This article discusses physical analysis, including slab method and upper-bound method and slip-line field analysis, for calculating stress states in plastic deformation processes. It presents various validation standards and models for evaluating the criterion of fracture for use in finite-element analyses of deformation processing. The article reviews the Cockcroft-Latham criterion of fracture and its reformulated extension for analysing the fracture locus for compression. It concludes with information on fundamental fracture models.

This article focuses on approximate closed-form analytical methods, such as slab and upper bound methods, used for forward and inverse design of metal forming problems. Selected examples of application of these methods to metal forming processes are also discussed.

Coextrusion is defined as the simultaneous extrusion of two or more metals to form an integral product that can be carried out using conventional extrusion or drawing equipment at a temperature appropriate to the metal system being formed. This article discusses the applications, billet configurations, and metal flow modes of coextrusion. It presents the analytical studies of coextrusion: deformation energy methods, lower-bound (slab) analyses, upper-bound analyses, and finite-element analyses. These studies are used to identify the regime of material properties and process variables for which sound extrusions can be obtained. The article concludes with a discussion on the state-of-the-art of coextrusion that assists in developing process models, which accurately describe both the macroscopic and microscopic aspects of a process.

This article focuses on the effects of mechanical plasticity on workability; that is, process control of localized stress and strain conditions to enhance workability. It describes the nature of local stress and strain states in bulk forming processes, leading to a classification scheme, including testing procedures and specific process measurements, that facilitate the application of workability concepts. Using examples, the article applies these concepts to forging, rolling, and extrusion processes. The stress and strain environments described in the article suggest that a workability test should be capable of subjecting the material to a variety of surface strain combinations. By providing insights on fracture criteria, these tests can be used as tools for troubleshooting fracture problems in existing processes, as well as in the process development for new product designs.

Workability is the ability of the workpiece metal to undergo extrusion or drawing without fracture or defect development. This article describes the limits of workability in extrusion and drawing in terms of fracture and flaw development and presents some comments on fracture mechanisms. It discusses the empirical projections of absolute workability from various mechanical tests. The article concludes with a discussion on extrusion and drawing process design implications.

This article addresses the effects of damage to equipment and structures due to explosions (blast), fire, and heat as well as the methodologies that are used by investigating teams to assess the damage and remaining life of the equipment. It discusses the steps involved in preliminary data collection and preparation. Before discussing the identification, evaluation, and use of explosion damage indicators, the article describes some of the more common events that are considered in incident investigations. The range of scenarios that can occur during explosions and the characteristics of each are also covered. In addition, the article primarily discusses level 1 and level 2 of fire and heat damage assessment and provides information on level 3 assessment.

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.

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.

Probability of detection (POD) assesses the performance of a non-destructive evaluation (NDE)-based inspection, which is a method used to determine the capability of an inspection as a function of defect type and defect size. This article provides an overview of the concept of POD, why it is needed, the history behind the development of POD, how POD assessments are performed, and how modeling and simulation can be integrated into the execution of a POD assessment. It describes the methods by which POD is determined. This includes detail on the experimental process to acquire the needed data, the mathematical methods to obtain a POD curve, and techniques to assess uncertainty in the POD curve as it is obtained from a limited data set. The concept of model-assisted POD (MAPOD) is introduced, with additional details and representative examples of MAPOD.

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.

This article presents the Schmid's law that describes the response of crystal structures to loading. It describes the Taylor model to calculate the uniaxial yield stress of an isotropic face-centered cubic aggregate in terms of critical resolved shear stress. The article discusses the stress-based approach of the Bishop and Hill procedure to directly find stress states that could simultaneously operate at least five independent slip systems. It presents ways to find isostress or lower-bound yield loci for sheets having single-crystal orientation.

Affordability is the key issue facing design engineers and manufacturers of composite components for current and next-generation aircraft, spacecraft, propulsion systems, and other advanced applications. This article describes the software tools available for modeling and analyzing costs associated with design and manufacturing options for advanced composites programs. It presents an example of a composite exhaust nozzle shroud where the design and manufacture options were analyzed and adjusted, based on the use of cost analysis tools. The article also lists some of the attributes found in various cost modeling software and the potential cost benefits.

This article describes the use of compression tests, namely, cylindrical compression, ring compression, and plane-strain compression tests at elevated temperatures. It discusses the effects of the temperature, strain rate, and deformation heating on metals during the cylindrical compression test, with the help of flow curves. The article illustrates the testing apparatus used in the cylindrical compression test. It describes the issues regarding friction and temperature, and strain-rate control with proper test equipment and experimental planning during the ring compression test and plane-strain compression test. The article also reviews the testing conditions, procedures, and advantages of hot plane-strain compression test.

The primary objectives of the rolling process are to reduce the cross section of the incoming material while improving its properties and to obtain the desired section at the exit from the rolls. This article illustrates a rolling sequence for the fabrication of bars, shapes, and flat products from blooms, billets, and slabs. It describes two methods for shapes or sections: universal rolling and caliber rolling. The article provides information on two-high mills and three-high mills. Specialty mills for thin sheets, namely, the Sendzimir mill and planetary mill, are discussed. The article analyzes the components of a computer controlled system for high-speed mills. Steels and nonferrous materials are also discussed. The article concludes with information on the defects in flat, bar, or shaped products due to heating and rolling practices.