We show that the number of concentric graphene cylinders forming a carbon nanotube can be found by squeezing the tube between an atomic force microscope tip and a silicon substrate. The compressed height of a single-walled nanotube (double-walled nanotube) is approximately two (four) times the interlayer spacing of graphite. Measured compression forces are consistent with the predicted bending ...

U-shaped thin-walled concrete bridge beams usually suffer the combined actions of flexure, shear and torsion, but no research about the behavior of U-shaped thin-walled RC beams under combined actions has been reported in literature. Three large specimens of U-shaped thin-walled RC beams were tested under different torque–bending moment ratios (T–M ratios) of 1:5, 1:1 and 1:0 to investigate the...

A fully-coupled, finite-element method is used to investigate the steady flow of a viscous fluid through a thin-walled, elastic tube mounted between two rigid tubes. The steady, three-dimensional, Navier–Stokes equations are solved simultaneously with the equations of geometrically-non-linear, Kirchhoff–Love shell theory. If the transmural (internal minus external) pressure acting on the tube i...

in this paper, the radial breathing mode (rbm) frequencies of multi-walled carbon nanotubes (mwcnts) are  obtained based on the multiple-elastic thin shell model. for this purpose, mwcnt is considered as a multiple concentric elastic thin cylindrical shells, which are coupled through van der waals (vdw) forces between two adjacent tubes. lennard-jones potential is used to calculate the vdw forc...

Bovine sarcocystosis is an economically important disease worldwide caused by the apicomplexan protozoan, Sarcocystis species. There are three main species of cattle Sarcocystis; S. cruzi (S. bovicanis), S. hirsuta (S. bovifelis) and S. hominis (S. bovihominis). The current study was conducted to identify Sarcocystis species infecting slaughtered cattle at Sharkia province, Egypt using light an...

As a typical buffer energy absorbing structure, thin-walled tube filled with foam aluminum has good mechanical properties and absorption characteristics. Therefore, the axial compression performance of square was experimentally studied by quasi-static loading method. On basis existing experimental research theoretical analysis, strain rate is introduced into dynamic theory, mathematical model a...

In this paper a new element for analysis of thin-walled structures is presented, and the effects of secondary shear stresses on longitudinal displacements are examined. Since the Interpolation Functions are based on non-uniform torsional differential equations, the analysis of stiffness matrix is facilitated. Therefore, its ability to produce accurate results with the least number of elements i...

EDF Energy has the requirement to detect and size lack of penetration type defects in thin-walled stainless steel components. A high frequency ultrasonic phased array inspection technique has been successfully developed and applied to thin walled pipes and is currently used as an ENIQ qualified inspection on nuclear plant. The welds are manufactured with an autogenous Tungsten Inert Gas (TIG) w...

The axial crushing of thin-walled tubes has been the subject of extensive research in the past. The existing kinematic models for predicting crushing behavior of axially loaded thin-walled tubes are systematically reviewed and analyzed. The advantages and limitations of each model are discussed. A new chain link model for circular tubes and square tubes is presented and studied in detail. Unlik...

Aiming at the problems of complex processing technology, uneven deformation, and poor forming accuracy multi-curvature positive Gaussian slewing egg-shaped shells, it is proposed to use unidirectional loading rubber flexible medium bulging technology improve tube deformation distribution enhance plastic bionic shells. By analyzing structure manufacturing method this paper explores optimization ...