This book is intended primarily to be used as a te xtbook, written on the level of senior and graduate students with proficiency in engineering or sciences. It is intended to bring everyone who wants to solve problems in friction and wear to the same understanding of what is (and, more important, what is not) involved. Most engineers and scientists have learned a few simple truths about friction and wear, few of which seem relevant when problems arise. It turns out that the “truths” are often too simple and couched too much in the terms of the academic discipline in...
The phenomenon of friction has been part of daily life since the beginning of human existence. It is no surprise that some of the earliest human activities involved the reduction of friction when it was wasteful, or the use of friction when it could be beneficial. The first category includes the use of vegetable oils and animal fats as lubricants, as well as the use of rolling motion to take advantage of the resulting low resistance to movement.
Since the dawn of history, human activities have always been closely related to friction,
the resistance to sliding. It is thanks to friction that one can stand and walk on
the ground, one can wear clothes, one can make fire by rubbing two sticks together,
or one can even start and stop a car. In these cases friction is very useful for human
beings. In many other cases, however, human activities have been very much hampered
by friction since ancient times. How to diminish friction is one of the most
basic technological problems.
For example, when a heavy...
It is well known that no surface, natural or manufactured, is perfectly
smooth. Nonetheless the idealized case of elastic bodies with smooth surfaces is considered in this chapter as the theoretical reference for the contact
between rough surfaces. The latter will be discussed in Chapter 4 and used as the basis for evaluating the frictional resistance.
This chapter provides classification of metal forming processes based on types of forces applied onto metals. • Mechanics of metal forming will be outlined to understand stress criterion for plastic deformation. • Differences between hot and cold working will be highlighted and advantages-disadvantages of hot and cold working will be given. • Effects of deformation speed and friction on metal working process will be included.
The science of friction, i.e., tribology, is possibly together with astronomy one of the oldest sciences. Human interest in astronomy has many reasons, the awe experienced when observing the dark and endless sky, the fear associated with phenomena such as eclipses, meteorites, or comets, and perhaps also
Tower reported the results of a series of experiments intended to determine the best methods to lubricate a railroad journal bearing. Working with a partial journal bearing in an oil bath, he noticed and later measured the pressure generated in the oil film. Tower pointed out that without sufficient lubrication, the bearing operates in the boundary lubrication regime, whereas with adequate lubrication the two surfaces are completely separated by an oil film. Petrov  also conducted experiments to measure the frictional losses in bearings.
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: The molecular dynamic simulation on impact and friction characters of nanofluids with many nanoparticles system