Plastic-Elastic Strains Observed near Loaded Fillets in Stepped Bars

Abstract

The photoelastic reflection technique has been used to study the strains in 10 different models, made of nickel-chromium-molybdenum steel. The shapes of the models were like very thick channel sections. Equal and opposite thrusts were applied to the inner edges of the (constant thickness) ‘flanges’. Calculated peak stress-measured peak strain curves were very similar for all models, although the elastic stress concentration factors varied from 2·2 to 6·2. The ratio (measured peak strain)/(strain if material were elastic) was approximately 1 at twice yield stress, 1 1/2 at three times yield stress and 2 1/4 at four times yield stress. The strain distribution across a section of the ‘web’ of the channel section is also presented for various loads.