No abstract

The integrated electrochemical grinding machining has received wide acceptance in the aircraft turbine industry for the machining of blades, vanes, and honeycomb seal rings. Also, medical devices, instruments and forceps, shells, precision nozzles, instrument coupling, and air rotor motors that produced from stainless steel and new materials have all successfully been accomplished with electrochemical grinding. To improve the metal removal rate and to reduce the surface roughness ( Ra) of the electrochemical grinding at high voltages, an integration between the alumina abrasive jet and the electrochemical grinding machining has been performed. The effect of the Al2O3 abrasive content on the metal removal rate and the Ra of the K110 alloy steel using Everite electrochemical grinding 618 at different voltages, different feed rates, different electrolyte NaCl concentrations, and different depths of the cut were successfully investigated. The results revealed that the abrasive electrochemical grinding was better than the electrochemical grinding results. The maximum effect of the Al2O3 on the metal removal rate was achieved at 5 wt.%. The current density in the machining gap was affected by the addition of the Al2O3, where it was decreased at percentages over 5-wt.% Al2O3. The abrasive electrochemical grinding resulted in lower surface roughness than the electrochemical grinding process.

No abstract

The location selection of facilities became a major interest for the organizations to establish their planned business for a long period of time. The choice of the best location among a set of candidate locations is a complex process. Although the multiple criteria decision making (MCDM) methods are applicable for location selection problems, different solutions can be obtained using different MCDM methods. Thus, a comparative study between four different MCDM methods was applied within numerical example to show the deviations in ranking of the alternatives that occurs when different methods are used. The weights of attributes are assigned using objective method namely Entropy weight method. The rank disagreements are expressed using spearman`s correlation coefficients.

The Absolute Nodal Coordinate Formulation (ANCF) has been initiated in 1996 by Shabana (Computational Continuum Mechanics, 3rd edn., Cambridge: Cambridge University Press, 2008). It introduces large displacements of planar and spatial finite elements relative to the global reference frame without using any local frame. A sub-family of beam, plate and cable finite elements with large deformations are proposed and employed the 3D theory of continuum mechanics. In the ANCF, the nodal coordinates consist of absolute position coordinates and gradients that can be used to define a unique rotation and deformation fields within the element. In contrast to other large deformation formulations, the equations of motion contain constant mass matrices as well as zero centrifugal and Coriolis inertia forces. The only nonlinear term is a vector of elastic forces. This investigation concerns a way to generate new finite element in the ANCF for laminated composite plates. This formulation utilizes the assumption that the bonds between the laminae are thin and shear is non-deformable. Consequently, the Equivalent Single Layer, ESL model, is implemented. In the ESL models, the laminate is assumed to deform as a single layer, assuming a smooth variation of the displacement field across the thickness. In this paper, the coupled electromechanical effect of Piezoelectric Laminated Plate is imposed within the ANCF thin plate element, in such a way as to achieve the continuity of the gradients at the nodal points, and obtain a formulation that automatically satisfies the principle of work and energy. Convergence and accuracy of the finite-element ANCF Piezoelectric Laminated Plate is demonstrated in geometrically nonlinear static and dynamic test problems, as well as in linear analysis of natural frequencies. The computer implementation and several numerical examples are presented in order to demonstrate the use of the formulation developed in this paper. A comparison with the commercial finite element package COMSOL MUL-TIPHYSICS (http://www.comsol.com/) is carried out with an excellent agreement.