Thermoelectroelastic Responses in Orthotropic Piezoelectric Hollow Cylinders Subjected to Thermal Shock and Electric Excitation

2005 ◽  
Vol 24 (10) ◽  
pp. 1085-1103 ◽  
Author(s):  
H. L. Dai ◽  
X. Wang ◽  
Q. H. Dai
Keyword(s):  
Thermal Shock ◽  
Electric Excitation ◽  
Hollow Cylinders

Crack Propagation Calculation for Axial Cracks in Hollow Cylinders Subjected to Thermal Shock

2021 ◽  
Author(s):  
Diego F. Mora M. ◽  
Markus Niffenegger
Keyword(s):  
Fracture Toughness ◽  
Finite Element ◽  
Crack Propagation ◽  
Weight Function ◽  
Thermal Shock ◽  
Initial Crack ◽  
Fe Model ◽  
Simple Method ◽  
Hollow Cylinders ◽  
Fracture Arrest

Abstract The core region of the RPV can be considered a hollow circular cylinder disregarding the geometrical details due to nozzles. This contribution investigates the prediction capabilities for crack initiation, crack growth and arrest by means of a rather simple method based on the closed-weight function formula for the stress intensity factor (SIF) for axial cracks in hollow cylinders subjected to thermal shock. The method is explained together with some illustrative examples for real low allow steel used in nuclear applications. In order to obtain the temperature and stress distribution in the cylinder during the thermal shock, a finite element (FE) model is defined to obtain the uncoupled solution of these two fields needed for the closed-weight function. Since the material exhibits a ductile-brittle transition fracture behavior, the temperature-dependent fracture toughness for initiation and for arrest are described using the ASME model. The solution for the SIF is based on linear elastic fracture mechanics (LEFM) and therefore only elastic material is assumed and the crack can propagate in brittle manner. The crack initiates propagation if the SIF value at the crack tip reaches the fracture toughness (for initiation) and propagates unstably in mode I unless the fracture arrest toughness is reached. The quality of the solution is checked by comparing the obtained solution for a “stationary” crack with the calculated extended finite element method (XFEM) solution for the same loading transient. The results show that for some geometries of the cylinder, the crack stops and in some other cases the crack propagates until the cylinder fails. The combined closed-weight function-initiation-growth-arrest (WFF-IGA) algorithm does not require expensive computational resources and gives fast reliable results. The WFF-IGA method provides a powerful and economical way to predict the crack propagation and arrest of the initial crack. This is an advantage when an optimization of the structure is needed.

A Method of Analysis to Estimate Thermal Down-Shock Stress Profiles in Hollow Cylinders when Subjected to Transient Heat/Cooling Cycle

2012 ◽  
Vol 445 ◽  
pp. 893-898
Author(s):  
M.A. Ali ◽  
S.T. Hasan ◽  
D.P. Myriounis
Keyword(s):  
Cylindrical Shell ◽  
Thermal Shock ◽  
Thermal Gradient ◽  
Shock Loading ◽  
Linear Equations ◽  
Time Period ◽  
Hollow Cylinders ◽  
Stress Profiles ◽  
Forced Air ◽  
Shock Stress

An empirical solution for the thermal shock stresses in cylindrical shell presented when cylinder is subjected to heating or re-heating case and down-shock cooling by forced air case. Linear equations are developed to describe the severity of thermal shock loading. When thermal gradient and time period are in consideration, it is shown the equations displays good approximation for major characteristics of the thermal shock stress profiles.

Generalized Thermoelasticity Theories for Axisymmetric Hollow Cylinders Under Thermal Shock with Variable Thermal Conductivity

2018 ◽  
Vol 06 (03n04) ◽  
pp. 1850006
Author(s):  
Ashraf M. Zenkour
Keyword(s):  
Thermal Conductivity ◽  
Thermal Shock ◽  
Generalized Thermoelasticity ◽  
Present Theory ◽  
Variable Thermal Conductivity ◽  
Coupled Thermoelasticity ◽  
Heating Source ◽  
Special Cases ◽  
Hollow Cylinders ◽  
Time Parameters

The thermoelastic problem of clamped axisymmetric infinite hollow cylinders under thermal shock with variable thermal conductivity is presented. The outer surface of infinite hollow cylinder is considered to be thermally insulated while inner surface is subjected to an initial heating source. In addition, the cylinder is considered to be clamped at its inner and outer radii. Generalized thermoelasticity theories are used to deal with the field quantities. All generalized thermoelasticity theories such as Green and Lindsay, Lord and Shulman, and coupled thermoelasticity (CTE) are considered as special cases of the present theory. Effects of variable thermal conductivity and time parameters on radial displacement, temperature, and stresses of the hollow cylinders are investigated.

scholarly journals Analysis of Axial Cracks in Hollow Cylinders Subjected to Thermal Shock by Using the Thermal Weight Function Method

1996 ◽  
Vol 118 (2) ◽  
pp. 146-153 ◽  
Author(s):  
C.-C. Ma ◽  
M.-H. Liao
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Weight Function ◽  
Thermal Shock ◽  
Function Method ◽  
Thermal Loading ◽  
Weight Functions ◽  
Weight Function Method ◽  
Hollow Cylinders

In this study, stress intensity factors for axial cracks in hollow cylinders subjected to thermal shock are determined by using the thermal weight function method. The thermal weight function is a universal function for a given cracked body and can be obtained from any arbitrary mechanical loading system. The thermal weight function may be thought of as Green’s function for the stress intensity factor of cracked bodies subject to thermal loadings. Once the thermal weight function for a cracked body is determined, the stress intensity factor for any arbitrary distributed thermal loading can be simply and efficiently evaluated through the integration of the product of the temperature and the correspondent thermal weight function. A numerical boundary element method for the determination of thermal weight functions for axial cracks in hollow cylinders is used in this study to evaluate the transient stress intensity factor. As a demonstration, some examples of axial cracks in hollow cylinders subjected to thermal shock are solved by using the thermal weight function method, and the results are compared with available results in the published literature.

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