Modeling of drill bit transverse vibrations


Tekinalp O., Ulsoy A. G.

Proceedings of SPIE - The International Society for Optical Engineering, vol.955, pp.129-134, 1988 (Scopus) identifier

Abstract

Drill bit natural frequencies and mode shapes are investigated using holographic interferometry techniques. For these experiments a fixture is developed to simulate some of the most important process parameters. The drill bit is fixed using an actual drill holder, and a hole drilled by the given drill bit. Then it is loaded to a nominal thrust force typical of machining. The structure is then excited using a piezoelectric exciter at various natural frequencies. The mode shapes of the drill bit are recorded on a photographic plate. The results of the experiments are then utilized toward the development of an analytical model. The model is a twisted Euler-Bernoulli beam subjected to thrust force and trasverse cutting forces. It also includes the rotation of the drill bit. The analytical model is solved using finite element techniques. The results from the holographic experiments are then compared to the numerical results obtained from the finite element analysis, and good agreement is observed. The validated finite element model is potentially useful for design and process optimization in drilling, as well as for process control. © 1988, SPIE.