Time-domain based characterization methods, mainly time-domain reflectometry (TDR) and time-domain transmissometry (TDT), have been used to locate faults in twisted cables, telegraph lines, and connectors in the electrical and telecommunication industry. This article provides a brief review of conventional TDR and its application limitations to advanced packages in semiconductor industry. The article introduces electro optical terahertz pulse reflectometry (EOTPR) and discusses how its improvements of using high frequency impulse signal addressed application challenges and quickly made it a well-adopted tool in the industry. The third part of this article introduces a new method which combines impulse signal and the TDT concept, and discusses a combo TDR and TDT method. Cases studies and application notes are shared and discussed for each technique. Application benefits and limitations of these techniques (TDR, EOTPR, and combo TDR/TDT) are summarized and compared.

Several components from the tail boom of a helicopter were found fractured at a crash site, including gusset plates, the hat section near the lower yoke, and a cable that controls the pitch of the tail rotor. The components were recovered from the wreckage and taken to a lab for closer examination. Based on their observations and the results of SEM fractography, failure analysts concluded that the gusset plates failed due to a downward bending overload in tension and that the tail rotor control cable snapped due to tensile overload. There were no indications of delayed failure in any of the areas examined.

Many companies conduct only metallurgical evaluations in the wake of failures, discovering nothing more than the physical mechanism by which the failure occurred. The origin of failures, however, is often complex, involving not only physical mechanisms, but also human behavior and latent factors. Failures may also involve multiple parts, entire machines, or processes of any size and shape. The chapter examines the unique aspects of many failures and explains how they can sometimes be traced to systemic issues. It also covers the reasons why products fail, including improper service or operation, improper maintenance, improper testing, assembly errors, fabrication or manufacturing errors, and design errors. The case of the Tacoma Narrows Bridge collapse is presented to illustrate the consequence of overlooked factors, in this case, wind dynamics, and the importance of identifying root causes to prevent repeat failures.

This chapter describes the mechanical properties of fully pearlitic microstructures and their suitability for wire and rail applications. It begins by describing the ever-increasing demands placed on rail steels and the manufacturing methods that have been developed in response. It then explains how wire drawing, patenting, and the Stelmor process affect microstructure, and describes various fracture mechanisms and how they appear on steel wire fracture surfaces. The chapter concludes by discussing the effects of torsional deformation, delamination, galvanizing, and aging on patented and drawn wires.

The chapter presents an overview of the properties and operational limits of superconductive materials, as well as techniques used to fabricate practical superconducting wires. It introduces six properties: critical temperature, critical magnetic field, critical current density, stability, ac loss, and mechanical characteristics; for each property, typical data are provided and the experimental methods used to measure it are briefly described. The properties of the superconducting composites are tied together in the chapter to summarize their effect on superconductor material selection and the geometrical design of superconducting composites. The chapter also contains a reference guide to composite-design factors with links to the relevant chapter sections where each design consideration is addressed.

This appendix is a compilation of terms and definitions related to composite filament winding.

This chapter discusses the properties and processing characteristics of glass, aramid, carbon, and ultra-high molecular weight polyethylene fibers and related product forms, including woven fabrics, prepreg, and reinforced mats. It also includes a review of fiber terminology as well as physical and mechanical property data for commercially important high-strength fibers.

Coil design for induction heating has been developed and refined over time based on the theoretical principles applied in practice to several simple inductor geometries such as the classical solenoidal coil. This chapter reviews the fundamental considerations in the design of inductors and describes some of the most widely used coils and common design modifications. Specialty coil designs for specific applications are also discussed. The chapter concludes with sections devoted to coil fabrication and design of power-supply leads.

This chapter provides an overview of the possible mechanisms of failure for heat treated steel components and discusses the techniques for examining fractures, ductile and brittle failures, intergranular failure mechanisms, and fatigue. It begins with a description of the general sources of component failure. This is followed by a section on the stages of a failure analysis, which can proceed one after the other or occur at the same time. These stages of analysis are collection of background data, preliminary visual examination, nondestructive testing, selection and preservation of specimens, mechanical testing, macroexamination, microexamination, metallographic examination, determination of the fracture mechanism, chemical analysis, exemplar testing, and analysis and writing the report. The chapter ends with a discussion on various processes involved in the determination of the fracture mechanism.

