This paper is concerned with the buckling of double-walled carbon nanotubes (DWCNTs) under axial load. The DWCNTs are modelled as two cylindrical shells, one shell nested in the other and Winkler springs are introduced to connect them in order to simulate the van der Waals forces between the two nanotubes. By using the Donnell thin shell theory, we derive the governing equations for the bucklin...

In this paper, buckling behavior of moderately thick functionally graded rectangular plates resting on elastic foundation subjected to linearly varying in-plane loading is investigated. The neutral surface position for a functionally graded plate which its material properties vary in the thickness direction is determined. Based on the first-order shear deformation plate theory and the neutral s...

We identify a new structure-property connection in the skeletal elements of the marine sponge Tethya aurantia. The skeletal elements, known as spicules, are millimeter-long, axisymmetric, silica rods that are tapered along their lengths. Mechanical designs in other structural biomaterials, such as nacre and bone, have been studied primarily for their benefits to toughness properties. The struct...

An algorithm based on Semi-Definite Programming (SDP) formulation is proposed for optimum design for specified linear buckling load factor. Optimal trusses and frames are computed by using the primal-dual interior-point method for SDP. It is well known that optimizing structures under buckling constraints is difficult because of nondifferentiability of the buckling load factors for the case of ...

Compressing a thin elastic film attached to a thick compliant substrate can lead to buckling instability. Two commonly observed buckling modes, buckle-delamination and wrinkling, have each been analyzed separately in previous studies. Recent experiments have observed that the two modes can co-exist and co-evolve. In this paper, by analytical and finite element methods, we present a study on con...

The initial postbuckling behavior and imperfection sensitivity of truss-type structures in which the joints do not transmit moments is determined by means of the Lyapunov-SchmidtKoiter approach. Such structures possess local buckling modes involving the buckling of individual members, and global modes involving axial deformations of all members but no member buckling. Of particular interest is ...

Buckling analysis of thin cylindrical shells is very important due to their production process.  Usually longitudinal and transversal stiffeners are used to increase the buckling stiffness. In this paper, considering a thin cylindrical shell with longitudinal and transversal ribs subjected to axial force and lateral pressure, the influence of different aspect of axial force to lateral pressure ...

Optimum laminate configuration for minimum weight of filament–wound laminated conical shells subject to buckling load constraint is investigated. In the case of a laminated conical shell the thickness and the ply orientation (the design variables) are functions of the shell coordinates, influencing both the buckling load and its weight. These effects complicate the optimization problem consider...