Molecules held together by van der Waals forces generally posess bond strengths which are -0 1-1.0% of normal chemical bonds, i.e. 0.1-1.0 Kcal/mole (.35-350 cmi ). Such extremely weak bonds exhi~it vibrational frequencies which lie in the far-infrared, eq. 10-100 cm(1000-100 11m). In order to measure vibration-rotation spectra of van der Waals bonds, one must devise a method which possesses ve...

The effects of amine functionalization of carbon nanotubes (CNTs) and CNTs weight percent (wt. %), on the first bending natural frequencies and damping properties of CNT/epoxy composites are investigated in this paper. CNTs and amine functionalized CNTs (AFCNTs), with two different weight percentages, are used to manufacture the beam shaped specimens. Epoxy, CNT/epoxy (0.25 and 0.5 wt. % of CNT...

in the present study, vibration of cylindrical laminates with different layers and angles were studied. in order to actuate and polarize in radial direction, a piezoelectric layer was located at outer surface of composite shell. laminates were assumed long enough so that plane strain state analysis in 2d can be used properly. in order to satisfy the boundary conditions, variables in terms of fo...

plates and shells are the significant structural components for many engineering and industrial applications. in this study, free vibration analysis of annular plates is investigated. for this, two different numerical methods such as differential quadrature and discrete singular convolution methods have been performed for numerical simulations. frequency values have been obtained via these two ...

The article presents the vibration behavior of bidirectional functionally graded (BDFG) porous plates using new triangular 3-node element (a cubic bubble function for interpolation rotations to enrich bending displacements) which is called MITC3+ element. BDFG have material properties varying in two directions with even and uneven porosity distribution. Based on Hamilton’s principle, motion equ...

The resulting motion in waves can be considered as a superposition of the motion of the body in still water and the forces on the restrained body. In this study the effect of added mass fluctuation on vertical vibration of TLP in the case of vibration in still water for both free and forced vibration subjected to axial load at the top of the leg is presented. This effect is more important when ...

This study presents the effect of vertical and horizontal oriented cracks on free vibration response for circular annular thin plates. To investigate dynamic behavior damaged structures are modeled separately considering horizontal/vertical orientations, ten different locations, four crack sizes. For plates, placed in middle between outer inner edges to directions. The first five resonant frequ...

COMPARISON BETWEEN THREE-POINT AND FOUR-POINT FLEXURAL TESTS 2 TO DETERMINE WOOD STRENGTH OF EUCALYPTUS SPECIMENS 3 Paulo Ricardo Gherardi HEIN*, Loïc BRANCHERIAU 4 *Corresponding author: [email protected] 5 Received: September 21, 2016 6 Accepted: January 24, 2018 7 Posted online: January 25, 2018 8 9 ABSTRACT 10 11 Comparison between flexural wood strength values obtained from three-poin...