This chapter describes the characteristic damage of a mid-air explosion and how it appears in metal debris recovered from crash sites of downed aircraft. It explains that explosive forces produce telltale signs such as petaling, curling, spalling, spikes, reverse slant fractures, and metal deposits. Explosive forces can also cause ductile metals such as aluminum to disintegrate into tiny pieces and are associated with chemicals that leave residues along with numerous craters on metal surfaces. The chapter provides examples of the different types of damage as revealed in the investigation of two in-flight bombings.

This chapter discusses the work of a famous stainless steel pioneer, Edward G. Budd. The discussion covers his early years, his automobile body business, the arrival of novel kind of stainless steel in America, Earl Ragsdale's shot weld patent, the world's first stainless steel airplane, the world's first stainless steel rubber-tired train, the Flying Yankee, the Mark Twain Zephyr, the development of the Budd Company in the war years and postwar years, and a review of the Budd Era.

Parts of machines and equipment that have previously been designed as wrought or fabricated parts, or as cast parts of metals other than steel, are often reconsidered as steel castings. This chapter presents bending test data for several junction designs of L and box sections and discusses redesign from fabrication, forgings, and cast iron. The chapter also includes the benefits of redesign.

This chapter discusses the selection, use, and integration of methods to control process variables in induction heating, including control of workpiece and processing temperature and materials handling systems. The discussion of temperature control includes a review of proportional controllers and heat-regulating devices. Integration of control functions is illustrated with examples related to heating of steel slabs, surface hardening of steel parts, vacuum induction melting for casting operations, and process optimization for electric-demand control. Distributed control within larger manufacturing systems is discussed. The chapter also covers nondestructive techniques for process control and methods for process simulation.

Compared with other deformation processes used to produce semifinished products, the hot-working extrusion process has the advantage of applying pure compressive forces in all three force directions, enhancing workability. The available variations in the extrusion process enable a wide spectrum of materials to be extruded. This chapter focuses on the processes involved in the extrusion of semifinished products in various metals and their alloys, namely tin, lead, lead-base soft solders, tin-base soft solders, zinc, magnesium, aluminum, copper, titanium, zirconium, iron, nickel, and powder metals. It discusses their properties and applications as well as suitable equipment for extrusion. It further discusses the processes involved in the extrusion of semifinished products in exotic alloys and extrusion of semifinished products from metallic composite materials.

Polymer-matrix composites are among the lightest structural materials in use today. They are also highly resistant to corrosion and fatigue and their load-carrying capabilities, such as strength and stiffness, can be tailored for specific applications. This chapter discusses the primary advantages and disadvantages of polymer-matrix composites, how they are produced, and how they perform in different applications. It describes the construction of laminates, the fibers and resins used, and the methods by which they are combined. It explains how strength, modulus, toughness, and high-temperature and corrosion behaviors are determined by the orientation, shape, and spacing of fibers, the number of plies, resin properties, and consolidation and forming methods. The chapter also covers secondary fabrication processes, such as thermoforming, machining, and joining, as well as production equipment and product forms, and include guidelines for optimizing tradeoffs when selecting fibers, resins, and production techniques.

Gears can fail in many different ways, and except for an increase in noise level and vibration, there is often no indication of difficulty until total failure occurs. This chapter begins with the classification of gear failure modes, followed by sections discussing the characteristics of various fatigue failures. Then, it provides information on the modes of impact fractures, wear, scuffing, and stress rupture. Next, the chapter describes the causes of gear failures and discusses the processes involved in conducting the failure analysis. Finally, the chapter presents examples of gear failure analysis.

This chapter examines the static, fatigue, and damage tolerance properties of glass, aramid, and carbon fiber systems. It also explains how delaminations, voids, porosity, fiber distortion, and fastener hole defects affect impact resistance and strength.

Joining comprises a large number of processes used to assemble individual parts into a larger, more complex component or assembly. The selection of an appropriate design to join parts is based on several considerations related to both the product and the joining process. Many product design departments now improve the ease with which products are assembled by using design for assembly (DFA) techniques, which seek to ensure ease of assembly by developing designs that are easy to assemble. This chapter discusses the general guidelines for DFA and concurrent engineering rules before examining the various joining processes, namely fusion welding, solid-state welding, brazing, soldering, mechanical fastening, and adhesive bonding. In addition, it provides information on several design considerations related to the joining process and selection of the appropriate process for joining.