Buckling of tube-like shells filled with other material under uniform axial compression

Symmetrical buckling of steel tube-like shell structures fully filled with a softer material is considered. Such a compound cross-section, after assuming complete condensation of the contained material, is subjected to uniform axial compression by means of two rigid end plates. We further assume simple boundary conditions on both ends with zero radial displacements. The proposed solution allows establishment of the effect of hoop stresses on the load-carrying capacity of the filled tube.