Although the mechanical behavior of carbon nanotubes has been studied extensively in recent years, very few experimental results exist on the shell buckling of nanotubes, despite its fundamental importance in nanotube mechanics and applications. Here we report an experimental technique in which individual multiwalled carbon nanotubes were axially compressed using a nanoindenter and the critical...

In this paper, simulation and analysis of thin steel cylindrical shells with elliptical cutouts under oblique loading were studied using finite element method. First, the numerical results were validated by the results of experimental test performed by an INSTRON 8802 servo hydraulic machine. Also, the effect of cutout angle (θ), cutout size, cutout position (L0/L) and cutout aspect ratios (b/a...

Advanced carbon-fibre composite materials are increasingly used as primary structural components in aviation and aerospace industries due to their high stiffness-to-density ratio. The design of composite aerostructures is required to meet a number of safety criteria, in particular, the damage tolerance. Delaminations, which are caused by the impact of foreign objects (tool drops, runway debris,...

understanding how a cutout influences the load bearing capacity and buckling behavior of cylindrical shells is fundamental in the design of structural components used in automobiles, aircrafts, and marine structures. in this article, simulation and analysis of steel cylindrical shells with various lengths, include quasi elliptical cutout, subjected to axial compression were systematically carri...

Failure in cold-formed steel beams is generally initiated by one of three instabilities: local, distortional, or lateral-torsional buckling. For cold-formed steel joists, purlins, or girts, when the compression flange is not restrained by attachment to sheathing or paneling, distortional buckling may be the predominant failure mode. Experimental results on cold-formed steel beams with unrestrai...

The influences of curvatures and of physical properties on the mechanical stability of the spine were analysed by means of a three-dimensional, geometrical, nonlinear biomechanical model. According to the model, the initial buckling load decreases with increasing lordotic and kyphotic curvatures. When the body weight is taken into account as a load distributed along the whole spine, the calcula...

abstract: the present study deals with the buckling analysis of the laminated composite truncated conical sandwich shells with flexible core subjected to combined axial compressive load and external pressure. higher order governing equations of the motion are presented for conical composite sandwich shells, where they are derived from the hamilton principle. then, by the use of improved higher-...

In the current study the effect of nanoclay content and carbon fiber orientation on the buckling properties of epoxy/nanoclay/ carbon fiber orientation is investigated. Buckling samples were prepared with 1, 3 and 5 wt% of nanoclay and 0, 30 and 45 degrees of fiber orientations based on VARTM technique. The results obtained from the buckling tests showed that adding 1wt% of nanoclay into the pu...

The spline finite strip method (S.F.S.M.) for buckling analysis of plates and plate assemblies subjected to longitudinal compression and bending, transverse compression as well as shear is described. The method allows for the boundary conditions. Local buckling coefficients of plates with different boundary conditions under compression, bending and shear are calculated. Convergence studies with...

Analytical relations between the critical buckling load of a functionally graded material (FGM) Timoshenko beam and that of the corresponding homogeneous Euler–Bernoulli beam subjected to axial compressive load have been derived for clamped–clamped (C–C), simply supported–simply supported (S–S) and clamped–free (C–F) edges. However, no such relation is found for clamped–simply supported (C–S) b...