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 ...

Abstract Dielectric elastomer (DE) actuators are deformable capacitors capable of a muscle-like actuation when charged. When subjected to voltage, DE membranes coated with compliant electrodes may form wrinkles due the Maxwell stress. Here, we develop numerical approach based on finite element method (FEM) predict morphology wrinkled mounted rigid frame. The includes two steps: (I) pre-buckling...

Nonlinear ultrasonic waves in solids have shown good sensitivity to quasi-static stresses. The stress sensitivity of elastic waves is typically associated to finite strains (e.g. theory of acoustoelasticity). In the case of waveguides, classical nonlinear theories for guided waves are still based on the assumption of finite strains. In the case of constrained solids subjected to thermal excursi...

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...

PANDA2, a computer program for the minimum-weight design of elastic perfect and imperfect stiffened cylindrical panels and shells under multiple sets of combined loads, is used to obtain optimum designs of uniformly axially compressed elastic internal T-ring and external T-stringer stiffened cylindrical shells with initial imperfections in the form of the general buckling mode. The optimum desi...

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...

This paper was to verify the STAGS (general shell, geometric and material nonlinear) code and the critical crack-tip-opening angle (CTOA) fracture criterion for predicting stable tearing in cracked panels that fail with severe out-of-plane buckling. Materials considered ranged from brittle to ductile behavior. Test data used in this study are reported elsewhere. The STAGS code was used to model...