This chapter discusses the fatigue behavior of bolted, riveted, and welded joints. It describes the relative strength of machined and rolled threads and the effect of thread design, preload, and clamping force on the fatigue strength of bolts made from different steels. It explains where fatigue failures are likely to occur in cold-driven rivet and friction joints, and why the fatigue strength of welded joints can be much lower than that of the parent metal, depending on weld shape, joint geometry, discontinuities, and residual stresses. The chapter also explains how to improve the fatigue life of welded joints and discusses the factors that can reduce the fracture toughness of weld metals.

This chapter discusses the use of mechanical fastening and adhesive bonding, the primary methods for joining polymer matrix composites. It describes and analyzes the basic types of mechanically fastened joints, including single-hole and multirow bolted composite joints. It then reviews the advantages and disadvantages of adhesively bonded joints and compares and contrasts the long-term performance of various joint designs. The chapter also discusses the merits of stepped-lap and bonded-bolted joints.

This chapter presents a comprehensive coverage of mechanical fastening methods. It begins with a discussion on the advantages and disadvantages of mechanical fastening followed by sections providing information on mechanically fastened joints and the selection of the correct fastener system. The chapter then describes important structural fasteners, namely bolts, screws, pins, collar fasteners, rivets, blind fasteners, machine pins, and spring clip fasteners. The following sections describe the process involved in presses, shrink fits, hole generation, and fastener installation. The chapter ends with information on miscellaneous mechanical fastening methods.

Stress severity factors are used in design and analysis to account for stress concentrations, variations in material properties and fabrication quality, and other analytical uncertainties. They indicate the severity of stress in areas that are prone to crack development. This appendix discusses stress severity factors associated with fastener holes in attachment joints.

This chapter reviews materials issues encountered in joining, including challenges involved in welding of dissimilar metal combinations; joining of plastics by mechanical fastening, solvent and adhesive bonding, and welding; joining of thermoset and thermoplastic composite materials by mechanical fastening, adhesive bonding, and, for thermoplastic composites, welding; the making of glass-to-metal seals; and joining of oxide and nonoxide ceramics to themselves and to metals by solid-state processes and by brazing. The classification, types, applications, and the mechanism of each of these methods are covered. The factors influencing joint integrity and the main considerations in welding dissimilar metal combinations are also discussed.

This chapter covers basic machining and assembly operations, with an emphasis on hole preparation for mechanical fasteners. It describes manual, power feed, and automated drilling techniques as well as reaming and countersinking. It discusses various types of fasteners, including rivets, pins, and bolts, along with selection factors and special considerations for composite joints. It also includes information on interference-fit and blind fasteners as well as trimming operations, general assembly considerations, and sealing and painting procedures.

This chapter focuses on tensile testing of three types of engineering components that undergo significant loading in tension, namely, threaded fasteners and bolted joints; adhesive joints; and welded joints. It describes the standardized tensile test for externally threaded fasteners and provides a brief background on relationships among torque, angle-of-turn, tension, and friction. The chapter also describes the test methods covered in the ASTM F 606M standard, namely, product hardness; proof load by length measurement, yield strength, or uniform hardness; axial tension testing of full-sized products; wedge tension testing of full-sized products; tension testing of machined test specimens; and total extension at fracture testing. Finally, the chapter covers tensile testing of adhesive and welded joints.

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.

This chapter discusses the various methods used to join titanium alloy assemblies, focusing on welding processes and procedures. It explains how welding alters the structure and properties of titanium and how it is influenced by composition, surface qualities, and other factors. It describes several welding processes, including arc welding, resistance welding, and friction stir welding, and addresses related issues such as welding defects, quality control, and stress relieving. The chapter also covers mechanical fastening techniques along with adhesive bonding and brazing.

This chapter explains how to join beryllium parts using adhesive bonding and mechanical fastening techniques and discusses the advantages and disadvantages of each method. It describes the stresses that need to be considered when designing adhesive bonds, the benefits and limitations of different adhesives, and surface preparation requirements. It explains how adhesives are applied and cured and how curing times and temperatures affect bonding strength. It also discusses the use of bolts and rivets and the different types of joints that can be made with them.

Soldering and brazing represent one of several types of methods for joining solid materials. These methods may be classified as mechanical fastening, adhesive bonding, soldering and brazing, welding, and solid-state joining. This chapter summarizes the principal characteristics of these joining methods. It presents a comparison between solders and brazes. Further details on pressure welding and diffusion bonding are also provided. Key parameters of soldering are discussed, including surface energy and surface tension, wetting and contact angle, fluid flow, filler spreading characteristics, surface roughness of components, dissolution of parent materials and intermetallic growth, significance of the joint gap, and the strength of metals. The chapter also examines the principal aspects related to the design and application of soldering processes.