Interaction between a notch and cylindrical voids in aluminum single crystals: Experimental observations and numerical simulations

A combined 3D finite element simulation and experimental study of interaction between a notch and cylindrical voids ahead of it in single edge notch (tension) aluminum single crystal specimens is undertaken in this work. Two lattice orientations are considered in which the notch front is parallel to the crystallographic [101¯] direction. The flat surface of the notch coincides with the (010) plane in one orientation and with the (11¯1) plane in the other. Three equally spaced cylindrical voids are placed directly ahead of the notch tip. The predicted load–displacement curves, slip traces, lattice rotation and void growth from the finite element analysis are found to be in good agreement with the experimental observations for both the orientations. Finite element results show considerable through-thickness variation in both hydrostatic stress and equivalent plastic slip which, however, depends additionally on the lattice orientation. The through-thickness variation in the above quantities affects the void growth rate and causes it to differ from the center-plane to the free surface of the specimen.

► In situ observations indicate strong interaction between the notch tip and voids. ► Growth rate of near-tip voids is found to depend strongly on lattice orientation. ► 3D FEA predicts slip traces, lattice rotation and void growth quite well. ► FE results indicate orientation-dependent thickness variation in void growth rate. ► Void growth trends correlate with plastic slip and hydrostatic stress distributions.