Development of constrained optimisation analyses and strategies for multi-pass rough turning operations

In this paper, the development of constrained optimisation analyses and strategies for selecting the optimum cutting conditions for multi-pass rough turning operations on CNC and conventional lathes is outlined and discussed. The analysis is based on the criterion typified by the maximum production rate and incorporates various relevant technological constraints. The approach adopted in arriving at the final solution involved a combination of theoretical economic trends and numerical search methods. popular multi-pass solution strategies such as using all equal passes or all equal passes except one pass are shown to be useful approximations but the final computer-aided optimal solutions yielded unequal cutting conditions per pass. Numerical case studies supported the importance of using developed optimisation strategies rather than handbook recommendations, and demonstrated the effects of major variables as well as the superiority of multi-pass over single pass production rates.