Engineering and Technology Journal

The non-conventional spinning process was adopted for producing polygons, but one of the process limitations is the error between design and the final product especially with no-mandrel. Dimensional accuracy was adopted for this purpose which gives an indicator of the ability of the formed part to matches the design and checking validated of the adopted methodology for producing rectangular cross-section spun parts, by comparing the coordinating points of real part with the points of the design model. The point of a real part was measured by using a sphere probe fixed on the three-axis milling machine and capturing the data of machine axis movements for the center location of the probe, also, the measurements oppositely took place, by offsetting the points of design along the normal vector for comparison with the real part points. Three parameters were invested for study the effects on the dimensional accuracy, these parameters are spindle speed (48, 68, and 135 RPM), feed ratio (0.16, 0.22, and 0.32 mm/rev), and the ball diameter of the forming tool (16, 22 and 25 mm). The results show that tool ball diameter mainly affecting dimensional accuracy with a higher value of average error reach (6.47mm) when 16mm diameter of tool ball was used, on the other hand, the minimum average error was 1.705mm at low spindle speed.

Simulation of metal forming processes using the Finite Element Method (FEM) is a well-established procedure, being nowadays possible to develop alternative approaches, such as inverse methodologies, in solving complex problems. This study investigated the effect of orientation and pre-tension on stresses distribution numerically by software ANSYS 19 using the finite element method. The pre-tension is 55% from total strained in each rolling direction. The results show that the orientation has a significant effect on stresses distribution and stress value before and after pre-tension 55%. Although there is a regular distribution of stresses in three direction, but there is significant difference in the values of stresses in each of (0, 45, 90) degrees. The highest value of t rolling direction. The pre-tension has a greater impact on stresses distribution and stress value. Although, there is a regular distribution of stresses in blank before and after pre-tension, but there is significant difference in the values. Where in 0 degree on rolling direction the stresses increased by 31.7% from their values before pre-tension, while in 45 degrees on rolling direction the stresses increased by 35.6% and in 90 degrees on rolling direction the stresses increased by 23.6% from their values before pre-tension.