Search Results for full factorial design

This article presents an approach to manage the uncertainty present in materials design. It describes inductive and deductive approaches to deal with uncertainty. The article focuses on providing an understanding of the opportunities for managing uncertainty and the decisions that influence the accuracy of the results. A design of experiments (DOE) represents a sequence of experiments to be performed, expressed in terms of factors set at specified levels. The article discusses the two types of DOEs: the full factorial design and the fractional factorial design. It explains the factors to be considered when selecting a procedure for propagating uncertainty. The article lists the categories of the popular types of uncertainty propagation methods, including simulation-based methods, local expansion methods, and numerical integration-based methods.

Process optimization is the discipline of adjusting a process to optimize a specified set of parameters without violating engineering constraints. This article reviews data-driven optimization methods based on genetic algorithms and stochastic models and demonstrates their use in powder-bed fusion and directed energy deposition processes. In the latter case, closed-loop feedback is used to control melt pool temperature and cooling rate in order to achieve desired microstructure.

The most effective design teams generally involve a clearly delineated group of individuals who work full time on the specified project from its beginning until market introduction. This article focuses on issues arising in using teams in a product design process. It provides special coverage on alternative roles for specialists, such as materials engineers or scientists, whose expertise is essential to the success of the project. The article discusses the types of teams exhibiting certain characteristics in the sales, accounting, and research departments and from the factory floor to the executive suite. The special characteristics of cross-functional development teams are discussed. The article reviews the staffing of a development team, including team leader, team members, and suppliers on the team. It describes the considerations for organizing a development team, and the role of development team specialists on balancing team needs.

When planning a corrosion-testing program, it is advisable to select the testing conditions carefully in order to produce ranking parameters with minimal influence from testing conditions while rich in engineering significance. This article provides a discussion on test objectives, metal composition and metallurgical conditions, test specimen preparation, and corrosion damage assessment. It describes a strategy for planning the design of controlled and uncontrolled factorial experiments. The article contains a table that lists the elements of an iterative process for the experimental design. It illustrates the experimental designs applied to corrosion testing.

Planning of experiments does not consist merely of identifying a few key parameters and then selecting a specific plan. Selection of the proper experimental plan depends on the purpose of the experiment, physical restrictions on the taking of measurements, and other restrictions imposed by time, economic considerations, and materials and personnel availability. This article presents recommendations that should be followed in outlining the methods of conducting and analyzing an experiment to ensure successful results. It discusses restricted type of experiments, in which the experimenter varies the parameters, or factors, under study and then observes the effects of this action. These include factorial experiments, blocked factorial experiments, and fractional factorial experiments. The article describes the estimation of experimental errors and provides information on randomized designs and block designs. It also presents the methods for determining optimum conditions or levels.

This article describes methods that are oriented toward the analysis of planned cooperative experiments that involve multiple factors, blocks, and/or treatment levels. The experiments include factorial, fractional factorial, randomized block, and incomplete block experiments.

Statistics are extremely important tools in the operation of press shops, providing numerical process analysis capabilities. The most common use of statistics in the press shop is statistical process control (SPC) that uses statistical techniques such as control charts to analyze a process or its output to enable appropriate actions to be taken to achieve and maintain a state of statistical control. This article discusses the role of statistics in sheet metal forming operations, both in terms of SPC techniques, such as control charting, statistical deformation control, and experimental design, including single-variable studies, multivariable studies, and Taguchi experiments.

Thermomechanical are used to gain insight into the causes of problems that arise during a given thermomechanical process. This article provides examples to demonstrate how significant the parameters were selected for specific tests. It examines the types of problems that can occur during a thermomechanical process. The article provides information on the thermophysical properties, which include specific heat, coefficient of thermal expansion, thermal conductivity/diffusivity, and density. It concludes with examples that illustrate how the various considerations in testing are successfully used to solve practical thermomechanical processing problems.

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 describes the basic functions that should be included when considering the relationship of computer-aided design (CAD)/computer-aided manufacturing (CAM) and machining. These include design, analysis, drafting, process planning, part programming, program verification, part machining, and inspection. The article provides information on hardware, data base, interfaces, and benefits of integrating machining with the CAD/CAM system of a manufacturing plant. It also provides an overview of direct, computer and, distributed numerical control, which are devoid of a number of problems inherent in conventional numerical control.

