A Study of Fixture Layout and Clamping Force for a Ti-6Al-4V Disk in a Vertical Turning Lathe Numerically Controlled Machine Maureen Fang Sept 17, 2009
Overview Vertical Turning Lathe (VTL) Machine Fixture-Disk Assembly Cutting Forces Finite Element Models in ANSYS Initial Fixture Layout Deflections within Disk Questions
Vertical Turning Lathe (VTL) Machine
Fixture-Disk Assembly Clamp Plate Disk Inner Diameter=0.457m (18 in) Outer Diameter=0.508m (20 in) Height=0.0508m (2 in) Locator
Machining an Outer Diameter Cutting Tool
Cutting Forces Orientations
Cutting forces calculation Flow Diagram
Input Variables Tool Geometry Machining Parameters
Cutting Forces Results are generated by Matlab codes for both oblique and orthogonal cutting Orthogonal cutting has only two cutting forces components Tangential force is the dominate component. Tangential Force Orthogonal Cutting
Finite Element Model in ANSYS Number of elements32000 Number of Nodes38720 Degree of Freedom per Node6 Type of ElementsBrick Material of Workpiece Ti-6Al- 4V Modulus of Elasticity110 GPa Poisson Ratio0.34
Deflections during a complete cut The “U” shape curve presents the magnitude of deflection changes as the cutting tool travels from the top to the bottom surface of the disk. The displacement vector sum is largest at the top. The subsequent models will have the cutting forces applied at the top surface.
Initial Fixture Layout
Circumferential locations Circumferential locations of one set of clamp and locator with respect to cutting forces
Displacement Vector Sum A B C
Displacement Components Z-component = axial direction Y-component = circumferential direction
Contour Plots from ANSYS
Questions