In this research, flat rolling process of bonded sandwich sheets is investigated by the method of upper bound. A kinematically admissible velocity field is developed for a single layer sheet and is extended into the rolling of the symmetrical sandwich sheets. The internal, shear and frictional power terms are derived and they are used in the upper bound model. Through the analysis, the rolling ...

In this paper, a mathematical model for symmetrical multi-layer sheet rolling, in which the layers are unbounded before rolling, by using the upper bound method and stream function theorem is proposed. Using this model, we can investigate the plastic deformation behavior of sheets at the roll gap during rolling. Effect of various rolling conditions such as initial and final thickness and flow s...

Asymmetrical shear rolling with velocity asymmetry and geometry asymmetry is beneficial to enlarge deformation and refine grain size at the center of the thick plate compared to conventional symmetrical rolling. Dynamic recrystallization (DRX) plays a vital role in grain refinement during hot deformation. Finite element models (FEM) coupled with microstructure evolution models and cellular auto...

Rolling is one of the most employed industrial processes which can be used at multiple manufacturing stages, allowing different geometries such as plates, rods, profiles, billets, slabs, tubes, and seamless tubes to obtained. However, rolled products develop anisotropy due preferential orientation crystals in rolling direction. Thus, some process configurations processing parameters (e.g., thic...

there is a complicated relation between cold flat rolling parameters such as effective input parameters of cold rolling, output cold rolling force and exit thickness of strips. in many mathematical models, the effect of some cold rolling parameters has been ignored and the outputs have not a desirable accuracy. in the other hand, there is a special relation among input thickness of strips, the ...

background: symmetrical peripheral gangrene is usually associated with underlying medical problems and it is seldom seen in pregnancy. sepsis though common in a setting of delivery by unskilled midwife is rarely accompanied by symmetrical gangrene. case presentation: we report a case of symmetrical peripheral gangrene which occurred in the winter, triggered possibly by sepsis and a single dose ...

the forging model for cold rolling is one of rolling models that is used in rolling calculations. in this model,the final rolling pressure is an average value and it is not an accurate model.also by using this model,the firction hill curves are plotted due to the central point of the rolling bite length while frictional stresses intersect at the neutral point.in this study, a new model based on...

strip tearing during cold rolling process has always been considered among the main concerns for steel companies. several works have been done so far regarding the examination of the issue. in this paper, experimental data from cold rolling tandem mill is used for detecting strip tearing. sensors are placed across the cold rolling tandem mill. they receive information on parameters (such as ang...

cold rolling process of a major transformation in the form of sheet metal and a wide range of steel products are produced in this way. elastic deformation during cold rolling working rollers and the inevitable increase in the rolling force. in this study, the effect of elastic deformation during cold rolling mill rollers working on the reciprocating back and forth in tandem with the presence of...