The Effect of External Skin on Buckling Strength of Composite Lattice Cylinders Based on Numerical and Experimental Analysis

Currently, lattice composite structures have many applications in aerospace industries. The present research analyzed the effect of an external skin consisting of a lattice’s cylindrical shell on the buckling strength of composite materials, both numerically and experimentally. Two classes of specimens, with and without external skins, were fabricated using the filament winding process. To find the buckling strength of the fabricated samples, tests were carried out. For validation of the experimental results, the finite element method was used to test the shells under the same testing conditions. The results of the experimental and numerical tests showed good agreement with one another, revealing that the lattice cylindrical shell specimen with the outer skin had a much higher buckling strength than the one without the outer skin (≈50%). The added weight of the outer skin was negligible compared to the overall weight of the lattice cylindrical shell, and the external skin had a tremendous positive effect on the buckling strength to weight ratio of the lattice composite structures.

Keywords:

Lattice structures , Buckling , FEM , Stiffened composite cylindrically shell