Reliability is a measure of the capacity of equipment or systems to operate without failure in the service environment. This article focuses on reliability in design and presents equations governing the instantaneous failure rate, general reliability function, mean time to failure, mean time between failures, and useful life period. The article describes the calculation of reliabilities for series and parallel arrangements of a complex system. It provides a comparison of probabilistic and deterministic design and concludes with a discussion on reliability growth.

This article presents the benefits of selecting plastics for products to be manufactured. It discusses the four key considerations for plastic part design: material, process, tooling, and design. The article provides a detailed discussion of the development sequence for plastic parts. The basis for the development sequence is twofold: first, to create the best solution for the application, and second, to minimize potential project risks through careful and thoughtful work habits.

This article provides an outline of the issues to consider in performing a probabilistic life assessment. It begins with an historical background and introduces the most common methods. The article then describes those methods covering subjects such as the required random variable definitions, how uncertainty is quantified, and input for the associated random variables, as well as the characterization of the response uncertainty. Next, it focuses on specific and generic uncertainty propagation techniques: first- and second-order reliability methods, the response surface method, and the most frequently used simulation methods, standard Monte Carlo sampling, Latin hypercube sampling, and discrete probability distribution sampling. Further, the article discusses methods developed to analyze the results of probabilistic methods and covers the use of epistemic and aleatory sampling as well as several statistical techniques. Finally, it illustrates some of the techniques with application problems for which probabilistic analysis is an essential element.

This article provides a brief description of load conditions for single-shot heat treating, vertical scanning, and brazing and soldering. It discusses the various power components used in power supplies. These include capacitors, integrated power module, transformers, and various switching devices, namely, silicon-controlled rectifiers, insulated-gate bipolar transistors, and metal-oxide semiconductor field-effect transistors. The article also provides information on frequency-multiplication harmonic-induction power supplies, namely, push-pull and half-bridge inverters and full-bridge inverters. Series resonant and parallel resonant circuits and their tuning calculations associated with output networks are also discussed. The article describes the frequency range of simultaneous dual-frequency induction heating power supply, and discusses the advantages, applications, and technical background of independently controlled frequency and power (IFP) induction heating power supply. It concludes with a description of the developments in control systems for modern induction power supplies.

Composites, particularly fiber-reinforced polymer materials, are increasingly being adopted or considered as alternatives to conventional materials for civil infrastructure applications, such as bridges, buildings, waterfront structures, waste treatment facilities, and facilities for transmission and transport of utilities. This article provides information on seismic retrofit applications and discusses the repair and strengthening of components, such as beams, slabs, large-diameter pipes, and bridge decks.

Press brakes are a common and versatile type of equipment for bending metal by delivering an accurate vertical force in a confined longitudinal area. This article begins with a discussion on the design, widening methods, and types of materials used in press brakes. It focuses on the two basic drive systems used in operating press brakes, namely, mechanical and hydraulic drive systems. The article also provides an outline on the tooling associated with press-brakes.

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.

The aviation industry has been driving the use of additive manufacturing (AM), moving from one-off demonstrator or pathfinder components toward higher-volume serial production applications. This article presents an introduction to AM in aviation, explaining how aviation requirements apply to AM. It also presents advancements, standards, and future expectations of aviation.

This article reviews the performance of power electronics components, namely, power rectifiers, insulated-gate bipolar transistors, metal-oxide semiconductor field-effect transistors, diodes, and silicon-controlled rectifiers. It provides information on induction heating power supplies with multiple heat stations, such as switching units and multiple (zone) outputs. The article describes power supply operational control and power supply protection circuits. It details duty cycle, power factor, and harmonics of power supplies. The article also describes system parameters, software analysis-calculations, human analysis-decisions, multiple system arrangements, and zone control systems for power supply selection. It provides information on the maintenance of induction power supplies, detailing the safety precautions to be taken and the need for routine inspection and servicing.