2,780 research outputs found
Contact angle of sessile drops in Lennard-Jones systems
Molecular dynamics simulation is used for studying the contact angle of
nanoscale sessile drops on a planar solid wall in a system interacting via the
truncated and shifted Lennard-Jones potential. The entire range between total
wetting and dewetting is investigated by varying the solid--fluid dispersive
interaction energy. The temperature is varied between the triple point and the
critical temperature. A correlation is obtained for the contact angle in
dependence of the temperature and the dispersive interaction energy. Size
effects are studied by varying the number of fluid particles at otherwise
constant conditions, using up to 150 000 particles. For particle numbers below
10 000, a decrease of the contact angle is found. This is attributed to a
dependence of the solid-liquid surface tension on the droplet size. A
convergence to a constant contact angle is observed for larger system sizes.
The influence of the wall model is studied by varying the density of the wall.
The effective solid-fluid dispersive interaction energy at a contact angle of
90 degrees is found to be independent of temperature and to decrease linearly
with the solid density. A correlation is developed which describes the contact
angle as a function of the dispersive interaction, the temperature and the
solid density. The density profile of the sessile drop and the surrounding
vapor phase is described by a correlation combining a sigmoidal function and an
oscillation term
Handbook of structural stability part II : buckling of composite elements
The local buckling of stiffener sections and the buckling of plates with sturdy stiffeners are reviewed, and the results are summarized in charts and tables. Numerical values of buckling coefficients are presented for longitudinally compressed stiffener sections of various shapes, for stiffened plates loaded in longitudinal compression and in shear, and for stiffened cylinders loaded in torsion. Although the data presented consist primarily of elastic-buckling coefficients, the effects of plasticity are discussed for a few special cases. (author
Handbook of structural stability part VI : strength of stiffened curved plates and shells
A comprehensive review of failure of stiffened curved plates and shells is presented. Panel instability in stiffened curved plates and general instability of stiffened cylinders are discussed. The loadings considered for the plates are axial, shear, and the combination of the two. For the cylinders, bending, external pressure, torsion, transverse shear, and combinations of these loads are considered. When possible, test data and theory were correlated. General instability in stiffened cylinders was investigated. For bending and torsion loads, test data and theory were correlated. For external pressure several existing theories were compared. As a result of this investigation a unified theoretical approach to analysis of general instability in stiffened cylinders was developed. (author
Handbook of Structural Stability Part I: Buckling of Flat Plates
The various factors governing buckling of flat plates are critically reviewed and the results are summarized in a comprehensive series of charts and tables. Numerical values are presented for buckling coefficients of flat plates with various boundary conditions and applied loadings. The effects of plasticity are incorporated in non dimensional buckling charts utilizing the three-parameter description of stress-strain curves
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