Three-dimensional analysis of edge rolling based on dual-stream function velocity field theory

2012 ◽

Vol 500 ◽

pp. 410-413

Author(s):

Akshaya Kumar Rout ◽

Kali Pada Maity

Keyword(s):

Velocity Field ◽

Stream Function ◽

Function Method ◽

Fem Analysis ◽

Extrusion Process ◽

Extrusion Pressure ◽

Upper Bound Method ◽

Die Profile ◽

Deform 3D ◽

Dual Stream Function

The linearly converging die plays a significant role in the extrusion process of section products in terms of reduction in extrusion load and improvement of product quality. With the help of upper bound method based on dual stream function method. Very few investigations have been reported when product and billet geometry are dissimilar using linear converging die. Dual stream function method is incapable of predicting kinematically admissible velocity field in the above case, SERR technique (Spatial Elementary Rigid Region) is the only alternative. In the present investigation, a reformulated SERR technique has been used to determine non-dimensional extrusion pressure and optimum die profile both for frictionless and friction conditions. SERR technique based on discontinuous velocity field is applicable for this case. In the present investigation, non-dimensional extrusion pressure and optimum die length has been determined for extrusion of pentagonal from round billet and the results are compared with the FEA results by using DEFORM 3D.

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Slab analysis based on stream function method in chamfer edge rolling of ultra-heavy plate

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406216646400 ◽

2016 ◽

Vol 231 (7) ◽

pp. 1237-1251

Author(s):

JG Ding ◽

HY Wang ◽

DH Zhang ◽

DW Zhao

Keyword(s):

Velocity Field ◽

Stream Function ◽

Function Method ◽

Rolling Force ◽

Yield Criterion ◽

Three Dimensional ◽

Total Power ◽

Shape Coefficient ◽

Heavy Plate ◽

Dog Bone

In this paper, three-dimensional velocity field is proposed by means of stream function method with bisecting yield criterion in chamfer edge rolling of ultra-heavy plate. Parabolic dog-bone shape function is derived so as to obtain velocity field with fixed angle of chamfer edge by stream function method, dog-bone shape coefficient η can be derived from volume invariant condition, and then the plastic deformation power, shear power as well as friction power are obtained respectively with the bisecting yield criterion. Summing up the power contributions, total power functional is presented, from which minimum value can be obtained by searching method, and vertical rolling force and torque are also finally obtained. The predictions of roll force and torque are compared with different angles of chamfer edge as well as different plate thicknesses. The results are shown to be in a very good agreement with the analytical and experimental results.

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In situ investigation of the primary recrystallization of alpha titanium in HVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100110313 ◽

1978 ◽

Vol 36 (1) ◽

pp. 634-635

Author(s):

S. Naka ◽

R. Penelle ◽

R. Valle

Keyword(s):

Dimensional Analysis ◽

Texture Evolution ◽

Cold Work ◽

Three Dimensional ◽

Primary Recrystallization ◽

Thin Foils ◽

In Situ Investigation ◽

Grain Growth Model ◽

Alpha Titanium

The in situ experimentation technique in HVEM seems to be particularly suitable to clarify the processes involved in recrystallization. The material under investigation was unidirectionally cold-rolled titanium of commercial purity. The problem was approached in two different ways. The three-dimensional analysis of textures was used to describe the texture evolution during the primary recrystallization. Observations of bulk-annealed specimens or thin foils annealed in the microscope were also made in order to provide information concerning the mechanisms involved in the formation of new grains. In contrast to the already published work on titanium, this investigation takes into consideration different values of the cold-work ratio, the temperature and the annealing time.Two different models are commonly used to explain the recrystallization textures i.e. the selective grain growth model (Beck) or the oriented nucleation model (Burgers). The three-dimensional analysis of both the rolling and recrystallization textures was performed to identify the mechanismsl involved in the recrystallization of titanium.

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