Browsing by Author "Fuentes, Arturo Alejandro"

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    Dynamic plastic deformation of a free ring subjected to a point load
    (1997) Fuentes, Arturo Alejandro; Angel, Y. C.
    The permanent deformation of a rigid perfectly-plastic unsupported thin ring subjected to a concentrated time-dependent force acting along a diameter is calculated. The analysis is developed for a force pulse of arbitrary shape, and numerical results are obtained for the special case of a triangular force pulse. It is shown that, for sufficiently large values of the applied force, four plastic hinges develop along the ring. Two of the hinges are fixed, and the other two move along the ring as the force varies with time. The motion of the hinges is governed by a system of coupled nonlinear ordinary differential equations that are solved numerically. The parameters that describe the final plastic deformation of the ring are evaluated and shown graphically. Previous studies of this problem provided a numerical solution for the case of a rectangular pulse only.
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    Dynamics of deformed droplets: Thermophysical property measurement using acoustic levitation
    (2000) Fuentes, Arturo Alejandro; Bayazitoglu, Yildiz
    A general theory for the dynamics of aspherical droplets useful to interpret frequency spectra more accurately for thermophysical property measurements was developed. The oscillations of a non-spherical droplet oscillating about an oblate spheroid subjected to external forces are considered. The effect of the static deformation and the interaction between the drop oscillation and the external field on the resonance are investigated. The analysis developed can be extended to consider different static shape deformation shapes. In order to validate the analytical predictions and to conduct further investigations, an experimental apparatus and a novel experimental procedure were developed. Experimental data and observations on the frequency splitting and surface tension, and the dynamics of the droplet in the experimental apparatus are presented. Finally, the effect of fullerenes on some dynamic features of levitated droplets is investigated.