Direct and Back Effects

Abstract

Any practical analysis of the processes of mechanical fatigue, the processes of friction and wear are based on the main idea that the characteristics of the above processes are affected (usually damaging) by numerous factors, all their variety being classified into four groups, viz. factors of design, metallurgy, production process and operation (see Sect. 1.6). The effect of a factor, for example, on changes in the fatigue limit is, as a rule, unidirectional, i.e. it is the same qualitatively irrespective of the variations of the parameter characterizing this factor.