عنوان مقاله [English]
In the boring process with length to diameter ratio more than four, due to low rigidity of the tool, a lot of vibration is caused and the machining quality of the surface is reduced. For this reason, controlling and reducing vibration of the tool is always important. In this paper, the lateral vibration of a long boring bar equipped with dynamic absorber and the effect of various parameters are investigated. For this purpose, first the governing equations of the system are extracted and solved using assumed mode method. Then, the effect of absorber presence and its parameters such as absorber position, absorber stiffness and absorber length on the vibration of tool are studied and results are presented in diagrams. The results show that the addition of absorber increases the natural frequency of tool by 10% and as the absorber gets closer to the tip, the performance of boring process increases. Also, as the stiffness of the absorber increases, the steady-state cutting range of the boring bar increases and the tool begins to vibrate at higher frequencies. In addition, by increasing absorber length up to 175 mm, the distance between the two absorber resonance frequencies increases, which indicates an increase in the range of stable cutting and dynamic stiffness, and also from lengths greater than 175 mm, this behavior decreases.