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...

We investigate buckling of soft elastic capsules under negative pressure or for reduced capsule volume. Based on nonlinear shell theory and the assumption of a hyperelastic capsule membrane, shape equations for axisymmetric and initially spherical capsules are derived and solved numerically. A rich bifurcation behavior is found, which is presented in terms of bifurcation diagrams. The energetic...

Unsymmetrical buckling of nonuniform circular plates with elastically restrained edge and subjected to normal pressure is studied in this paper. The asymmetric part the solution sought terms multiples harmonics angular coordinate. A numerical method employed obtain lowest load value at which waves circumferential direction can appear. effect material heterogeneity boundary on examined. For a pl...

The paper presents the results of a study bifurcation axisymmetric equilibrium forms round plates under various conditions for fixing outer edge. It is shown that case sliding edge, analytical, asymptotic and finite element approaches give close results. When edge plate hinged, buckling to non-axisymmetric state occurs at much higher load with formation smaller number waves than boundary condit...

In this article, the axisymmetric mechanical buckling of thin cylindrical shell made of functionally graded material (FGM) is considered. The governing equations for a thin cylinder based on the first-order shell theory and Timoshenko's assumptions are obtained. The equations are derived using the Sanders simplified kinematic relations and the principle of work and energy. The constituent mater...

We study transverse impacts of rigid objects on a free elastic membrane, using thin circular sheets of natural rubber as experimental models. After impact, two distinct axisymmetric waves propagate in and on the sheet. First a tensile wave travels at sound speed leaving behind the wave front a stretched domain. Then, a transverse wave propagates on the stretched area at a lower speed. In the st...