scholarly journals Creep transition stresses in a thin rotating disc with shaft by finite deformation under steady-state temperature

2010 ◽  
Vol 14 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Thakur Pankaj
Keyword(s):  
Thermal Effect ◽  
Radial Stress ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Angular Speed ◽  
Incompressible Material ◽  
Strain Rates ◽  
Rotating Disc ◽  
Maximum Value ◽  
Steady State Temperature

Creep stresses and strain rates have been derived for a thin rotating disc with shaft at different temperature. Results have been discussed and presented graphically. It has been observed that radial stress has maximum value at the internal surface of the rotating disc made of incompressible material as compared to circumferential stress and this value of radial stress further increase with the increase of angular speed. With the introduction of thermal effect, it has been observed that radial stress has higher maximum value at the internal surface of the rotating disc made of incompressible material as compared to circumferential stress, and this value of radial stress further increases with the increase of angular speed as compared to the case without thermal effect. Strain rates have maximum values at the internal surface for compressible material. Rotating disc is likely to fracture by cleavage close to the inclusion at the bore.

scholarly journals Systematic Review Based on the Study of Elastic-Plastic Transition Stresses

2021 ◽  
Vol 23 (07) ◽  
pp. 1077-1084
Author(s):  
Gurinder Kaur ◽  
◽  
Nishi Gupta ◽  
Keyword(s):  
Systematic Review ◽  
Thermal Effect ◽  
Radial Stress ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Angular Speed ◽  
Plastic State ◽  
Compressible Material ◽  
Rotating Disc ◽  
Elastic Plastic

A systematic review based upon the study of elastic-plastic transition stresses. A worthwhile work about the analysis of elastic-plastic transition stresses in different rotating materials by varying different parameters is discussed. In the case of compressible material, the strain rates have a maximum value at the internal surface. It has been observed that radial stress has a higher value at the internal surface of the rotating disc made of incompressible material as compared to circumferential stress with thermal effect and this value of radial stress further increases. With the increase of angular speed, the value of radial stress further increases as compared to the case with no thermal effect. The magnitude of the stresses and pressure reduce with the variation of thickness needed for a fully plastic state. At the inner surface, the effect of heat increases stress for compressible material. The thickness and density parameters decrease the value of angular speed at the internal surface of the rotating disc of compressible material as well as incompressible materials. The radial and the hoop stress, both decrease with the increased value of temperature at the Elastic-Plastic stage, but with the reverse result obtained for a fully Plastic state.

scholarly journals Thermo elastic-plastic transition in a thin rotating disc with inclusion

2007 ◽  
Vol 11 (1) ◽  
pp. 103-118 ◽  
Author(s):  
Kumar Gupta ◽  
P Pankaj
Keyword(s):  
Thermal Effect ◽  
Internal Surface ◽  
Angular Speed ◽  
Incompressible Material ◽  
Plastic State ◽  
Percentage Increase ◽  
Compressible Material ◽  
Rotating Disc ◽  
Elastic Plastic ◽  
Different Temperatures

Stresses for the elastic-plastic transition and fully plastic state have been derived for a thin rotating disc with shaft at different temperatures and results have been discussed and depicted graphically. It has been observed that the rotating disc with inclusion and made of compressible material requires lesser angular speed to yield at the internal surface and higher percentage increase in angular speed to become fully plastic as compare to disc made of incompressible material. With the introduction of thermal effect the rotating disc with inclusion required lesser angular speed to yield at the internal surface. Rotating disc made of compressible material with inclusion requires higher percentage increase in angular speed to become fully-plastic as compare to disc made of incompressible material. Thermal effect also increases the values of radial and circumferential stresses at the internal surface for fully-plastic state. .

Thermal creep transition stresses and strain rates in a circular disc with shaft having variable density

2016 ◽  
Vol 33 (3) ◽  
Author(s):  
Dr Pankaj Thakur ◽  
Jatinder Kaur ◽  
Satya Bir Singh
Keyword(s):  
Thermal Effect ◽  
Radial Stress ◽  
Design Methodology ◽  
Internal Surface ◽  
Variable Density ◽  
Thermal Creep ◽  
Transition Theory ◽  
Circular Disc ◽  
Strain Rates ◽  
Rotating Disc

