BACKGROUND Knee osteoarthritis (OA) is one of the most frequent causes of limited mobility and diminished quality of life. Pain is the main symptom that drives individuals with knee OA to seek medical care and a recognized antecedent to disability and eventually joint replacement. Evidence shows that patients with symptomatic OA experience fluctuations in pain severity. Mechanical insults to th...

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 'fishmouth phenomenon' seen in some previously treated retinal detachments is associated with large horeshoe tears and scleral buckling techniques. A method of treating patients with this complication is described in which scleral buckling with implant or explant is not used. The technique utilises intravitreal air tamponade with cryopexy and gives good results. The incidence of patients de...

The work described herein consists of experimental measurement of the post-impact buckling loads of Eglass/epoxy laminates. Composite samples with stacking sequence of [+45/45/90/0]2s were subjected to low-velocity impact loading at energy levels of 36, 56.13, 79.95, 110.31 and 144 J. The impact tests were conducted with a specially developed vertical drop weight testing machine. Impact parame...

This paper investigates the buckling behavior of piezoelectric nanowires under distributed transverse loading, within the framework of the Timoshenko beam theory, and in the presence of surface effects. Analytical relations are given for the critical force of axial buckling of nanowires by accounting for the effects of surface elasticity, residual surface tension, and transverse shear deformati...

Euler was the first who studied for engineering applications important problem of buckling arising in a simple, monolithic beam loaded axially by a concentrated load. As it has been shown from two solutions of the problem due to Timosenko theory, the elastic foundation increases the critical buckling load of the beam. Starting from the previous classical results, a mechanism to enhance the buck...

In this paper, the buckling of carbon nanotubes, modeled as nonlocal one dimensional continua within the framework of Euler–Bernoulli beams, is considered. Both a stress gradient and a strain gradient approach are considered and a variational approach is adopted to obtain the variationally consistent boundary conditions. The dependence of the buckling load on the nonlocal parameter has been det...

We reexamine previous observations of folding kinetics of compressed lipid monolayers in light of the accepted mechanical buckling mechanism recently proposed by L. Pocivavsek et al. [Science 320, 912 (2008)]. Using simple models, we set conservative limits on (a) the energy released in the mechanical buckling process and (b) the kinetic energy entailed by the observed folding motion. These lim...

The cicada uses a rapid sequence of buckling ribs to initiate and sustain vibrations in its tymbal plate (the primary mechanical resonator in the cicada’s sound production system). The tymbalimba, a music controller based on this same mechanism, has a row of 4 convex aluminum ribs (as on the cicada’s tymbal) arranged much like the keys on a calimba. Each rib is spring loaded and capable of snap...

In this paper, the buckling behavior of a composite lattice cylindrical shell is studied and effects of rib defects on the distribution of stress field and buckling response of the shell is investigated. A three dimensional finite element buckling analysis of the lattice shell is carried out using ANSYS suit of program. Geometrical data and material properties of the shell are obtained from the...