Crack Growth in Compressive Stress Fields

Abstract

To understand how to analyze Damage Tolerance in an aerospace component loaded in compression one must first obtain correct Fatigue Crack Growth curves. Once the fatigue data curves are correct one could then move forward to understand and develop a method that predicts Fracture Mechanics fatigue lives for designs with high compressive stresses. The investigation yielded ground breaking results that could change the Fatigue Crack Growth data generation standard procedures governed by the ASTM E-647. Also the proposed Design Methodology and Application procedure defined a method to analyze loading conditions with compressive stresses above yield. It is recommended the Compression Pre-Cracking process is standardize and incorporated into the ASTM E-647 procedure by replacing the existing tension pre-cracking process with the proposed Compression Pre-Cracking process. For the Design Methodology and Application it is recommended to validate the hand calculation methodology with experimental results. Key Terms - Compression Pre-cracking, Fatigue Crack Growth, Stress Intensity Factor, Tension Pre-cracking.