An Analysis of Plug Chatter in Fixed and Floating Plug Tube Drawing

Summary

The fixed and floating plug processes have been examined both analytically and experimentally in order to determine the conditions and parameters which control the onset of the plug chatter phenomena. It is shown that the “plug bar” stiffness is the major controlling factor in the process but other variables can be effective in initiating chatter. For fixed plugs it is the stick-slip mechanism which causes chatter whilst for the much stiffer floating plug system it is geometry factors which generally cause plug chatter. The importance of maintaining the correct tool geometry is clearly established and the results and observations are supported by industrial practice. The experimental observations and theoretical analysis can be extended to cover a wider range of D/t ratios than was considered in the experimental programme.