Intégration et optimisation de l'assistance a la mise en forme par vibrations

Abstract : This work is focused on the application of mechanical vibrations in cold metal forming process for visco-plastic domain to improve it by obtaining mean forming load reduction, low stresses, less friction, uniform distribution of strains and good surface qualities. For this purpose, analytical model has been developed for vibration assisted forming process with single vibration source. Sinusoidal and triangular vibration waveforms have been integrated in these models and it is found that triangular vibration is more advantageous as compare to traditional sinusoidal due to the control on cycle duty time. It is also observed that the main parameters that control the amount of forging force reduction are: the speed ratio defined by the amplitude of the vibration speed over the mean speed of the die and the sensitivity to strain rate. Analytical model is verified with the help of Finite element simulations performed in FORGE2011 ® and experiments performed with the help of specifically design vibration pot and Lloyd LR30K Universal testing machine or ZWICK/Roell 1200. The scope of this work is further extended by the use multiple vibration sources in the metal forming process. Kinematic study is carried out and it is found that application of multiple vibrations generates progress wave. This kinematic is applied in FORGE2011 ® during the metal forging process with the help of generic press and the reduction in forging load has been observed along with reduction in stress in the material and the modification of the friction on the lower die due to the change in velocity vector direction.
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Submitted on : Wednesday, November 27, 2013 - 4:34:55 PM
Last modification on : Tuesday, May 28, 2019 - 3:40:08 PM
Long-term archiving on : Friday, February 28, 2014 - 9:05:24 AM

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  • HAL Id : pastel-00910246, version 1

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Armaghan Khan. Intégration et optimisation de l'assistance a la mise en forme par vibrations. Autre. Ecole nationale supérieure d'arts et métiers - ENSAM, 2013. Français. ⟨NNT : 2012ENAM0029⟩. ⟨pastel-00910246⟩

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