Genetic Optimisation of Machine Tool Paths
Many aircraft components are designed from monolithic structures to reduce manufacturing cost, reduce weight, and increase stiffness. To enable machining of such structures it is necessary to perform high-speed machining that can remove a large amount of material within a shorter time. However, the performance of high speed-machining operations is limited by the static and dynamic stiffness of the tool and part, which can cause problems such as regenerative chatter and push-off.
The tool path plays a key role in avoiding these problems as it helps to minimise the workpiece vibration during machining. This work aims to optimise the tool path by simulating the removal of material in a finite element environment, which is controlled by a Genetic Algorithm. To simulate the physical removal of material during machining, a finite element model is designed to represent a thin walled workpiece. The target was to reduce the deflection after each element was removed, according to the sequence suggested by the Genetic Algorithm.
As a first step, a cantilever beam is created, meshed and numbered. There are 6 elements to remove, representing the tool path sequence for a physical machining process. A Genetic Algorithm was used to find the element removal sequence that gave the greatest workpiece stiffness in the cutting region. It is concluded that tool path optimisation can be performed successfully by the proposed technique.
KeywordsGenetic Algorithm Tool Path Travelling Salesman Problem Chip Thickness Uncut Chip Thickness
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