Evaluation of stressed state of coker reactor shell with plastic deformation

1986 ◽  
Vol 22 (7) ◽  
pp. 352-355 ◽  
Author(s):  
E. A. Filimonov ◽  
I. R. Kuzeev
1978 ◽  
Vol 10 (5) ◽  
pp. 565-568
Author(s):  
R. F. Merenkova ◽  
P. F. Koshelev ◽  
V. V. Grot

2017 ◽  
Vol 2 (3) ◽  
pp. 25-30 ◽  
Author(s):  
Семен Зайдес ◽  
Semen Zaides ◽  
Као Нго ◽  
Сao Ngo

The paper reports the results of the strengthening simulation process. A new kinematics of deforming rollers ensuring a surface plastic deformation of shafts of low rigidity was considered. On the basis of the theory of low elasto-plastic deforma-tions and a method of finite elements there were formed simulators of a strengthening process allowing the definition of a stressed state in a sample depending on the form and kinematics of an indenter. With the aid of ANSYSWB software there was considered the impact of some circuits of deformation upon a stressed state: running-in by rolling, running-in by slip, running-in by one and two rollers with the rotation with regard to a diametrical axis. On the basis of simulation results it was revealed that the basic factors affecting a stress-strain state of parts are geometry, a form, a mutual location of elements of a tool deformed and their kinematics with regard to a part worked.


2021 ◽  
Vol 11 (3) ◽  
pp. 267-272
Author(s):  
Vladimir Skripnyak ◽  
Kristina Iohim ◽  
Evgeniya Skripnyak ◽  
Vladimir Skripnyak

1991 ◽  
Vol 23 (10) ◽  
pp. 1039-1047 ◽  
Author(s):  
F. F. Giginyak ◽  
O. K. Shkodzinskii ◽  
A. A. Lebedev ◽  
V. T. Timofeev

Author(s):  
J. Temple Black

There are two types of edge defects common to glass knives as typically prepared for microtomy purposes: 1) striations and 2) edge chipping. The former is a function of the free breaking process while edge chipping results from usage or bumping of the edge. Because glass has no well defined planes in its structure, it should be highly resistant to plastic deformation of any sort, including tensile loading. In practice, prevention of microscopic surface flaws is impossible. The surface flaws produce stress concentrations so that tensile strengths in glass are typically 10-20 kpsi and vary only slightly with composition. If glass can be kept in compression, wherein failure is literally unknown (1), it will remain intact for long periods of time. Forces acting on the tool in microtomy produce a resultant force that acts to keep the edge in compression.


Author(s):  
L. Andrew Staehelin

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.


Author(s):  
J. Temple Black

The output of the ultramicrotomy process with its high strain levels is dependent upon the input, ie., the nature of the material being machined. Apart from the geometrical constraints offered by the rake and clearance faces of the tool, each material is free to deform in whatever manner necessary to satisfy its material structure and interatomic constraints. Noncrystalline materials appear to survive the process undamaged when observed in the TEM. As has been demonstrated however microtomed plastics do in fact suffer damage to the top and bottom surfaces of the section regardless of the sharpness of the cutting edge or the tool material. The energy required to seperate the section from the block is not easily propogated through the section because the material is amorphous in nature and has no preferred crystalline planes upon which defects can move large distances to relieve the applied stress. Thus, the cutting stresses are supported elastically in the internal or bulk and plastically in the surfaces. The elastic strain can be recovered while the plastic strain is not reversible and will remain in the section after cutting is complete.


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