This article reviews the impact response of plastic components and the various methods used to evaluate it.. It describes the effects of loading rate on polymer deformation and the influence of temperature and strain rate on failure mode. It discusses the advantages and limitations of standard impact tests, the use of puncture tests for assessing material behavior under extreme strain, and the application of fracture mechanics for analyzing impact failures. It also develops and demonstrates the theory involved in the design and analysis of thin-walled, injection-molded plastic components.

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 article reviews the major types of gears and the basic principles of gear-tooth contact. It discusses the loading conditions and stresses that effect gear strength and durability. The article provides information on different gear materials, the common types and causes of gear failures, and the procedures employed to analyze them. Finally, it presents a chosen few examples to illustrate a systematic approach to the failure examination.

This article summarizes the various kinds of gear wear, including fatigue, impact fracture, wear, and stress rupture, describes how gear life in service is estimated. It presents the rules concerning lubricants in designing gearing and analyzing failures of gears. The article presents the equations for determining surface durability and life of gears. It tabulates the situations and concepts of pitting failures in gears. The article analyzes some of the more common flaws that affect the life of gear teeth. It reviews the components in the design and structure of each gear and/or gear train that must be considered in conjunction with the teeth.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of pure irons and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the grain-boundary cavitation; slip lines; intergranular fracture; cleavage fracture; notch-impact fracture; oxide inclusions and blowholes; ductile rupture; impact fracture and tensile-test fracture surfaces; fatigue striations; and crack initiation and propagation of pure irons.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of miscellaneous metals and alloys and in identifying and interpreting the morphology of fracture surfaces. The metals and alloys covered include tungsten, iridium, magnesium-base, iron-base, molybdenum-base, and tantalum-base materials. The fractographs illustrate fatigue striations, slow-bending fracture, quasi-cleavage fracture, corrosion-fatigue fracture, fatigue crack, intergranular cleavage, microvoid coalescence, tension-overload fracture, crack propagation, impact fracture, and high-cycle fatigue failure.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of low-carbon steels and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the following: the intergranular fracture, bending impact fracture, brittle fracture, tensile-test fracture, transgranular fracture, cleavage fracture, delayed fracture, corrosion fatigue, inclusion morphology, fatigue crack propagation, and in-service fatigue fracture of various automotive components. These components include tie rod adjusting sleeves, automotive bolts, hydraulic jack shafts, crank handle collars, boiler tubes, drive shafts, bicycle pedal axles, lift-truck hydraulic-piston rods, and steel springs.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of tool steels and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the low-cycle and high-cycle fatigue fractures, tension-overload fractures, impact fractures, microstructure, quench cracking, brittle-in-service failure, hydrogen embrittlement, stress-corrosion cracking, and grain-boundary cracking of tool steel components. These components include diesel engine injector plungers, rivet-heading tools, circular saw blades, and open-header dies.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of AISI/SAE alloy steels (4xxx steels) and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the brittle fracture, ductile fracture, impact fracture, fatigue fracture surface, reversed torsional fatigue fracture, transgranular cleavage fracture, rotating bending fatigue, tension-overload fracture, torsion-overload fracture, slip band crack, crack growth and crack initiation, crack nucleation, microstructure, hydrogen embrittlement, sulfide stress-corrosion failure, stress-corrosion cracking, and hitch post shaft failure of these steels. The components considered in the article include tail-rotor drive-pinion shafts, pinion gears, outboard-motor crankshafts, bull gears, diesel engine bearing cap bolts, splined shafts, aircraft horizontal tail-actuator shafts, bucket elevators, aircraft propellers, helicopter bolts, air flasks, tie rod ball studs, and spiral gears.