The femoral head deteriorates in osteonecrosis. As a consequence of that, the cortical shell of the femoral head can buckle into the cancellous bone supporting it. In order to examine the buckling scenario we performed numerical analysis of a realistic femoral head model. The analysis included a solution of the hip contact problem, which provided the contact pressure distribution, and subsequen...

Thin solid shell contrast agents bubbles are expected to undergo different volume oscillating behaviors when the acoustic power is increased: small oscillations when the shell remains spherical, and large oscillations when the shell buckles. Contrary to bubbles covered with thin lipidic monolayers that buckle as soon as compressed: the solid shell bubbles resist compression, making the buckling...

This paper employs the atomic-scale finite element method (AFEM) to study critical strain of axial buckling for carbon nanotubes (CNTs). Brenner et al. “secondgeneration” empirical potential is used to model covalent bonds among atoms. The computed energy curve and critical strain for (8, 0) single-walled CNT (SWNT) agree well with molecular dynamics simulations. Both local and global buckling ...

One of the important issues in the study of steel frames is to find a suitable formulation for semi-rigid connections. In this paper, the explicit stiffness matrix for a two-dimensional beam-column element having end-flexibilities is derived. The effects of the lateral uniformly distributed load on the deflection are considered. Both tensile and compressive axial loads are also taken into accou...

In this study, the dynamic buckling of the embedded laminated nanocomposite plates is investigated. The plates are reinforced with the single-walled carbon nanotubes (SWCNTs), and the Mori-Tanaka model is applied to obtain the equivalent material properties of them. Based on the sinusoidal shear deformation theory (SSDT), the motion equations are derived using the energy method and Hamilton's p...

This paper presents an analytical method to calculate the buckling stress of a rectangular thin plate under nonuniform applied axial stresses. Two cases are considered, buckling of a plate simply supported on all four sides and buckling of a plate simply supported on three sides with one unloaded edge free and the opposite unloaded edge rotationally restrained. These two cases illustrate the in...

PURPOSE To test the efficacy and safety of a biodegradable collagen-glycosaminoglycan (CG) polymer as the material for scleral buckling in rabbit eyes. METHODS Segmental scleral buckling was performed by using a silicone sponge in one eye and a biodegradable CG polymer in the other eye of 20 rabbits. Wound and conjunctival reactions were evaluated by external photographs 1 day and then every ...

The problem of the out of plane buckling of polar orthotropic armuli under uniform internal or external pressure loading has been investigated with the assumption of axisymmetry by numerous researchers. In this paper, the buckling of polar and rectilinearly orthotropic annuli subjected to internal or external pressure loading is examined without restriction to axisymmetric buckling modes. The b...

PURPOSE To evaluate changes in higher-order aberrations (HOAs) after scleral buckling surgery for the treatment of rhegmatogenous retinal detachment (RD). DESIGN Prospective observational comparative case series. PARTICIPANTS The study included 67 eyes of 67 rhegmatogenous RD patients undergoing scleral buckling surgery, and the fellow normal eyes comprised the control group. Twenty-seven e...

Open cross-section, thin-walled, cold-formed steel columns have at least three competing buckling modes: local, distortional, and Euler ~i.e., flexural or flexural-torsional! buckling. Closed-form prediction of the buckling stress in the local mode, including interaction of the connected elements, and the distortional mode, including consideration of the elastic and geometric stiffness at the w...