Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : plasticity

Experimental Study of Steady-State Tube Expansion by using Conical Mandrel

Tahseen Taha Othman; Hazim Khalil Khalaf; Jalal Khorshed Alyan

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 148-166

An Experimental study Conducted for the continuous expansion process of the brass (70/30) tubes by pushing a conical rigid mandrel inside the tube mechanically.
This study included an empirical part throughout the test of (60) tube samples to give a different expanding ratios up to (40%) and almost at semi-cone angle of the mandrel ranging from small, medium and large angles (10°,20° and 30°) in addition to that the samples with different relative thicknesses (0.05, 0.1, 0.15 and 0.2).The theoretical part ensures that for the predicted with relative forming stress that needed to complete the expansion process in addition to the changes in the stresses of the various exposed a wall of the sample tube ,The study included the influence of work hardening property which earns this study has a great importance in how to deal with this property. This study showed a good agreement between both theoretical and practical parts, especially in determining the relative forming stress necessary for the success of the operation that showed the relative forming stress increases as the expansion ratio and the semi-cone angle of the mandrel increases has ranged between (0.1-0.7) of the samples tested. Noting that the formation is influenced by the first was much larger than the second was. Whereas the relative forming stress decrease as the relative thickness increase for the same expansion ratio and the semi-cone angle of the mandrel formation.

Plane Flow Analysis for a Profile Extrusion Die Using Digital Image processing Technique

Salah K. Jawad; Ali Abbar Khleif; Mohanad Q. Abbood

Engineering and Technology Journal, 2012, Volume 30, Issue 9, Pages 1562-1581

This paper investigates the applicability of the proposed digital image
correlation (DIC) system instead of traditional method by microscope to
measure the strains in forward extrusion process, which conducted for
rectangular section with plane strain condition by using taper die at angle
(2 = 90 ̊) and the proportion of reduction in area is (42.85 %).
Commercial pure lead (99.99% Pb) was chosen as a typical pattern to
measure the strain and strain rate for the forward extrusion process by a
visio-plasticity technique and the proposed digital image correlation
system. The obtained results indicate that the proposed digital image
correlation (DIC) system is an accurate and reliable for measuring the
strains using inexpensive equipments