This paper is concerned with the buckling of double-walled carbon nanotubes (DWCNTs) under axial load. The DWCNTs are modelled as two cylindrical shells, one shell nested in the other and Winkler springs are introduced to connect them in order to simulate the van der Waals forces between the two nanotubes. By using the Donnell thin shell theory, we derive the governing equations for the bucklin...

The purpose of this paper is to study the effect of presence of fluid within and around a poroelastic circular cylindrical shell of infinite extent on axially symmetric vibrations. The frequency equation each for a pervious and an impervious surface is obtained employing Biot’s theory. Radial vibrations and axially symmetric shear vibrations are uncoupled when the wavenumber is vanished. The pr...

This paper investigates the transverse and torsional wave in singleand double-walled carbon nanotubes (SWCNTs and DWCNTs), focusing on the effect of carbon nanotube microstructure on wave dispersion. The SWCNTs and DWCNTs are modeled as nonlocal single and double elastic cylindrical shells. Molecular dynamics (MD) simulations indicate that the wave dispersion predicted by the nonlocal elastic c...

In this paper, buckling of cylindrical grooved shells under axial load has been examined by theoretical and experimental methods. The shell is made of USA/API – X42 5L steel standards. This material is one of the most common materials used in gas, oil and petrochemical industries. The effect of spiral grooves on cylindrical shell was analyzed, and the results obtained from the Abaqus software w...

The ductile fracture of thin-shell structures was studied here using a localized necking model. punching experiments for unstiffened and stiffened panels were compared with numerical predictions combined model shell elements. plasticity parameters JIS G3131 SPHC steel identified by performing calibration on standard flat bars, notched tension, central hole plane strain shear specimens. beyond t...

In this paper, the plastic limit load of cylindrical shells with opening subject to combined bending moment and axial force are found by finite element method using ANSYS suite of program. The effect of various parameters such as the geometrical ratios of shell and the shape, size, axial and angular position of the opening on the limit load of cylindrical shells under various loading conditions...

The damage tolerance behavior of integrally and conventional stiffened panel is investigated based on the fracture mechanics and finite element analysis. The load bearing capability and crack growth characteristic of both types of the stiffened panels having same configuration subjected to distributed tensile load is examined in this paper. A fourteen-stringer stiffened panel is analyzed for a ...

In this paper, the influence of the constituent volume fractions by changing the values of the power-law exponent with uniform pressure on the vibration frequencies of reinforced functionally graded cylindrical shells is studied. The FGM shell with ring is developed in accordance to the volume fraction law from two constituents namely stainless steel and nickel. These constituents are graded th...

We describe calculations of the properties of quantum fluids inside nanotubes of various sizes. Very small radius (R) pores confine the gases to a line, so that a one-dimensional (1D) approximation is applicable; the low temperature behavior of 1D He is discussed. Somewhat larger pores permit the particles to move off axis, resulting eventually in a transition to a cylindrical shell phase—a thi...