Creep Analysis of a Variable Thickness Rotating FGM Disc using Tresca Criterion

2015 ◽  
Vol 65 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Kishore Khanna ◽  
V. K. Gupta ◽  
S. P. Nigam
Keyword(s):  
Variable Thickness ◽  
Creep Analysis ◽  
Tresca Criterion

scholarly journals Creep Response of Rotating Composite Discs having Exponential Hyperbolic Linear and Constant Thickness Profiles

2020 ◽  
Vol 70 (3) ◽  
pp. 292-298
Author(s):  
Rajinder Singh ◽  
Ravindra K. Saxena ◽  
Kishore Khanna ◽  
V. K. Gupta
Keyword(s):  
Variable Thickness ◽  
Creep Behaviour ◽  
Steady State Creep ◽  
Constant Thickness ◽  
Strain Rates ◽  
Creep Response ◽  
Thickness Profile ◽  
Disc Material ◽  
Tresca Criterion ◽  
Different Thickness

The study compares the steady state creep response of rotating Al-SiC discs having constant, linear, hyperbolic and exponential thickness with different thickness profiles. All the discs are assumed to have equal volume with the same average thickness. The creep behaviour of the disc material is described by threshold stress based law while the yielding is assumed to follow Tresca criterion. The variable thickness disc is observed to have superior creep response, expressed in terms of stresses and strain rates, to a constant thickness disc. Amongst variable thickness discs, the creep response is observed to be superior for linear thickness disc, when the inner thickness of all the discs is kept the same. However, for the same outer thickness, the disc having hyperbolic thickness profile exhibits the best creep response.

Thermomechanical Creep Analysis of FGM Thick Cylindrical Pressure Vessels with Variable Thickness

2018 ◽  
Vol 10 (01) ◽  
pp. 1850008 ◽  
Author(s):  
Mosayeb Davoudi Kashkoli ◽  
Khosro Naderan Tahan ◽  
Mohammad Zamani Nejad
Keyword(s):  
Temperature Gradient ◽  
Differential Equations ◽  
Variable Thickness ◽  
Pressure Vessel ◽  
Shear Deformation Theory ◽  
Pressure Vessels ◽  
Mechanical And Thermal Properties ◽  
Creep Response ◽  
Cylindrical Pressure Vessel ◽  
Creep Analysis

In the present study, a theoretical solution for thermomechanical creep analysis of functionally graded (FG) thick cylindrical pressure vessel with variable thickness based on the first-order shear deformation theory (FSDT) and multilayer method (MLM) is presented. To the best of the researchers’ knowledge, in the literature, there is no study carried out into FSDT and MLM for creep response of cylindrical pressure vessels with variable thickness under thermal and mechanical loadings. The vessel is subjected to a temperature gradient and nonuniform internal pressure. All mechanical and thermal properties except Poisson’s ratio are assumed to vary along the thickness direction based on a power-law function. The thermomechanical creep response of the material is described by Norton’s law. The virtual work principle is applied to extract the nonhomogeneous differential equations system with variable coefficients. Using the MLM, this differential equations system is converted into a system of differential equations with constant coefficients. These set of differential equations are solved analytically by applying boundary and continuity conditions between the layers. In order to verify the results of this study, the finite element method (FEM) has been used and according to the results, good agreement has been achieved. It can be concluded that the temperature gradient has significant influence on the creep responses of FG thick cylindrical pressure vessel.

Analysis of Creep in Rotating Disks Based on the Tresca Criterion and Associated Flow Rule

1956 ◽  
Vol 23 (2) ◽  
pp. 231-238
Author(s):  
A. M. Wahl
Keyword(s):  
Steady State ◽  
Creep Rate ◽  
Constant Temperature ◽  
Variable Thickness ◽  
Constant Thickness ◽  
Flow Rule ◽  
Test Results ◽  
Rotating Disks ◽  
Tresca Criterion ◽  
Associated Flow Rule

Abstract An analysis of creep deformations in rotating disks based on the Tresca criterion and the associated flow rule is presented. Assuming steady-state creep conditions and a creep rate equal to a function of stress times a function of time, the method is applied to the following cases: (a) Disk with constant thickness and constant temperature, (b) disk with variable thickness and constant temperature, and (c) disk with variable thickness and variable temperature. In many cases, the equations can be expressed in closed form. Comparison is made with test results on rotating disks at elevated temperature as reported in a previous paper. Based on certain stress-creep-rate relations, the method is also applied to the problem of calculating the transient change in stress when the stress distribution changes from an initial to a steady-state condition during the starting period. It is suggested that the simplification effected by the use of these methods may be of value for design purposes pending the development of more accurate methods based on test results.

Thermo-Elastic Creep Analysis and Life Assessment of Thick Truncated Conical Shells with Variable Thickness

2019 ◽  
Vol 11 (09) ◽  
pp. 1950086
Author(s):  
Tahereh Taghizadeh ◽  
Mohammad Zamani Nejad ◽  
Mosayeb Davoudi Kashkoli
Keyword(s):  
Variable Thickness ◽  
Shear Deformation Theory ◽  
Accurate Solution ◽  
Life Assessment ◽  
Computationally Efficient ◽  
Equilibrium Equations ◽  
Energy Principle ◽  
Conical Shells ◽  
Total Potential ◽  
Creep Analysis

A semi-analytical method is presented to investigate time-dependent thermo-elastic creep behavior and life assessment of thick truncated conical shells with variable thickness subjected to internal pressure and thermal load. Based on the first-order shear deformation theory (FSDT), equilibrium equations and boundary conditions are derived using the minimum total potential energy principle. To the best of the researcher’s knowledge, in previous studies, thermo-elastic creep analysis of conical shell with variable thickness based on the FSDT has not been investigated. Norton’s law is assumed as the material creep constitutive model. The multilayered method is proposed to solve the resulting equations, which yields an accurate solution. Subsequently, the stresses at different creep times can be obtained by means of an iterative approach. Using Robinson’s linear life fraction damage rule, the creep damages of conical shells are determined and Larson–Miller parameter (LMP) is employed for assessing the remaining life. The results of the proposed approach are validated with those of the finite element method (FEM) and good agreement was found. The results indicate that the present analysis is accurate and computationally efficient.

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