No abstract

A theory has been developed for the calculation of relaxation strains when a hole is drilled into a plate with a linearly varying stress f:eld, With this theory a technique was developed for the measurement of residual stresses at the toe of tee fillet welds. The above technique was employed for the measurement of residual stresses at the toe of tee fillets in 1 1/2 in. HY-80 steel with the fillet in the as welded, ground, shot-peened, ground and shot-peened, and mechanically-peened condition. It was found that experimental data conform to the issumed theory, and that residual stresses in as welded tee fillet welds in both the transverse and longitudinal directions appnrach the yield strength of the steel. It was also found that residual stresses are reduced approximately 25 percent by grinding, Z3 percent by shot peening and 50 percent by grinding and shot peening, Medhanical peening drastically affected residual stresses by converting high tension at the toe of the fillet weld to high compression of approximately the same magnitude.

This paper summarizes the findings of an experimental study on the full‐scale stress measurements and fatigue behavior of a full‐size aircraft carrier propeller. Supplementary data on the fatigue characteristics of the manganese bronze propeller material of a patrol craft propeller were included. Fatigue life predictions based on nominal stress and fracture mechanics concepts are analyzed and discussed. There is evidence that with accurate inputs as to stress levels and service loadings, a fracture mechanics approach appears to be a rational method of estimating the fatigue life of large propellers from specimen data.