This study presents optimization of planetary gear train in a specific configuration. General characteristics of planetary gear trains are discussed briefly. A compound configuration for planetary gear train is selected and an optimization study is performed for this configuration. For the given input power, motor speed and overall gear ratio, modules, facewidths, teeth numbers of gears are found, satisfying the condition of minimum kinetic energy of the gear trains. In optimization, the objective is set to minimization of kinetic energy. Allowable bending stress and allowable contact stress are considered as design constraints. Minimum teeth number for a given pressure angle, center distance, recommendation on the facewidth, limitations on teeth ratios are considered as geometrical and kinematical constraints. The Matlab ® Optimtool optimization toolbox is used. Results for certain operating conditions are obtained and tabulated.

A study of the influences of press ram pulsation on deep drawability of dual phase steel sheet is presented. General characteristics of deep drawing process, press ram pulsation technique and dual phase steels are briefly discussed. A finite element model is used to evaluate the influence of pulse motion profile of press ram on the thickness reduction of steel sheet and forming load. Commercial finite element software package DEFORM-3D is used for modelling and simulation of cylindrical cup drawing. The effects of superimposed low frequency vibrations of the press ram are investigated. Pulsation amplitudes of 0.5, 0.25, and 0.125 mm are created on the die with the corresponding pulsation frequencies of 5, 10, and 20 Hz. Finite element simulations are carried out using material model of dual phase (DP600) steel, that is one of the most widely used materials in automobile industry, in order to improve crash safety and fuel economy. Results obtained with press ram pulsation are compared with results for the conventional press ram motion and significant effect of proposed method is demonstrated.

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In this study, Ultrasonically Assisted Deep Drawing Process was developed in order to improve formability of sheet metals in Conventional Deep Drawing Process. Effects of ultrasonic vibrations, applied onto the blank holder in axial direction, on formability of sheet metal were investigated numerically by finite element analyses, and the results of such analyses were verified by deep drawing experiments. In the numerical study, a methodology for two-stage finite element analyses including transient structural and forming analysis was developed. In conventional and ultrasonically assisted deep drawing analyses, limiting drawing ratios and maximum drawable cup depths for DC01 and DC04 materials prone to certain process parameters were compared. With application of ultrasonic vibrations, an increase of up to 9% in limiting drawing ratio and up to 26% in cup depth were achieved. In the analyses performed on circular materials of identical diameters, it was determined that the thinning on sheet metal decreased by up to 43%. As result of the validation experiments, increase in limiting drawing ratio and cup depth was achieved as 11% and 31%, respectively. Numerical results were found to be in good agreement with experimental results since dynamic impact, stress superposition and contact separation effects of ultrasonic vibrations could be effectively modeled in finite element analyses with the proposed method. Small differences in obtained results may be due to the reason that it was not possible to involve the effects of acoustic softening and friction coefficient reduction on the material in numerical analyses.

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