Creep Modeling in a Composite Rotating Disc with Constant Thickness in the Presence of Residual Stress

2020 ◽  
pp. 191-213
Author(s):  
Nishi Gupta ◽  
Satya Bir Singh
Keyword(s):  
Residual Stress ◽  
Constant Thickness ◽  
Rotating Disc

Finishing Methods of Tools Functional Surfaces

2013 ◽  
Vol 581 ◽  
pp. 18-21
Author(s):  
Imrich Lukovics ◽  
Jiří Čop
Keyword(s):  
Residual Stress ◽  
Cutting Tools ◽  
Grinding Wheels ◽  
Rotating Disc ◽  
Functional Surfaces ◽  
Machining Speed

Article shows the calculation of the stress in a rotating disc and the possibility of using proprietary forms of instruments for speed grinding. It presents the results of speed and efficient cutting tools in machining these materials alloyed with chromium. In addition, it notes the results of the influence of technological conditions on the quality of surfaces, the residual stress in the workpiece, resulting from the machining speed and the influence of technological conditions on the wear of grinding wheels. Finally, some options for the use of finishing techniques in practice are mentioned.

Compressive residual stress field in functionally graded material rotating disc under thermo-mechanical loading

2017 ◽  
Vol 36 (17) ◽  
pp. 1239-1253
Author(s):  
Kaveh Oghbaei ◽  
Hamid Ekhteraei Toussi
Keyword(s):  
Residual Stress ◽  
Mechanical Loading ◽  
Functionally Graded Material ◽  
Compressive Residual Stress ◽  
Kinematic Hardening ◽  
Functionally Graded ◽  
Stress Fields ◽  
Elastic Behavior ◽  
Rotating Disc ◽  
Graded Material

Residual stress fields in functionally graded material rotating disc under thermo-mechanical loading is obtained by using the variable material properties method. The mixture model of Tamura–Tomato–Ozawa is used to correlate the overall mechanical behavior to the behavior of the constitutive phases in the construction of a rotating disc. The elastic-linearly kinematic hardening plastic material model is used for the metallic phase and a linear perfectly elastic behavior is assumed for the ceramic part. A finite element method analysis by using ABAQUS software is performed to assess the validity of the proposed method. The effect of velocity and temperature on the residual stress fields are studied. A study also worked out to see the effect of different parameters upon the residual stress fields. The effect of reverse yielding on the transposition of the compressive residual stress zone is investigated.

EFFECT OF RESIDUAL STRESS AND REINFORCEMENT GEOMETRY IN AN ANISOTROPIC COMPOSITE ROTATING DISC HAVING VARYING THICKNESS

2012 ◽  
Vol 01 (04) ◽  
pp. 1250035
Author(s):  
VANDANA GUPTA ◽  
S. B. SINGH
Keyword(s):  
Residual Stress ◽  
Steady State ◽  
Creep Behavior ◽  
Yield Criterion ◽  
Steady State Creep ◽  
Thermal Residual Stress ◽  
Rotating Disc ◽  
Varying Thickness ◽  
Creep Analysis ◽  
Sic Particle

The influence of the thermal residual stress and reinforcement geometry on the creep behavior of a composite disc has been analyzed in this paper. The creep analysis in a rotating disc made of Al-SiC (particle/whisker) composite having hyperbolically varying thickness has been carried out using anisotropic Hoffman yield criterion and results obtained are compared with those using Hill's criterion ignoring difference in yield stresses. The steady state creep behavior has been described by Sherby's creep law. The creep parameters characterizing difference in yield stresses have been used from the available experimental results in literature. It is observed that the stresses are not much affected by the presence of thermal residual stress, while thermal residual stress introduces significant change in the strain rates in an anisotropic rotating disc. Secondly, it is noticed that the steady state creep rates in whisker reinforced disc with/without residual stress are observed to be significantly lower than those observed in particle reinforced disc with/without residual stress. It is concluded that the presence of residual stress in an anisotropic disc with varying thickness needs attention for designing a disc.

