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 discusses the conceptual and configuration design of special-purpose parts that are designed and manufactured especially for use in a particular application. It provides a discussion on the issues considered in designing of parts, including, functionality; the relationship of the part to the whole assembly or subassembly; material and process selection; configuration; and tolerances. The article discusses the qualitative physical reasoning and qualitative reasoning that assist in developing part configuration alternatives.

The design process for ceramic materials is more complex than that of metals because of low-strain tolerance, low fracture toughness and brittleness. The application of structural ceramics to engineering systems hinges on the functional benefits to be derived and is manifested in the conceptual design for acceptable reliability. This article discusses the design considerations for the use of structural ceramics for engineering applications. It describes the conceptual design and deals with fast fracture reliability, lifetime reliability, joints, attachments, interfaces, and thermal shock in detailed design procedure. The article provides information on the proof testing of ceramics, and presents a short note on public domain software that helps determine the reliability of a loaded ceramic component. The article concludes with several design scenarios for gas turbine components, turbine wheels, ceramic valves, and sliding parts.

This article presents an overview of an engineering design process. Though the process is extremely complex, distinct stages of design activities are identified and described. The article illustrates guided iteration methodology that helps in problem solving in design. It describes the engineering conceptual design and configuration design of special-purpose parts. It discusses the parametric design methods of the parts and best practices that are used by successful firms to achieve the goals of quality, cost, time-to-market, and marketing flexibility.

This article provides assistance to a failure analyst in broadening the initial scope of the investigation of a physical engineering failure in order to identify the root cause of a problem. The engineering design process, including task clarification, conceptual design, embodiment design, and detail design, is reviewed. The article discusses the design process at the personal and project levels but takes into consideration the effects of some higher level influences and interfaces often found to contribute to engineering failures.

Maintainability is a function of the durability, damage tolerance, and repairability of a structure. This article discusses the configurations of composite structures, such as sandwich, stiffened-skin, and monolithic structures, used in commercial aircraft composites. It describes the considerations for maintainability of the composite structures during the conceptual design phase. Sources of the defects and damage, such as manufacturing defects and in-service defects, are reviewed. The article describes the nondestructive inspection methods that are used in the repair of composite structures to locate damage, characterize the extent of damage, and ensure post-repair quality. It lists suggestions that can be used as design guidelines for adhesive bonding, general composite structure, sandwich structure, material selection, and lightning-strike protection. The article also provides the basic considerations for personnel, facilities, and equipment during maintenance.

Materials selection is closely related to the objectives of failure analysis and prevention. This article briefly reviews the general aspects of materials selection as a concern in both proactive failure prevention during design and as a possible root cause of failed parts. Coverage is more conceptual, with general discussions on the following topics: design and failure prevention, materials selection in design, materials selection for failure prevention, and materials selection and failure analysis. Because materials selection is just one part of the design process, the overall concept of design is discussed. The article also describes the role of the materials engineer in the design and materials selection process. It provides information on the significance of materials selection in both the prevention and analysis of failures.

The intent of this article is to assist the failure analyst in understanding the underlying engineering design process embodied in a failed component or system. It begins with a description of the mode of failure. This is followed by a section providing information on the root cause of failure. Next, the article discusses the steps involved in the engineering design process and explains the importance of considering the engineering design process. Information on failure modes and effects analysis is also provided. The article ends with a discussion on the consequence of management actions on failures.

Materials selection is an important engineering function in both the design and failure analysis of components. This article briefly reviews the general aspects of materials selection as a concern in proactive failure prevention during design and as a possible root cause of failed parts. It discusses the overall concept of design and describes the role of the materials engineer in the design and materials selection process. The article highlights the significance of materials selection in both the prevention and analysis of failures.

This article describes the process of materials selection in relation to the design process, such as materials selection for a new design and materials substitution for an existing design. It reviews the performance characteristics of materials using prototype tests or field tests to determine their performance under actual service conditions. The article describes the selection of a material in relation to the manufacturing process and presents the factors that influence materials selection based on costs and related aspects. These factors include metallurgical requirements, dimensions, processing, quantity, packing, marking, and loading. The article discusses how the needs for materials data evolve as a design proceeds from conceptual to detail design. It describes the methods of materials selection, namely, cost per unit property method, weighted property index method, and limits on properties method.

Engineering design should result in a product that performs its function efficiently and economically within the prevailing legal, social, safety, and reliability requirements. This introductory article discusses some key considerations in design, material selection, and manufacturing that a materials engineer should take into account to satisfy such requirements. It includes a brief section on concurrent engineering, which companies use to ensure that all needed input is obtained and addressed concurrently throughout the product lifecycle, including material selection and processing, product design, cost analysis, manufacturing, recyclability, and performance.

This article discusses the various roles and responsibilities of materials engineers in a product realization organization and suggests different ways in which materials engineers may benefit their organization. It also provides a summary of the concepts discussed in the articles under the Section “The Role of the Materials Engineer in Design” in ASM Handbook, Volume 20: Materials Selection and Design.

Aluminum wrought products, castings, welds, and fasteners are used in many structural applications where they are required to safely support a load. It is useful to design aluminum structural components with its structural properties in mind from conceptualization rather than attempting to mimic components of other materials. This article discusses design specifications, design requirements and methods, and material properties used in aluminum structural design. These properties include tensile yield strength and tensile ultimate strength, welding, and ductility. The article describes various factors that affect the strength of two categories of aluminum structural components, namely members and connections. Design requirements for aluminum bolts, rivets, screws, and pins are provided. The article concludes with a discussion on the considerations for serviceability, namely deflections and vibrations.

As with most engineering materials, the failure of composite materials, no matter how complex, can be divided into three discrete arenas: improper design, improper manufacturing, and improper use of the end product. This article reviews the failure causes from a broad perspective, so that the composites designer, manufacturer, and user can readily see some of the more common issues associated with unique materials. It discusses the three discrete arenas of failure of composite materials: improper design, improper manufacturing, and improper use of the end product.

This article discusses corrosion fatigue, its effects on the damage tolerance of aircraft, and its predictive modeling. A conceptual framework is presented that incorporates two distinctive cyclic-based life-prediction philosophies and expands them both to include the time domain in order to consider the effects of corrosion. These philosophies include crack initiation used for safe-life design and crack growth used for damage tolerance. The article presents the methodology for computing the effects of real-time age degradation on an aircraft structure for two different corrosion types: crevice and pitting corrosion. It describes the rationale and techniques needed to apply the age-based structural integrity processes to in-service structures in order to realize the benefits throughout the full structural life cycle.