Numerical–Experimental Study of the Combined Influence of Hole- and Dent-Type Stress Concentrators on the Mechanical Properties of Structurally Similar Samples

The mutual influence of stress concentrators in the form of a dent (made by a hemispherical indenter 25 mm in diameter to a depth of the sheet thickness) and a hole 4 mm in diameter in a thin 1.5- or 3.0-mm-thick skin on the static strength and fatigue life of structurally similar samples made of a 1163AT aluminum alloy is studied. The presence of a dent does not decrease the static strength, while the strength decreases by ~8% regardless of the location of a hole with respect to a dent for combined dent + hole stress concentrators. The position of a hole relative to the center of a dent weakly affects the slope of a fatigue curve, whereas the displacement of a hole from the center to the edge of the dent leads to a decrease in the fatigue life.