Consideration of damage in the analysis of autofrettage of thick-walled pressure vessels

2016 ◽  
Vol 230 (20) ◽  
pp. 3585-3593 ◽  
Author(s):  
H Altenbach ◽  
GI Lvov ◽  
K Naumenko ◽  
V Okorokov
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Bauschinger Effect ◽  
Pressure Vessels ◽  
Stress Fields ◽  
Constant Thickness ◽  
Process Conditions ◽  
Material Damage ◽  
Damage Processes ◽  
Walled Cylinder

In this study, the influence of material damage and the Bauschinger effect on the autofrettage of thick-walled pressure vessels is investigated. Constitutive equations for the elasto-plastic deformation and damage processes are presented. Boundary value problems for a thick-walled cylinder and for a thick-walled sphere of constant thickness are formulated. Computations are preformed to find the optimum autofrettage pressure, for which the equivalent stresses in the vessel take the minimum value under process conditions. Furthermore, residual stress fields after the autofrettage are analyzed. The results show that the Bauschinger effect and damage lead to essential reduction of favorable residual stresses.

scholarly journals Creep Modeling in a Composite Rotating Disc with Thickness Variation in Presence of Residual Stress

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Vandana Gupta ◽  
S. B. Singh
Keyword(s):  
Residual Stress ◽  
Steady State ◽  
Creep Behavior ◽  
Yield Criterion ◽  
Steady State Creep ◽  
Thickness Variation ◽  
Stress And Strain ◽  
Rotating Disc ◽  
Varying Thickness ◽  
Von Mises

Steady-state creep response in a rotating disc made of Al-SiC (particle) composite having linearly varying thickness has been carried out using isotropic/anisotropic Hoffman yield criterion and results are compared with those using von Mises yield criterion/Hill's criterion ignoring difference in yield stresses. The steady-state creep behavior has been described by Sherby's creep law. The material parameters characterizing difference in yield stresses have been used from the available experimental results in literature. Stress and strain rate distributions developed due to rotation have been calculated. It is concluded that the stress and strain distributions got affected from the thermal residual stress in an isotropic/anisotropic rotating disc, although the effect of residual stress on creep behavior in an anisotropic rotating disc is observed to be lower than those observed in an isotropic disc. Thus, the presence of residual stress in composite rotating disc with varying thickness needs attention for designing a disc.

High-angle electron scattering from amorphous silicon

1995 ◽  
Vol 53 ◽  
pp. 162-163
Author(s):  
M. Libera ◽  
J.A. Ott ◽  
K. Siangchaew ◽  
L. Tsung
Keyword(s):  
Electron Scattering ◽  
Amorphous Material ◽  
Structural Defects ◽  
Constant Thickness ◽  
High Angle ◽  
Fast Electrons ◽  
Angle Scattering ◽  
Stem Image ◽  
Amorphous Si ◽  
Thermal Vibrations

Channeling occurs when fast electrons follow atomic strings in a crystal where there is a minimum in the potential energy (1). Channeling has a strong effect on high-angle scattering. Deviations in atomic position along a channel due to structural defects or thermal vibrations increase the probability of scattering (2-5). Since there are no extended channels in an amorphous material the question arises: for a given material with constant thickness, will the high-angle scattering be higher from a crystal or a glass?Figure la shows a HAADF STEM image collected using a Philips CM20 FEG TEM/STEM with inner and outer collection angles of 35mrad and lOOmrad. The specimen (6) was a cross section of singlecrystal Si containing: amorphous Si (region A), defective Si containing many stacking faults (B), two coherent Ge layers (CI; C2), and a contamination layer (D). CBED patterns (fig. lb), PEELS spectra, and HAADF signals (fig. lc) were collected at 106K and 300K along the indicated line.

TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

1994 ◽  
Vol 52 ◽  
pp. 628-629
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Residual Stress ◽  
Single Phase ◽  
Stress Relief ◽  
Stress Recovery ◽  
Surface Residual Stress ◽  
Microscopic Mechanism ◽  
Sic Particles ◽  
Annealing Procedure ◽  
The Difference ◽  
Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

Residual stress measurements and modeling of built-up Box-T sections

2021 ◽  
Vol 160 ◽  
pp. 107336
Author(s):  
Ziqian Zhang ◽  
Gang Shi ◽  
Xuesen Chen ◽  
Lijun Wang ◽  
Le Zhou
Keyword(s):  
Residual Stress ◽  
Stress Measurements
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