Modeling Creep Analysis of Thermally Graded Anisotropic Rotating Composite Disc

2018 ◽  
Vol 10 (06) ◽  
pp. 1850063 ◽  
Author(s):  
Tania Bose ◽  
Minto Rattan
Keyword(s):  
Temperature Field ◽  
Elevated Temperatures ◽  
Yield Criterion ◽  
Particulate Composite ◽  
Rotating Disc ◽  
Modeling And Analysis ◽  
Creep Analysis ◽  
Modeling Creep ◽  
Hill's Yield Criterion ◽  
Silicon Carbide Particulate

Mathematical modeling for steady-state creep has been done for an anisotropic disc of aluminium-silicon carbide particulate composite rotating at elevated temperatures under a thermal gradient. Creep modeling and analysis has been done using Hill’s yield criterion for a disc operating under a parabolic distributed temperature and its comparison is made with the disc operating under uniform temperature throughout the radius. The results are expressed graphically in designer friendly manner for the stress and strain rate distributions under a graded temperature field. It can be seen that the parabolic temperature field has a significant effect on the creep behavior of the anisotropic disc. Thus, the temperature gradient effect should be considered while designing the anisotropic rotating disc.

Creep Analysis in Anisotropic Composite Rotating Disc with Hyperbolically Varying Thickness

2011 ◽  
Vol 110-116 ◽  
pp. 4171-4177
Author(s):  
Vandana Gupta ◽  
S.B. Singh
Keyword(s):  
Creep Behavior ◽  
Yield Criterion ◽  
Radial Strain ◽  
Outer Radius ◽  
Rotating Disc ◽  
Tangential Strain ◽  
Varying Thickness ◽  
Creep Analysis ◽  
Inner Radius ◽  
Hill's Yield Criterion

Steady state creep in a anisotropic rotating disc made of Al-SiCp composite having hyperbolically varying thickness has been investigated using Hill’s yield criterion. The creep behavior is supposed to follow the Sherby’s law in present study. The stress and strain distributions are calculated for different combinations of anisotropic constants. The change in the radial stress is not significant while the tangential stress is changed with the change in the material constants. The tangential strain rates are highest at the inner radius of the disc and then decreases towards the outer radius of the disc. The radial strain rate which is compressive in nature becomes tensile in middle of the disc for some specific values of anisotropic constants. The study reveals that the anisotropy has a significant effect on the creep behavior of rotating disc. Thus for the safe design of the rotating disc the effect of anisotropy should be taken care of.

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.

Steady State Creep of Isotropic Rotating Composite Disc Under Thermal Gradation

2017 ◽  
Vol 09 (06) ◽  
pp. 1750077 ◽  
Author(s):  
Tania Bose ◽  
Minto Rattan ◽  
Neeraj Chamoli
Keyword(s):  
Steady State ◽  
Thermal Gradient ◽  
Elevated Temperatures ◽  
Yield Criterion ◽  
Aluminum Matrix ◽  
Radial Distance ◽  
Outer Radius ◽  
Steady State Creep ◽  
Uniform Temperature ◽  
Silicon Carbide Particulate

An attempt has been made to investigate steady state creep behavior of thermally graded isotropic discs rotating at elevated temperatures. For this purpose, composite discs of aluminum matrix reinforced with silicon carbide particulate have been taken. Modeling of stress and strain rate distributions for discs operating under linear thermal gradient has been done using von Mises’ yield criterion and threshold stress-based creep law. Similarly modeling has been done for discs operating under non-linear thermal gradient. The results are compared with the disc having a uniform temperature profile from inner to outer radius and are displayed graphically in designer friendly format for the said temperature profiles. A small variation is observed for radial and tangential stresses for the said thermal gradations. However, the strain rates vary significantly in the presence of thermal gradations as compared to a disc having uniform temperature throughout the radial distance. Thus, it is observed that there is a need to extend the domain of thermal gradation for designing rotating discs.

scholarly journals Elasto - plastic analysis of anisotropic hardening materials by finite element method

1985 ◽  
Vol 7 (1) ◽  
pp. 8-13
Author(s):  
Tran Duong Hien
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Program ◽  
Yield Criterion ◽  
Element Model ◽  
Isotropic Hardening ◽  
Anisotropic Hardening ◽  
Numerical Examples ◽  
Plastic Analysis ◽  
Hill's Yield Criterion

An elasto- plastic analysis for general three dimes10nal problems using a finite element model is presented. The analysis is based on Hill's yield criterion which included anisotropic materials displaying kinematic - isotropic hardening. The validity and practical applicability of the algorithm are illustrated by a number of numerical examples, calculated by a computer program written in fortran.

Design Sensitivity Analysis and Optimization of Nonlinear Anisotropic Structures

2004 ◽  
Vol 261-263 ◽  
pp. 809-814
Author(s):  
Tae Hee Lee ◽  
J.J. Jung
Keyword(s):  
Sensitivity Analysis ◽  
Nonlinear Analysis ◽  
Yield Criterion ◽  
Design Sensitivity ◽  
Euler Method ◽  
Design Sensitivity Analysis ◽  
Design Variables ◽  
Nonlinear Constitutive Equation ◽  
Anisotropic Structures ◽  
Hill's Yield Criterion

Nonlinear analysis of anisotropic structures is described by using Hill's yield criterion that anisotropic yield contour is assumed to be retained its shape during the hardening process. Nonlinear constitutive equation of anisotropic material is derived using plastic potential concept. Linear strain hardening model is utilized and forward Euler method is employed as a stress integration method. Newton-Raphson method is implemented for numerical nonlinear analysis. Direct differentiation method differentiating directly the equilibrium equation with respect to design variables is applied to design sensitivity analysis of nonlinear anisotropic plate. The results of design sensitivity analysis are compared with those of finite difference method to verify the accuracy. Optimization is accomplished for a rectangular plate using evaluated sensitivity coefficients.

Creep behaviour of components containing cracks—a critical review

1978 ◽  
Vol 13 (1) ◽  
pp. 35-51 ◽  
Author(s):  
E G Ellison ◽  
M P Harper
Keyword(s):  
Crack Propagation ◽  
Critical Review ◽  
Elevated Temperatures ◽  
Creep Behaviour ◽  
Crack Tip ◽  
Ductile Materials ◽  
Analysis Techniques ◽  
Reference Stress ◽  
Creep Analysis ◽  
Available Information

The prediction of crack propagation rates at elevated temperatures is important and this paper provides a critical review of available information and models for behaviour. For simplicity, behaviour is divided into three situations. At one extreme, a brittle situation may exist in which the material is brittle and the degree of constraint high, so that substantially plane strain conditions exist and stress redistribution at the crack tip is small; in this situation, the fracture is a local crack tip event and the stress intensity may be of use in correlaiting creep crack propagation data. At the other extreme, ductile behaviour may result if the material is ductile and the constraint is low with plane stress conditions prevailing; in this case, stresses at and near the crack tip will redistribute quickly down to more even values and conventional creep analysis techniques using, say, the reference stress will be most useful, particularly for estimating times to rupture. It is postulated that there is also a large intermediate régime, termed quasi-brittle, in which ductile materials under high constraint exhibit brittle characteristics. A new parameter, C∗, appears to be of more general use in this case and even be extended to other situations. Finally, an attempt is made to survey the information available on the effects of environment on crack propagation at high temperature, though conclusions are necessarily tentative at this time.

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