indirect social costs. It considers the life cycle costs of alternative body-in-white designs and life cycle analysis. The various elements of cost are introduced with a case study concerned with the manufacture, use, and disposal of the automobile body-in-white.

Value analysis (VA) is a team problem-solving process to improve the value of a product from the viewpoint of a user. This article presents a comparison between VA and total quality management in materials selection and design. It discusses the key attributes, concepts, and activities of the VA. The application of value engineering in U.S. government contracts and the construction industry is reviewed. The article describes the eight phases of the VA process: preparation, information, analysis, creation, synthesis, development, presentation and report, and implementation and follow-up. It presents case studies that illustrate the materials-related aspects of the VA process.

This article describes the relationship between failure analysis and materials selection and a basic procedure for performing a failure analysis. It discusses the methods for analyzing failures to improve materials selection and presents examples that illustrate the use of failure analysis in materials selection and materials development/refinement.

The basic quality analysis tools are cause-and-effect diagrams, check sheets, control charts, histograms, Pareto charts, scatter diagrams, and run charts. This article reviews how basic quality analysis tools are built upon to become a more advanced set of quality tools. It describes the advanced quality tools: advanced product quality planning, failure mode and effects analysis, control planning, measurement systems analysis, lean tools, statistical process control, production viability and tryout, and Six Sigma.

This article provides an overview of the studies on computational modeling of the vacuum arc remelting (VAR) and electroslag remelting (ESR) processes. These models involve the axisymmetric analysis of the electromagnetic, flow, heat-transfer, and phase-change phenomena to predict the pool shape and thermal history of an ingot using two-dimensional axisymmetric models for VAR and ESR. Analysis of segregation of alloying elements during solidification that gives rise to macrolevel compositional nonuniformity in titanium alloy ingots is also described. The article discusses the important features of the control-volume-based computational method to review the unique aspects of the processes. Measurement of the properties of alloys and slags is explained and an analysis of the process variants for improving the predictive accuracy of the models is presented.

This article presents the importance of progressing from post-manufacturing inspection/verification to in-process inspection/verification methods. It lists the various quality assurance factors considered for typical composite laminate lay-up process. The article provides information on composite cure tooling that is fabricated from steel, aluminum, or high-temperature composite materials. The quality assurance for commercial applications is reviewed. The article concludes with a discussion on data fusion systems designed to provide nondestructive analysis data from fabrication and assembly processes for each individual composite part.

Scanning electron microscopy (SEM) has shown various significant improvements since it first became available in 1965. These improvements include enhanced resolution, dependability, ease of operation, and reduction in size and cost. This article provides a detailed account of the instrumentation and principles of SEM, broadly explaining its capabilities in resolution and depth of field imaging. It describes three additional functions of SEM, including the use of channeling patterns to evaluate the crystallographic orientation of micron-sized regions; use of backscattered detectors to reveal grain boundaries on unetched samples and domain boundaries in ferromagnetic alloys; and the use of voltage contrast, electron beam-induced currents, and cathodoluminescence for the characterization and failure analysis of semiconductor devices. The article compares the features of SEM with that of scanning Auger microscopes, and lists the applications and limitations of SEM.

Concurrent engineering is product development that is done by concurrently utilizing all of the relevant information in making each decision. This article discusses the three aspects that must be taken into account for all product development decisions. The aspects include product functionality, production capability, and field-support capability. The concurrent process is carried out by a multifunctional team that integrates the specialties. The article schematically illustrates product design team configurations with subsystem teams and team of subsystem leaders. It discusses the three-step decision-making process, such as requirements, concepts, and improvement, followed by multifunctional product development teams. The article describes the two types of requirements development by multifunctional teams, namely, quality function deployment and functional analysis. It schematically illustrates the integration of product requirements and concept development. The article concludes with a discussion on the improvement of concepts in terms of robust design and mistake minimization.

Composite materials offer amazing opportunities for delivering structures that are optimized to meet design requirements. This article provides a summary of the concepts discussed in the articles under the section “Engineering Mechanics, Analysis, and Design” in ASM Handbook, Volume 21: Composites. The section introduces many of the engineering approaches used in composite industry.

This article briefly describes the capabilities of gas chromatography/mass spectrometry, which is used to qualitatively and quantitatively determine organic (and some inorganic) compound purity and stability and to identify components in a mixture. The discussion covers in more detail gas chromatography/mass spectrometry (GC/MS) instrumentation, interpreting mass spectra, GC/MS methodology, and GC/MS advances. Sample preparation, which is very important in GC/MS to avoid erroneous data and to minimize maintenance and troubleshooting of the instrument, is also discussed. Further, the article highlights the state of the art in the MS detector technology.

The objective of dimensional management is to create a design and process that absorbs as much variation as possible without affecting the function of the product. This article describes the steps followed by the dimensional management process. These include defining product dimensional requirements, determining process and product requirements, ensuring accurate documentation, developing a measurement plan that validates product requirements, establishing manufacturing capabilities versus design intent, and establishing production-to-design feedback loop. The article discusses the simulation model in terms of a functional feature product model, component part variation, assembly method variation, measurement schemes, and assembly sequences.

This article provides a general introduction of materials characterization and describes the principles and applications of a limited number of techniques that are most commonly used to characterize the composition and structure of metals used in engineering systems. It briefly describes the classification of materials characterization methods including, bulk elemental characterization, bulk structural characterization, microstructural characterization, and surface characterization. Further, the article reviews the selection of materials characterization methods most commonly used with metals.

Integrated computational materials engineering refers to the use of computer simulations that integrate mathematical models of complex metallurgical processes with computer models used in component and process design. This article outlines an example of a computer-aided engineering tool, such as virtual aluminum castings (VAC), developed and implemented for quickly developing durable cast aluminum power train components. It describes the procedures for the model development of the VAC system. These procedures include linking the manufacturing process to microstructure, linking microstructures to mechanical properties, linking material properties to performance prediction, and model validation and integration into the engineering process. The article discusses the benefits of the VAC system in process selection, process optimization, and improving the component design criteria.

Product design for manufacture and assembly can be the key to high productivity in all manufacturing industries. This article discusses the use of design for manufacture and assembly (DFMA) software in the evaluation of proposed designs. It summarizes the steps taken when using DFMA software during design. The article describes the use of design for analysis tool in reducing the number of separate parts, estimating assembly time, and determining design efficiency. It reviews assembly analysis methods such as the assemblability evaluation method, the assembly-oriented product design method, the Lucas method, and the design-for-assembly cost effectiveness method. The article explains the design for manufacture in terms of cost estimation and principal cost drivers. It provides information on the applications of DFMA and roadblocks in the implementation of DFMA. The article concludes with a discussion on the design for automatic assembly.

This article discusses several purposes and types of materials characterization techniques. Some of the factors to be considered when selecting appropriate characterization methods are described. The article also presents the scope and organization of this volume.