ESTIMATION OF THE SIZES OF SECTIONS OF DECELERATION AND ACCELERATION IN CRACK GROWTH INSIDE THE ZONE OF TENSION OVERLOAD INFLUENCE

Abstract

In this work fatigue tests were conducted using eccentrically-stretched compact specimens under
the influence of single tension overload. An increase of the crack growth delay with increasing
of overload level is completely correlated with changes in formation of residual compressive
stresses at the crack tip. Inside the area of overload influence there are different sections of fatigue
crack growth. Expressions to determine the sizes of this sections are proposed. The results of the
comparison of published experimental data with the calculated data obtained using the suggested
expressions are shown. Good agreement of the results clearly confirms the accuracy of the proposed
expressions.
Keywords: life prediction, zone of influence of tension overload, deceleration section, section
of stable crack growth, acceleration section, fatigue tests, residual compressive stresses.