| The amount of energy absorbed at mechanical interfaces is as a subject of great interest, particularly in high-speed machining. An increase in energy absorption at the machine tool spindle to toolholder connection would lead to a system more defiant to self-excited vibration known as chatter phenomenon, enabling thus, among other things, an increase in the maximum allowable depth of cut and, as a consequence, the productivity of the machine tool. Chatter occurs because the energy absorber element (damper) capacity of the machine tool system is not sufficient to absorb the portion of the cutting energy transmitted to the system. Previous work done at UNC Charlotte has shown a non-linear behavior of the machine tool toolholder system. The non-linearity was found to be more pronounced for structured surface toolholders. It is therefore the primary purpose of this dissertation to investigate the main cause of the non-linearity observed by (1) developing a computerized mathematical scheme, based on a non-linear model, capable of evaluating parameters related to the energy dissipated then, (2) utilize this scheme to design (or analyze) structured surfaces, and (3) design an experiment validate this non-linear based model scheme. |
