The influence of the very first compression cycle on subsequent Mode I crack growth in notched plates of ductile solids subject to fully compressive cyclic loads has been examined in this work. Whereas stable crack growth occurs from the root of the notch over hundreds of thousands of compression cycles, the amplitude of the very first compression cycle is found to have a decisive effect on the total distance of crack advance. Specifically, a three-fold increase in the stress amplitude during the first compression cycle alone leads to more than a ten-fold increase in the total distance of crack growth during subsequent cycles. Finite element calculations of the crack closure stress levels during cyclic compression are in concurrence with the experimental results of closure stresses (measured from changes in compliance) for a lower strength steel. A brief discussion is also presented of the effects of periodic compressive overloads on crack growth behavior under far-field cyclic compression.

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