Search Results for functional analysis

The diffraction pattern of any material contains structural and chemical property information that can be extracted using radial distribution function analysis. This article provides an introduction to the technique and presents several examples highlighting various ways in which it can be used. It begins with a discussion on the principles of diffraction and scattering and the effectiveness of x-ray, neutron, and electron energy sources for different types of measurements. It provides information on data collection and reduction and explains how to create atomic distribution plots from intensity and scattering angle data. The article also presents application parameters for defining short distances and background intensity and describes a procedure for generating pair distribution functions.

This article discusses the major methods of elemental analysis, namely, the combustion method for carbon, hydrogen, and nitrogen; the Kjeldahl method for nitrogen; and the Schoniger flask method for other common elements. It also discusses the methods of functional group analysis for acids, alcohols, aldehydes and ketones, amines, esters, aromatic hydrocarbons, peroxides, phenols, water (Karl Fischer method), and alkenes.

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.

This article provides a brief introduction to neutron diffraction as well as its state-of-the-art capabilities. The discussion covers the general principles of the neutron, neutron-scattering theory, generation of neutrons, types of incident radiation, and purposes of single-crystal neutron diffraction, powder diffraction, and pair distribution function analysis. The relationship between detector space and reciprocal space are presented. Various factors involved in sample preparation, calibration, and techniques used for analyzing diffraction data are described. The article also presents application examples and possible future developments in neutron diffraction.

This article focuses on two streams of the research on part consolidation (PC): PC in the conventional manufacturing context, and PC in the additive manufacturing (AM) context. It reviews the challenges of applying AM-PC potentials. The article includes research literature on the selection of part candidates for consolidation and summarizes the conversion of assembly design to consolidated design. Then, a holistic approach for supporting PC design is introduced with integrated modules of part filtering and fusion of parts. Details of the key techniques of the two modules are later introduced with a gas pedal example. Finally, emerging trends in PC research are discussed.

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.

A concise and quantified specification is essential to developing suitable product concepts. This article describes an integrated set of structured methods for identifying the customer population for the product and developing a representation of feature demands. The structured methods include design task probing, customer needs analysis, functional decomposition, and competitive benchmarking for directly mapping customer statements to functional requirements.

This article describes the methodology for performing a failure modes and effects analysis (FMEA). It explains the methodology with the help of a hot water heater and provides a discussion on the role of FMEA in the design process. The article presents the analysis procedures and shows how proper planning, along with functional, interface, and detailed fault analyses, makes FMEA a process that facilitates the design throughout the product development cycle. It also discusses the use of fault equivalence to reduce the amount of labor required by the analysis. The article shows how fault trees are used to unify the analysis of failure modes caused by design errors, manufacturing and maintenance processes, materials, and so on, and to assess the probability of failure mode occurrence. It concludes with information on some of the approaches to automating the FMEA.

Vibroacoustic analysis of mechanical systems has an important role in the engineering discipline. This can be used as a monitoring tool to obtain insights about the condition of a system, identify its probable defects, and determine the time window that the maintenance should happen. This article introduces the basics of signal processing in time, frequency, and time-frequency domains. It focuses on statistical analysis of the time-domain data. Various measures of data distribution and variability are pointed out. Important signal-processing functions in the frequency domain are presented and explained with examples. The article discusses and clarifies the benefits of time-frequency domain based on short-time Fourier transform with some practical applications. The article presents the most frequently used statistical functions. It concludes with information on some real-world applications of vibroacoustic analysis.

This article describes design factors for products used in engineering applications. The article groups these factors into three categories: functional requirements, analysis of total life cycle, and other major factors. These categories intersect and overlap, constituting a major challenge in engineering design. Performance specifications, risk and hazard analysis, design process, design for manufacture and assembly, design for quality, reliability in design, and redesign are considered for functional requirements. Life-cycle analysis considers raw-material extraction from the earth and product manufacture, use, recycling (including design for recycling), and disposal. The other major factors considered include evaluation of the current state of the art for a given design, designing to codes and standards, and human factors/ergonomics.

Machine vision, also referred to as computer vision or intelligent vision, is a means of simulating the image recognition and analysis capabilities of the human eye and brain system with digital techniques. The machine vision functionality is extremely useful in inspection, supervision, and quality control applications. This article presents a variety of machine vision functions for different purposes and provides a comparison of machine and human vision capabilities in a table. It discusses the processes of a machine vision system: image acquisition, image preprocessing, image analysis, and image interpretation. The article provides information on the uses of machine vision systems in three categories of manufacturing applications: visual inspection, identification of parts, and guidance and control applications.

Solidification of cast iron alloys brings about volumetric changes. This article describes direct measurements of volume changes with an illustration of the analysis of volumetric changes during solidification of cast iron with the use of a specially designed riser combined with a furnace. It provides a discussion on the dilatometer analysis that is generally used to measure linear displacement as a function of temperature for all types of materials, and the problems associated with volume-change measurements. The article presents a graphical representation of a consequence of the anisotropy, where the calculated volume change is illustrated as a function of temperature. It concludes with a review of kinetic of graphite expansion.

This article describes testing and characterization methods of ceramics for chemical analysis, phase analysis, microstructural analysis, macroscopic property characterization, strength and proof testing, thermophysical property testing, and nondestructive evaluation techniques. Chemical analysis is carried out by X-ray fluorescence spectrometry, atomic absorption spectrophotometry, and plasma-emission spectrophotometry. Phase analysis is done by X-ray diffraction, spectroscopic methods, thermal analysis, and quantitative analysis. Techniques used for microstructural analysis include reflected light microscopy using polarized light, scanning electron microscopy, transmission electron microscopy, energy dispersive analysis of X-rays, and wavelength dispersive analysis of X-rays. Macroscopic property characterization involves measurement of porosity, density, and surface area. The article describes testing methods such as room and high-temperature strength test methods, proof testing, fracture toughness measurement, and hardness and wear testing. It also explains methods for determining thermal expansion, thermal conductivity, heat capacity, and emissivity of ceramics and glass and measurement of these properties as a function of temperature.

Failure analysis is a process that is performed in order to determine the causes or factors that have led to an undesired loss of functionality. This article is intended to demonstrate proper approaches to failure analysis work. The goal of the proper approach is to allow the most useful and relevant information to be obtained. The discussion covers the principles and approaches in failure analysis work, objectives and scopes of failure analysis, the planning stages for failure analysis, the preparation of a protocol for a failure analysis, practices used by failure analysts, and procedures of failure analysis.

This article describes the historical background, uncertainties in structural parameters, classifications, and application areas of probabilistic analysis. It provides a discussion on the basic definition of random variables, some common distribution functions used in engineering, selection of a probability distribution, the failure model definition, and a definition of the probability of failure. The article also explains the solution techniques for special cases and general solution techniques, such as first-second-order reliability methods, the advanced mean value method, the response surface method, and Monte Carlo sampling. A brief introduction to importance sampling, time-variant reliability, system reliability, and risk analysis and target reliabilities is also provided. The article examines the various application problems for which probabilistic analysis is an essential element. Examples of the use of probabilistic analysis are presented. The article concludes with an overview of some of the commercially available software programs for performing probabilistic analysis.

Failure analysis is a process that is performed to determine the causes or factors that have led to an undesired loss of functionality. This article describes some of the factors and conditions that might be considered when approaching a failure analysis problem. It focuses on the key principles, objectives, practices, and procedures of failure analysis. The article provides guidelines on the preparation of a protocol for a failure analysis. It also demonstrates the proper approaches to failure analysis.