Abstract

ROBLES OCAMPO, José Billerman et al. Caracterización de las No-Linealidades de la fuerza autoexitada en el proceso de rectificado sin centro. Ingenier. mecáni. tecnolog. desarroll [online]. 2010, vol.3, n.5, pp.179-185. ISSN 1665-7381.

The geometric irregularities that the workpiece presents during the centerless grinding process are a source of dynamic instability and self-excited nonlinear phenomena. The cylindrical surface presents deformations under some cutting conditions; this effect produces two phenomena that cause nonlinear behavior: one is the generation of vertical acceleration with jumps such as "Jerk"; and the second is a contact loss between the workpiece and the grinding wheel due to the lack of cylindricity. This second effect modifies the system stiffness generating the nonlinear behavior. In this work, a novel nonlinear model of the self-excited force in the centerless grinding process is developed. This model is a result of the polygonal workpiece profile and the contact loss between the workpiece and the grinding wheel. A centerless grinding machine and a cylindrical workpiece were used for this research. The model obtained in this work is based on the assumption that the workpiece profile is polynomial and the identification of the number of the polygon critic sides that in other works no is developed.

Keywords : Centerless grinding; self-excited forces; polygon profile; instability; nonlinear model.