Cross-grain specimens made of 7075-T6 aluminum-alloy extrusion were subjected to repeated axial loads until fatigue cracks of various lengths were formed. The specimens were then subjected to static tests to deter?mine the residual static strength. Small cracks resulted in dispropor?tionately large reductions of static strength. Comparison of these results with results previously obtained for loading in the with-grain direction revealed no significant difference. However, it is cautioned that cases may arise in which the cross-grain residual static strength of 7075-T6 or other materials is considerably inferior to the with-grain residual static strength, depending upon the relative shapes of the stress-strain curves. The effects of biaxiality and ductility on the notch sensitivity under static loading of sharply notched specimens are discussed in appendixes.
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