Purpose The purpose of this paper is to present study of thermal creep stresses and strain rates in a circular disc with shaft having variable density by using Seth’s transition theory. Design/methodology/approach Seth’s transition theory is applied to the problem of thermal creep transition stresses and strain rates in a thin rotating disc with shaft having variable density by finite deformation. Neither the yield criterion nor the associated flow rule is assumed here. The results obtained here are applicable to compressible materials. If the additional condition of incompressibility is imposed, then the expression for stresses corresponds to those arising from Tresca yield condition. Findings Thermal effect increased value of radial stress at the internal surface of the rotating disc made of incompressible material as compared to tangential stress and this value of radial stress further much increases with the increase in angular speed as compared to without thermal effect. Strain rates have maximum values at the internal surface for compressible material. Originality/value The model proposed in this paper is used in mechanical and electronic devices. They have extensive practical engineering application such as in steam and gas turbines, turbo generators, flywheel of internal combustion engines, turbojet engines, reciprocating engines, centrifugal compressors and brake disks.

scholarly journals Elastic-plastic transition stresses in a thin rotating disc with rigid inclusion by infinitesimal deformation under steady-state temperature

2010 ◽  
Vol 14 (1) ◽  
pp. 209-219 ◽  
Author(s):  
Thakur Pankaj
Keyword(s):  
Outer Surface ◽  
Room Temperature ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Angular Speed ◽  
Incompressible Material ◽  
Plastic State ◽  
Rotating Disc ◽  
Elastic Plastic ◽  
Different Temperatures

Stresses for the elastic-plastic transition and fully plastic state have been derived for a thin rotating disc with rigid shaft at different temperatures and results have been discussed and depicted graphically. It has been observed that at room temperature rotating disc made of compressible material and of smaller radii ratio yields at the internal surface at a higher angular speed as compared to rotating disc made of incompressible material. With the introduction of thermal effect rotating disc yields at the outer surface at a lesser angular speed as compared to rotating disc at room temperature. The circumferential stress is maximum at the outer surface of the rotating disc with further increases with the increase in temperature. It means that angular speed of the rotating disc is less than that of the temperature-loaded disc in the fully plastic case.

Creep deformation and stress analysis in a transversely material disk subjected to rigid shaft

2019 ◽  
Vol 25 (1) ◽  
pp. 17-25
Author(s):  
Pankaj Thakur ◽  
Monika Sethi
Keyword(s):  
Stress Analysis ◽  
Creep Deformation ◽  
Radial Stress ◽  
Hoop Stress ◽  
Rotating Disk ◽  
Angular Speed ◽  
Transition Theory ◽  
Strain Rates ◽  
Maximum Value ◽  
Inner Surface

The purpose of this paper is to present a study of creep deformation and stress analysis in a transversely material disk subjected to the rigid shaft by using Seth’s transition theory. It has been observed that radial stress has the maximum value at the inner surface of the rotating disk made of isotropic material as compared to the hoop stress and this value of radial stress further increases with the increase in the value of angular speed. Strain rates have maximum values at the inner surface for the disk made of transversely material.

scholarly journals Steady thermal stress and strain rates in a rotating circular cylinder under steady state temperature

2014 ◽  
Vol 18 (suppl.1) ◽  
pp. 93-106
Author(s):  
Thakur Pankaj
Keyword(s):  
Thermal Stress ◽  
Steady State ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Stress And Strain ◽  
Strain Rates ◽  
Rotating Circular Cylinder ◽  
Steady State Temperature ◽  
Incompressible Materials ◽  
Thermal Stress And Strain

Thermal stress and strain rates in a thick walled rotating cylinder under steady state temperature has been derived by using Seth?s transition theory. For elastic-plastic stage, it is seen that with the increase of temperature, the cylinder having smaller radii ratios requires lesser angular velocity to become fully plastic as compared to cylinder having higher radii ratios The circumferential stress becomes larger and larger with the increase in temperature. With increase in thickness ratio stresses must be decrease. For the creep stage, it is seen that circumferential stresses for incompressible materials maximum at the internal surface as compared to compressible material, which increase with the increase in temperature and measure n.

scholarly journals Steady thermal stress and strain rates in a circular cylinder with non-homogeneous compressibility subjected to thermal load

2014 ◽  
Vol 18 (suppl.1) ◽  
pp. 81-92 ◽  
Author(s):  
Thakur Pankaj
Keyword(s):  
External Surface ◽  
Circumferential Stress ◽  
Internal Surface ◽  
Incompressible Material ◽  
Pressure Effects ◽  
Homogeneous Material ◽  
Strain Rates ◽  
Compressible Material ◽  
Homogeneous Case ◽  
Effects Of Temperature

The non-homogeneity is assumed due to variation of modulus of compression. It has seen that in the presence of temperature, a cylinder made of non-homogeneous material k<0 (Non-homogeneity is less at internal surface than at outer surface) require high pressure to become fully plastic as is required for initial yielding and this pressure goes on increasing with the increases in temperature, showing that a cylinder made of non-homogeneous material k<0 is on the safer side of design. For homogeneous case, it has been observed that the circumferential stress has maximum value at the external surface of the cylinder made of incompressible material as compared to compressible material. For Homogeneous case, with effects of temperature reduces the stresses at the external surface of the cylinder in comparison to pressure effects only. Strain rates are found to be maximum at the internal surface of the cylinder made of compressible material and they decrease with the radius. With the introduction of temperature effect, the creep rates have higher values at the internal surface but lesser values at the external surface as compare to a cylinder subjected to pressure only.

