1. Time Domain Simulation of Chatter Vibration in Drilling
- A one DOF model for simulating chatter vibration in drilling based on gyroscopic effect due to rotating of tool and effect of the damping characteristics of flank surface is investigated. The equation is simplified to an eigenvalue problem to find the limits of stability. MATLAB DDE Solver is used to simulate the tool motion. This model can determine hole form and because of the matrix form of the equation, different parameters can be added further to find a more accurate answer or examining other process damping applications. Although, cutting forces are assumed only in one direction, stability lobs had a good agreement with experimental data.
2. Optimizing Process Time in Deep Drilling
- Chatter vibration in deep drilling is investigated, and a model is prepared to define the effect of different cutting and tool geometry parameters on the stability lobs. Then a detailed discussion for finding ways of performing faster operation is done. Effect of step drilling on process time is determined, and then different process optimization methods due to these parameters are investigated, it was dividing process in to two stages, first stage using a shorter drill with higher feed rate and then using main drill with slower feed rate. It was shown that step drilling with different tool lengths is a good way to do the operation faster.