Abstract
Three-axis computer numerical control machining centers are commonly used in machining due to their simple operations. When machining curved surfaces, the 3-axis CNC machining centers use interpolation line segment to fit the curved surfaces. The quality of the machined surface is affected by the length of the interpolation line segment. Sharp corners are formed at the junction of straight segments. The appearance of sharp corners will lead to increased stress concentration. To study the relationship between machined surface quality and interpolation straight line, this paper establishes the mathematical model of surface topography in ball-end milling multi-curved surfaces by a 3-axis milling center with considering the acceleration and deceleration controls. Based on the surface topography model, the stress concentration factor is analyzed in machining curved surfaces with different lengths of interpolation lines. The results show that the stress concentration factor decreases with the increase of the central angle when the length of interpolation lines and the radius of curvature are kept in constant, while decreases with the increase of the radius of curvature when the length of the interpolation lines and the central angle are held on. Moreover, the stress concentration factor increases as the length of the interpolation lines increases when the radius of curvature and the central angle are kept in constant. A method for selecting proper length of interpolation lines based on the stress concentration is proposed. In addition, the quality of the machined surfaces can be improved through the optimization of the tool path.
Highlights
Based on the surface topography model, the surfaces stress concentration factor analysis is carried out in machining curved surfaces with variable curvatures with different lengths of interpolation lines
The results show that when the length of interpolation lines and the radius of curvature are kept constant, the stress concentration factor decreases with the increase of the central angle
When the central angle and the length of the interpolation lines are kept constant, the stress concentration factor decreases with the increase of radius of curvature
Summary
Use MATLAB software as a tool to simulate coordinates of any cutting point on the cutting surface appearance. Import the machined surfaces model into the WORKBENCH, and define the properties of the material. In MATLAB, the coordinate points of the perpendicular to the tangent lines at the joint of simulated surfaces are extracted. Use the the interpolation lines and points to the center of command stream instructions in ANSYS to the curve. Change the length of the interpolation lines, simulation parameters are shown in Tab 2.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
