Search Results for stress R-curves

Alloy 2624 was developed by Alcoa as a plate product to replace alloy 2024 and 2324 in applications requiring moderate or high strength and the highest levels of damage tolerance. This datasheet provides information on composition limits, processing effects on physical and mechanical properties, and applications of this alloy. Figures provide comparisons of plane stress R-curves of 2624 with 2024-T351 and 2324-T39 and fatigue crack growth resistance of 2624 with 2024-T351 and 2324-T39.

This datasheet provides information on key alloy metallurgy and applications of Alclad 2029. It contains tables that present statistically determined mechanical property minimums for Alclad 2029-T8 sheet and plate. The plane stress fracture toughness and fatigue crack growth resistance of alloys 2029 and 2024 are illustrated.

Optimized modeling of fracture-critical structural components and connections requires the application of elastic-plastic fracture mechanics. Such applications, however, can require sophisticated analytical techniques such as crack tip opening displacement (CTOD), failure assessment diagram (FAD), and deformation plasticity failure assessment diagram (DPFAD). This article presents the origin and description of FAD and addresses R6 FAD using J-integral. It details the fracture criteria of BS 7910. The factors to be considered during the use of FAD and the applications of FAD are also reviewed.

In the design of composite structures for durability and damage tolerance, the primary concerns are out-of-plane failures, such as delamination, material degradation associated with environment, stability under compression loading, large degree of scatter in fatigue life, and bearing failure of joints. This article presents an introductory discussion on the fatigue damage process, methodologies assessing fatigue behavior, and life prediction models. It describes the damage mechanisms introduced for a quasi-isotropic laminate under tension-compression fatigue loading. Delamination is a critical issue in fatigue and generally results from high interlaminar normal and shear stresses. The article schematically illustrates the structural elements in which high interlaminar stresses are common. It concludes with a discussion on the classification of fatigue models such as mechanistic or phenomenological, for composite materials under cyclic loading.

Catastrophic failure best typifies the characteristic behavior of brittle solids in the presence of cracks or crack-like flaws under ambient conditions. This article provides a description of the concepts of fracture mechanics of brittle solids and focuses on the various testing methods developed to characterize the fracture behavior of brittle solids with examples. These include the fracture toughness test method and R-curve test method at ambient and elevated temperatures. The article also includes information on the evaluation of fracture-toughness test results and the behavior of R-curve.

This article focuses on mechanical behavior of materials under conditions of uniaxial tension and compression. The emphasis is on mechanical behavior during the engineering tension test, which is used to provide basic design information on the strength of materials and as an acceptance test for the specification of materials. The article presents mathematical expressions for a flow curve of many metals in the region of uniform plastic deformation. It explains that the rate at which strain is applied to the tension specimen has an important influence on the stress-strain curve. The point of necking at maximum load can be obtained from the true stress-true strain curve by finding the point on the curve having a subtangent of unity. The article concludes with an overview of the ductility measurements performed by notch tensile and compression tests.

This article introduces the concepts of linear-elastic fracture mechanics (LEFM) and elastic-plastic fracture mechanics (EPFM). It reviews the fracture mechanics of ceramics and ceramic matrix composites (CMCs). The article describes some fracture toughness measurement techniques used on ceramics and CMCs: single edge notch bending, compact tension, double cantilever beam testing, chevron notch methods, and double torsion. It presents descriptions organized by their specimen types, and includes the advantages and disadvantages, as well as the experimental control schemes employed for each specimen type.