Search Results for design allowables

This article discusses the need for design allowables, development of design allowables, and important factors that affect the selection of the allowable. It provides a comparison between lamina and laminate allowables. The article discusses laminate results and specific techniques used in the statistical development of allowable values.

Statistical analysis of mechanical property data is the most reliable method for determination of minimum design allowables. This article describes the general procedures used to determine design allowables. It provides information on the determination of a distribution form. The article presents statistical methods which help in determining design allowables. These methods include direct computation for normal distribution, direct computation for an unknown distribution, computation of derived properties, and regression analysis. The article concludes with information on low- and elevated-temperature design properties.

Detailed analyses and test correlations are typically required to support design development, structural sizing, and certification. This article addresses issues concerning building block levels ranging from design-allowables coupons up through subcomponents, as these levels exhibit a wide variety of test-analysis correlation objectives. At these levels, enhanced analysis capability can be used most effectively in minimizing test complexity and cost while also reducing design weight and risk. The article discusses the examples of tests for which good correlative capability has shown significant benefit. These include notched (open and/or filled hole) tension and compression, inter/intralaminar shear and tension, and pin bearing.

This article discusses composites for unmanned space vehicles and provides an overview of key design drivers, challenges, and environment for use of composites in spacecraft, launch vehicles, and missiles. It describes the design allowable properties of composite materials. The article provides information on the specific state-of-the-art applications of composite materials for spacecraft missiles and launch vehicles. A discussion on the key applications, including solid rocket motor casings, payload fairings, and payload support structures, is presented.

Alloy 2519 is an Al-Cu alloy that was developed as a higher strength weldable alloy for armor plate. This datasheet provides information on key alloy metallurgy of alloy 2519 and processing effects on mechanical properties of 2519-T87 plate.

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 describes common design criteria and identifies the design considerations that have a significant effect on the end product. The design criteria include cost, size, mechanical properties, repeatability and precision of parts, damage tolerance and durability, and environmental constraints.

This article addresses the issue of the implementation of composite damage tolerance requirements as it relates to military aircraft. It presents a brief introduction on the durability impact threat, damage tolerance impact threat, and other damage tolerance damage threats. The article summarizes damage tolerance criteria and durability criteria for military aircraft. It discusses the damage tolerance design philosophy for metallic structures and composite structures of the aircraft. The article describes the implementation of a damage tolerance analysis methodology in terms of the mechanics based model, the regression algorithm, and the semi-empirical analysis.

This article discusses three typical repair types for composite structures: temporary repairs, adhesively bonded repairs, and bolted repairs. It contains a table that lists general design requirements and considerations for the repair of composite structures. The article describes ten steps for an engineering repair approach to effectively restore structural integrity to damaged composite components. Management, validation and certification of repairs are also discussed. The article presents the design guidelines for analyzing the damage and possible strategies for making a repair. It reviews three repair schemes used in repair design analysis, namely, core replacement, adhesively bonded patch, and mechanically fastened patch. The article also emphasizes the various pitfalls and problems in repair design for composite structures.

This article discusses some of the factors that are linked directly to the casting design of ductile iron castings. It reviews the choice of molding process, application of draft, and patternmaker's allowance that should be taken into consideration in designing castings. The article describes the solidification shrinkage associated with the volume change that occurs during solidification, as well as strength and stiffness of ductile iron castings. It concludes with a discussion on the thermal deformation and residual stress in ductile iron castings.

Composites are complex engineered materials that often behave differently than common isotropic materials. Before testing a composite material, or before ordering or supervising such testing, the responsible party should review certain considerations. This article provides an overview of such considerations, namely, the differences between the testing of composites and testing of isotropic materials, role of certification agencies and importance of their involvement, building-block approach to composites testing, determining the purpose of testing, normalizing results, and statistical data reduction.

Alloy 2055 is an Al-Cu-Li alloy developed as a replacement for high-strength 7xxx and 2xxx alloys in applications such as fuselage stringers and floor beams. This datasheet provides information on its key alloy metallurgy and illustrates the damage tolerance of 2055-T84 extrusions and 7xxx extrusions.