scholarly journals A lower bound solution for the plane strain extrusion forging process

1988 ◽  
Vol 11 ◽  
pp. 1183-1188 ◽  
Author(s):  
M.S.J. Hashmi
Keyword(s):  
Lower Bound ◽  
Plane Strain ◽  
Forging Process ◽  
Bound Solution ◽  
Lower Bound Solution

Lower Bounds to the Collapse Load of a Thick Circular Cylinder Subjected to Internal Pressure and Shear

1977 ◽  
Vol 44 (4) ◽  
pp. 766-768
Author(s):  
N. Inoue ◽  
H. Nakagawa ◽  
T. Nakayama ◽  
M. Shimono ◽  
T. Tanaka
Keyword(s):  
Lower Bound ◽  
General Solution ◽  
Circular Cylinder ◽  
Internal Pressure ◽  
Plane Strain ◽  
Lower Bounds ◽  
Mathematical Theory ◽  
Collapse Load ◽  
Bound Solution ◽  
Lower Bound Solution

A new method for obtaining statically admissible states of stress in plane strain in the mathematical theory of plasticity is presented. After deriving a general solution, the proposed procedure is exemplified by a known solution of a thick circular cylinder subjected to internal pressure. The method is applied to a thick circular cylinder subjected to internal pressure and shear, and a lower-bound solution is given.

Stress discontinuities in plane plastic flow

1967 ◽  
Vol 2 (1) ◽  
pp. 52-61 ◽  
Author(s):  
F Ellis
Keyword(s):  
Lower Bound ◽  
Plane Strain ◽  
Plastic Flow ◽  
Constant Stress ◽  
Stress Fields ◽  
Bound Solution ◽  
Plane Plastic ◽  
Axis Of Symmetry ◽  
Lower Bound Solution

Statically admissible stress fields consisting of regions of constant stress in a state of incipient plastic flow separated by stress discontinuities form a powerful tool for obtaining lower bound solutions to problems in plane plastic flow. The properties of discontinuities which meet on an axis of symmetry are investigated and it is shown that solutions exist for ‘reflections’ of the discontinuity at the axis at angles of π/4 and 3π/4 as well as the angle π/2 hitherto assumed to be the only solution. The results are used to obtain a lower bound solution for plane-strain extrusion with reduction ratios less than 3:1.

scholarly journals Lower Bound Solution of Foundation Bearing Capacity beneath Strip Footing Based on Parabolic Mohr Failure Criterion

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Fang Wei ◽  
Shi Li-jun
Keyword(s):  
Lower Bound ◽  
Stress Field ◽  
Bearing Capacity ◽  
Yield Criterion ◽  
Rock Foundation ◽  
Allowable Stress ◽  
Bound Solution ◽  
Loading Tests ◽  
Lower Bound Solution ◽  
Two Parameter

The static allowable stress field of foundation under strip foundation is constructed by means of stress columns, and the calculation method of the lower bound foundation bearing capacity based on the two-parameter parabolic Mohr yield criterion is proposed. Moreover, the influence of the amount of stress columns and material mechanical parameters on the lower bound bearing capacity is analyzed. The results show that a better solution can be obtained by optimizing the static allowable stress field. However, the improvement of lower bound solution might be inefficient if the stress column amount is large enough. The stresses of the superimposition area show a reduction with the improvement of stress field; on the other hand, the superposed stresses are enhanced ever faster as the involved stress column increases. The tensile-compressive strength ratio has a moderate effect on the lower bound solution. Finally, the reliability of the proposed method is verified by some rock foundation loading tests.

scholarly journals Metal drawing goodness degree to which the Hollomon equation applies

2014 ◽  
Vol 20 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Živko Jokovic ◽  
Nina Djapic
Keyword(s):  
Lower Bound ◽  
Tungsten Carbide ◽  
Wire Drawing ◽  
Control Group ◽  
Practical Application ◽  
Theoretical Methods ◽  
Bound Solution ◽  
Cold Wire ◽  
Lower Bound Solution ◽  
Hollomon Equation

In order to establish the cold wire drawing production, the CuNi2Si alloy passes schedule were examined by the Duckfield and Ermanok methods in two wire drawing versions: with the diamond die with an angle of 9o and the tungsten carbide die with an angle of 7o . Experiments confirmed that the CuNi2Si alloy can be successfully transformed to the wire with the diameter of 0.2 mm with properties enabling its practical application. The experimental results and the control group showed that the theoretical methods of the upper and lower bound solution can determine the values of the relevant cold wire drawing factors for the CuNi2Si alloy to which Hollomon curve applies. 

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