Influence of anisotropy on creep in functionally graded variable thickness rotating disc

2021 ◽  
pp. 030932472199997
Author(s):  
Kishore Khanna ◽  
Vinay Kumar Gupta ◽  
Neeraj Grover
Keyword(s):  
Axial Direction ◽  
Functionally Graded ◽  
Strain Rates ◽  
Lower Yield ◽  
Rotating Disc ◽  
Creep Response ◽  
Varying Thickness ◽  
Disc Material ◽  
Lower Yield Strength ◽  
Tangential Directions

The study is carried out to develop a mathematical model to analyze creep response of a varying thickness rotating disc made of anisotropic functionally graded 6061Al-SiCw.composite. The thickness and content of reinforcement (SiCw) in the disc are assumed to decrease radially according to power law. The yielding of disc material is according to Hill’s criterion and creeping as per threshold stress based law. The developed model is used to obtain the creep stresses and strain rates in the disc for various types of materials’ anisotropy. The stresses and strain rates are noticed to depend on the materials’ anisotropy. The study reveals that the presence of kind of anisotropy wherein the disc material exhibits lower yield strength toward the radial and tangential directions than the axial direction is beneficial in reducing the creep stresses and creep rates in the disc, in comparison to isotropic FGM disc. An anisotropic FG disc, which has highest and the lowest yield strengths, respectively, along the axial and radial directions shows superior creep response.

scholarly journals Elastic-plastic transition stresses in a transversely isotropic thick-walled cylinder subjected to internal pressure and steady-state temperature

2009 ◽  
Vol 13 (4) ◽  
pp. 107-118 ◽  
Author(s):  
Thakur Pankaj
Keyword(s):  
Steady State ◽  
Internal Pressure ◽  
Isotropic Material ◽  
Internal Surface ◽  
Transversely Isotropic ◽  
Percentage Increase ◽  
Transversely Isotropic Material ◽  
Elastic Plastic ◽  
Steady State Temperature ◽  
Walled Cylinder

Elastic-plastic transitional stresses in a transversely isotropic thick-walled cylinder subjected to internal pressure and steady-state temperature have been derived by using Seth's transition theory. The combined effects of pressure and temperature has been presented graphically and discussed. It has been observed that at room temperature, thick-walled cylinder made of isotropic material yields at a high pressure at the internal surface as compared to cylinder made of transversely isotropic material. With the introduction of thermal effects isotropic/transversely isotropic cylinder yields at a lower pressure whereas cylinder made of isotropic material requires less percentage increase in pressure to become fully-plastic from its initial yielding as compared to cylinder made of transversely isotropic material.

scholarly journals Measured and Computed Temperature Distributions in the Law Dome Ice Cap, Antarctica

1976 ◽  
Vol 16 (74) ◽  
pp. 99-110 ◽  
Author(s):  
W.F. Budd ◽  
N.W. Young ◽  
C.R. Austin
Keyword(s):  
Temperature Distribution ◽  
Negative Temperature ◽  
Strain Rates ◽  
Accumulation Rates ◽  
High Accumulation ◽  
Ice Cap ◽  
Steady State Temperature ◽  
Surface Measurements ◽  
Depth Gradients ◽  
Temperature Depth

AbstractBy 1969 considerable data had been collected over Law Dome from surface measurements. These included surface elevation, ice thickness, accumulation rates, ice movement and strain-rates, surface mean temperatures, and several temperature-depth gradients. Since then core drilling up to 380 m in depth has been carried out from the summit to the coast where the cores reached close to the bed. The bore holes have been concentrated on two main flow lines: one to Cape Folger and the other to Cape Poinsett. The bore-hole temperatures give a clear indication of the temperature distribution throughout the ice cap.Numerical modelling shows that the measured deep temperatures closely match the steady-state temperature distribution calculated from the present regime. The variations in the temperature profiles over the dome are primarily associated with the flow regime.The Cape Folger line has low accumulation rates and low velocities which results in positive surface temperature-depth gradients increasing towards the coast. By contrast the Cape Poinsett line has high accumulation rates and high velocities which result in a large negative temperature-depth gradient there. The profile at the Dome summit is close to isothermal primarily due to the high accumulation rates and lack of horizontal motion.

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