Klesnil and Lucas have been actively involved in research on the basic aspects of fatigue for a score of years and are deservedly well recognized for their many contributions to our knowledge of the topic, particularly in areas of dislocation structures, cyclic stress-strain behavior and crack growth analysis, for example. The present book is organized about these areas of fatigue with which they have dealt and the treatments reflect their perspective. Their views have also been influenced by the works of many other researchers as indicated by the 410 references cited from countries in the east as well as the west. The seven chapters cover: cyclic stressstrain response; fatigue crack nucleation; fatigue-crack propagation; fatigue-life curves; notched behavior; and fatigue life under random loading. Topics such as elevated temperature fatigue, corrosion fatigue, and the influence of metallurgical structure on fatigue are not treated to any extent. The text, which has been translated from Czechosloviakian to English by Lucas, is clearly written. The treatment is based on current knowledge of the underlying mechanisms of fatigue crack initiation and growth, and since this knowledge is far from complete, it is not surprising that the authors must resort to semi-empirical approaches to provide quantitative treatment of the subject. The book should be of value to researchers and graduate students concerned with the subject of fatigue.

Abstract-Low cycle plastic stress-strain response and fatigue life of low carbon steel in variable amplitude loading is investigated. Repeated block straining with defined probability distribution of strain peaks within a block was chosen. With the help of rain-flow analysis of a strain block the cyclic hardening/softening curves as well as the service cyclic stress-strain curves during random amplitude block loading were obtained. The relation between service stress-strain curves and the basic stress-strain curve was established. The fatigue life prediction based on the actual cyclic stress-strain response and rain-flow analysis was found to be in agreement with experimental results.

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Starting from a knowledge of inhomogeneous dislocation structures observed in cyclically strained metals, a model for cyclic straining is developed. A distribution of volumes with different internal critical flow stresses is assumed characterized by a probability density function. A generalization which includes a thermally activated component of the flow stress is derived assuming that the saturated microscopic effective stress, uNes, is equal in all volumes. The relations to obtain the probability density function from experimental data are derived. The theory yields the macroscopic internal stress, o,, and the macroscopic effective stress, o,, along the hysteresis loop. Experimental observations on cyclically strained metals can be explained using this statistical theory.