Three-Dimensional Strain Field for a Hot Rolled Billet by Photoplastic Simulation

Strain Distribution During Hot Rolling of Strip by Photoplastic Simulation

“…They used a material developed by Morris and Ri ley [25J and rolled a number of billets of different dimensf.ons in an attempttosimulate the hot-rolling process. Their results demonstrated that photoplasticity can be used to find the whole field strain distribution in bi Ilets.Further work in this direction was reported by Burger, EI-Hout and Gomide [26] . Theyap plied photoplastic technique to evaluated the three-dimensional strain fT eld of a rolled billet w.Lth a particular geometry.…”

“…In a different approach to the problem several experimental attempts have been made to evaluate the three-dimensional strain distribution in hot-form ing processes using photoplastic techniques [22][23][24][25][26][27] . The approach is based on the permanent birefringence that remains locked into a photoplastic mate rial after large plastic deformation.…”

Photoplastic studies of upset forging of rings and of strip rolling

“…As a consequence, the 100% Laminae was selected for all sub sequent studies [33,34,77]. To date, however, no attempts were made to determine the influence of the relaxation on the locked in flow patterns of the material when it is tested.…”

“…Poisson's ratio must have the same value for modeland prototype in the plastic range.4.The "yield criteria" and flow rules must be the same for both materials.The last three of these conditions will be discussed in turn to establish whether the 100% rigid Laminae is acceptable for predicting gross plastic deformations in hot forming operations on aluminum. Aluminum was chosen as a prototype material because it has wide application in the metal forming industry and because recent research[27,31,77] have indi cated reasonable correlation between the deformations of hot aluminum and Laminae resins. The research for this disserta tion did not attempt to test any Laminae resin other than the 100% rigid mixture.In order to verify the second condition, dimensionless true stress-true strain curves were plotted from the result obtained for uniaxial compression of small cylinders (see…”