We present a numerical study of the shape taken by a spherical elastic surface when the volume it encloses is decreased. For the range of 2D parameters where such a surface may model a thin shell of an isotropic elastic material, the mode of deformation that develops a single depression is investigated in detail. It occurs via buckling from sphere toward an axisymmetric dimple, followed by a se...

Abstract This paper uncovers new manifestations of the homoclinic snaking mechanism in post-buckling regime a pressurized thin cylindrical shell under axial load. These forms tend to propagate either wholly or partially direction that is orthogonal applied load and so, unlike earlier Woods & Champneys (1999, Heteroclinic tangles unfolding degenerate Hamiltonian Hopf bifurcation. Phys. D, 12...

The aim of this paper is to determine the critical buckling load for simply supported thin shallow spherical shells made of functionally graded material (FGM) subjected to uniform external pressure. A metal-ceramic functionally graded (FG) shell with a power law distribution for volume fraction is considered, where its properties vary gradually through the shell thickness direction from pure me...

Collapse by buckling a quite common phenomenon in sheets under pressure. When these structures caused by defects such as corrosion and cracks the time of the occurrence of this phenomenon is sensitive and critical load to be significantly reduced. Therefore, in this article sheet of aluminum Al 1200 by cracks in a part of the sheet will be considered. Left angle on the critical buckling load ef...

We explore the effect of precisely defined geometric imperfections on the buckling load of spherical shells under external pressure loading, using finite element analysis that was previously validated through precision experiments. Our numerical simulations focus on the limit of large amplitude defects and reveal a lower bound that depends solely on the shell radius to thickness ratio and the a...

This study presents a new end-closure design, using a numerical approach, to eliminate the buckling that occurs at the bottom end of DOT-4BA propane cylinders. When the bottom heads are subjected to test pressure they often buckle, which causes instability of the propane cylinders. That instability is the cylinder’s loss of upright standing. The buckling was predicted using both experimental an...

Aims—To study the eVects of segmental scleral buckling and encircling procedures on tissue circulation in the human optic nerve head (ONH) and choroid and retina. Methods—Using the laser speckle method, the normalised blur (NB) value, a quantitative index of tissue blood velocity, was measured every 0.125 seconds and averaged over three pulses in the optic nerve head (NBONH) and choroid and ret...