This article reviews the dynamic factors, experimental methods and setup, and result analysis of different types of high strain rate shear tests. These include high strain rate torsion testing, double-notch shear testing and punch loading, drop-weight compression shear testing, thick-walled cylinder testing, and pressure-shear plate impact testing.

Powder metallurgy (PM) high-alloy tool steels (HATS) have unique properties that assist them in solving various problems related to machining of metal components. This article describes the cost-intensive PM processing routes of HATS, as well as their major properties, including elastic properties, density, mechanical properties, grindability, fatigue and wear resistance, and thermophysical properties.

Braiding is a textile process that is known for its simplicity and versatility. Braided structures are unique in their high level of conformability, torsional stability, and damage resistance. This article describes the braiding process and the mechanical properties of two-dimensional and three-dimensional braiding.

This article reviews the essential parts of the complex process of quantitative image analysis to assist automatic image analysis in laboratories. It describes the basic difference between the bias of classical manual stereological analysis and quantitative image analysis. The article concentrates on the basic properties of digital measurements that are the core of quantitative image analysis. It provides a brief description of the specimen and apparatus preparation as well as the image acquisition. The article explains how to evaluate stereological parameters and provides the general rules and guidelines for optimization of image processing algorithms from the viewpoint of shape quantification. It concludes with examples that demonstrate the usefulness of automatic image analysis in comparison to manual methods.

This article presents the damage tolerance criteria for military composite aircraft structures to safely operate the structures with initial defects or in-service damage. It describes the effects of defects, such as wrinkles in aircraft structures, and the reduction in compressive strength and tensile strength. The article reviews low velocity impacts in aircraft structures in terms of resin toughness, laminate thickness, specimen size and impactor mass, and post-impact fatigue. It explains the tension strength analysis, such as linear elastic fracture mechanics and R-curve methods, to predict the residual strength of the structures.

High strain rate testing is important for many engineering structural applications and metalworking operations. This article describes various methods for high strain rate testing. Several methods have been developed, starting with the pioneering work of John Hopkinson and his son, Bertram Hopkinson. Based on these contributions and also on an important paper by R.M. Davies, H. Kolsky invented the split-Hopkinson pressure bar, which allows the deformation of a sample of a ductile material at a high strain rate, while maintaining a uniform uniaxial state of stress within the sample.

This article describes the techniques involved in measuring the high-strain-rate stress-strain response of materials using a split-Hopkinson pressure bar (SHPB). It focuses on the generalized techniques applicable to all SHPBs, whether compressive, tensile, or torsion. The article discusses the methods of collecting and analyzing compressive high-rate mechanical property data. A review of the critical experimental variables that must be controlled to yield valid and reproducible high-strain-rate stress-strain data is also included. Comparisons and contrasts to the differences invoked when using a tensile Hopkinson bar in terms of loading technique, sample design, and stress-state stability, are discussed.

This article discusses many of the processes and related considerations involved in the forming of superplastic sheet metal parts. It reviews the requirements for superplasticity and describes the characteristics of superplastic metals. The characterization of superplastic behavior includes the characterization of plastic flow, internal cavitation, and fracture behavior. Processing variables needed for the overall characterization of superplastic behavior are summarized. The article discusses the superplastic forming methods, namely, blow forming, vacuum forming, thermoforming, deep drawing, superplastic forming/diffusion bonding, forging, extrusion, and dieless drawing. It provides information on superelastic forming equipment and tooling. The article explains the thinning characteristics and quick plastic forming and its technological elements. It describes the manufacturing practice of the process. The article concludes with a discussion on the superplastic behavior in iron-base alloys.

Advanced thermoplastic composites possess impact resistance, fracture toughness, and elevated temperature endurance properties due to their melt-fusible nature. This article presents the material options available for thermoplastic composites such as pseudothermoplastics, post-impregnated thermoplastics, and true thermoplastics. It describes the processing methods of thermoplastic composites, including weaving, seaming, autoclaving, preconsolidation, roll consolidation, roll forming/pultruding, thermoforming, press forming, hydroforming, and diaphragm forming. The article provides information on different types of joints, namely, fastened, adhesive bonded, dual polymer bonded, co-consolidated, and welded joints. It explains the joining methods of thermoplastic composites, such as press forming, diaphragm forming, autoclaving, ultrasonic welding, resistance welding, and induction welding.

This article presents a detailed account of directed-energy deposition (DED) processes that are used for additive manufacturing (AM) of metallic materials. It begins with a process overview and a description of the components of DED systems followed by sections providing information on the process involved in DED and the materials used for DED. The postprocessing applied to the material after deposition is then covered. The article discusses the properties of metallic materials produced by using DED and ends with a discussion on applications for DED processes in various industries.

This article focuses on the factors to be considered for selecting fasteners for joining carbon fiber composites. These considerations include corrosion compatibility, fastener materials, strength, stiffness, head configurations, importance of clamp-up, hole fit, and lightning protection.

This article reviews high strain rate compression and tension test methods with a focus on the general principles, advantages, and limitations of each test method. The compression test methods are cam plastometer test, drop tower compression test, the Hopkinson bar in compression, and rod impact (Taylor) test. The flyer plate impact test, expanding ring test, split-Hopkinson bar in tension, and a test using a rotating wheel used for high strain rate tension are also discussed.

This article briefly reviews the general causes of weldment failures, which may arise from rejection after inspection or failure to pass mechanical testing as well as loss of function in service. It focuses on the general discontinuities observed in welds, and shows how some imperfections may be tolerable and how the other may be root-cause defects in service failures. The article explains the effects of joint design on weldment integrity. It outlines the origins of failure associated with the inherent discontinuity of welds and the imperfections that might be introduced from arc welding processes. The article also describes failure origins in other welding processes, such as electroslag welds, electrogas welds, flash welds, upset butt welds, flash welds, electron and laser beam weld, and high-frequency induction welds.

Simulation programs are becoming more effective tools in reducing the need for physical testing and the avoidance of costly downstream problems by solving the problems upfront in the early development stage. This article provides a brief review of the history and applied analysis of simple forming operations. It focuses on metal stamping simulation based on the finite-element methods or model (FEM) with emphasis on software tools using the three-dimensional FEM technology. The article discusses two aspects of particular importance in finite-element analysis of sheet forming and springback analysis: the type of solution algorithm/governing equation and the type of element. The article provides information on various models for material yield criteria.

This article is a compilation of definitions of the terms related to sheet metal forming and fabrication.

Springback refers to the elastically driven change of shape that occurs after deforming a body and then releasing it. This article presents an introduction to the concepts of springback simulation as well as recommendations for its practice in a metal forming setting of thin beams or sheets. It discusses bending with tension and more complex numerical treatments. The article addresses the limitations of the various assumptions followed in springback simulation. It provides a discussion on the design of dies and tooling using an assumed springback prediction capability.

This article focuses on a variety of laser beam machining (LBM) operations of aluminum and its alloys, namely, laser cutting, laser drilling, laser milling, laser turning, laser grooving, laser scribing, laser marking, and laser micromachining. It presents different approaches for carrying out machining operations, laser processing parameters, efficiency and accuracy of the process, and the effect of laser processing parameters on the quality of the machined surface. The article provides an overview of the various conventional (chip forming) and nonconventional machining techniques employed for aluminum-based materials. A comparison of the various aspects of LBM with other non-conventional techniques is also presented. The article also describes the features of LBM techniques employed for aluminum and its alloys for different types of machining.