Cutout effects of in-plane loaded lattice-core sandwich panels

To instruct optimal design of sandwich panel with cutout, stress/strain concentration factor (SCF) and failure envelope of composite lattice-core sandwich panel (LSP) with circular cutout under multi-axial in-plane loads were investigated by numerical simulations and verified by digital image correlation (DIC) technique. SCF of the laminated composite skin is much higher than the orthotropic lattice core. Under different loading cases, skin layers with different orientations have different SCFs. SCF is also sensitive to the relation between the cutout diameter and the lattice cell dimension. Intersection of the lattices always produces a local peak value of SCF. Lower SCF can be designed by optimizing the diameter and location of the cutout. Strengthening effects of the strengthening range and strengthening material were discussed to reduce the SCF of the LSP.