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This book is mostly intended for beginners in mechanical engineering. Undoubtedly, experienced engineers may find a plentiful supply of useful material as well. However, we conceived of this work primarily with novices in mind. We remember all too well how we joined the engineering workforce upon graduating from college, not knowing where to begin. Admittedly, there is still much we don’t know, as the processes in working machines are numerous and complex in nature.
Nevertheless, we hope that thoughtful engineers will profit from our experience. As one doctor singularly expressed, “What we know is an enormous mass of information, and what we don’t know is ten times greater.” We are skeptical about the tenfold estimate; presumably, it is much more. The problem, however, lies not only in the volume of knowledge but also in the fact that most of our knowledge is based on experience in the manipulation of experimental data, whereas many of the laws that govern physical processes are known only partly or not at all. Furthermore, natural, physical processes are statistical in nature, so that as a rule we can’t be completely confident that our actions will bring the desired result.
Despite this, what we do know allows us in most cases to solve fairly difficult technical problems. If it is agreed upon that life is movement, then the being of machines can also be called life. To concentrate on the “physiology” of machines, we generally will not refer very much to the change in location of a mechanism’s parts in relation to each other. Instead, we will mainly consider elastic and plastic deformations of parts under applied forces, changes in the structure of metals under the influence of stress (in the crystals and on their borders), temperature fluctuations, aggressive environments, and the effects of friction combined with aggressive surroundings, and so on.
In all, the life of the machines proves to be very diverse and deserves attentive study. Anyway, machines are in many respects similar to living creatures. Their birth is laborious. They get afflicted with childhood illnesses (the period of initial trials) and undergo a sort of adolescence (the break-in period); then they work for a long time, get old, and eventually pass away. Machines ache from rough handling; their bodies collect scratches and dents which deteriorate their health and weaken their capacity for work.
They suffer from dirt, overheating, and thirst from a lack of lubrication. They also overexert themselves when given loads that are beyond their strength and will perish if nobody looks after their well being. They get tired in the same way from hard work and require check ups, preventative maintenance, and treatment just as people do. They also suffer and become unwell if they are not protected against moisture, heat or cold, soiling, and corrosion. It is no wonder that such terms from the world of the living as “aging,” “fatigue,” “inheritance,” “survivability,” and others have entered the technical lexicon. Just as some books focus on the physiology of animals’ bodies and habits, this book is concerned with the life phenomena of machines and their parts.
We tried to avoid recommendations as “Do this, it’s good” or “Don’t do this, it’s bad.” As with biological life, it is not always possible to say definitely what is good and bad irrespectively of the machine. “Ages ago,” in 1948, a group of teenagers visited a small electric power station in a small town. This town, just as thousands of other towns and cities in Russia at that time, had been virtually destroyed during the war, leaving many families living in makeshift shelters.
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