Application of Crack Arrest Theory to a Thermal Shock Experiment

2009 ◽  
pp. 392-392-30 ◽  
Author(s):  
RD Cheverton ◽  
PC Gehlen ◽  
GT Hahn ◽  
SK Iskander
Keyword(s):  
Thermal Shock ◽  
Crack Arrest ◽  
Shock Experiment

KIa Crack Arrest Toughness Assessment Using Thermal Shock on Notched Disks

2004 ◽  
Author(s):  
Me´jido Hajjaj ◽  
Ste´phane Bugat ◽  
Clotilde Berdin ◽  
Philippe Bompard
Keyword(s):  
Crack Propagation ◽  
Thermal Shock ◽  
Static Analysis ◽  
Thermal Analyses ◽  
Crack Arrest ◽  
The Finite Element Method ◽  
Wave Interference ◽  
Shock Experiment ◽  
T Values ◽  
Arrest Toughness

The aim of the study is to validate the KIa-T curve on a thermal shock experiment performed on a notched disk (DTSE) taken from a A533-B type steel. Several experiments have been performed. Non linear thermal analyses were carried out using the finite element method in order to obtain the full thermal field within the specimen during crack propagation. The results obtained are in excellent agreement with the experimental results. The DTSE is also interpretated in static terms to compare the obtained KIa (T) values with the limit curve. Finally, dynamic F.E. simulations allow to estimate the influence of dynamic effects in the DTSE and thus validate the methodology. According to the computations, the crack arrested when dK/da>0 and dKd/da = 0. The comparison between stress intensity factor computed from elastic-static analysis (or dynamic) and RCC-M code demonstrated the conservatism of the approach. Then static analysis is sufficient to analyse the result, since no wave interference with the crack propagation was identified.

3D Modeling of Crack Arrest Experiment With a Local Approach

2009 ◽  
Author(s):  
Anna Dahl ◽  
Dominique Moinereau ◽  
Clotilde Berdin ◽  
Yves Meziere
Keyword(s):  
Thermal Shock ◽  
3D Modeling ◽  
Critical Stress ◽  
Local Stress ◽  
Crack Arrest ◽  
Cleavage Crack ◽  
Local Approach ◽  
Stress Criterion ◽  
Shock Experiment ◽  
Front Shape

A local stress criterion based on the maximal principal stress is applied for 3D-modeling crack arrest experiments: thermal shock experiments on precracked disc. The crack front shape is simulated and compared to the experimental results. A scatter in critical stress for cleavage crack arrest is introduced through Monte-Carlo simulations with the Weibull distribution. As a result, for the thermal shock experiment on precracked disc, the scatter in critical stress has no influence on the crack length at arrest, but the regularity of the simulated crack arrest front depends on it. This result can be due to the mechanical aspect of the test rather than to the micro-mechanisms of cleavage crack arrest: the vibration of the disc induces the crack closure.

The Limitation of Evaluating Thermal Shock Resistance of Al2O3-SiO2 Refractory by Measuring Strength Loss Rate

2011 ◽  
Vol 295-297 ◽  
pp. 2309-2313
Author(s):  
Xin Liu ◽  
Dian Li Qu ◽  
Zhi Jian Li
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Loss Rate ◽  
Strength Loss ◽  
X Ray Diffraction ◽  
Initial State ◽  
X Ray ◽  
Cold Crushing Strength ◽  
Shock Experiment ◽  
Shock Resistance

This paper deeply studied the limitation of evaluating the thermal shock resistance of Al2O3-SiO2 refractory by measuring Strength Loss Rate (SLR). By means of supersonic, X-ray diffraction (XRD), the results were drawn as followed.1)After the thermal shock experiment for mullite based A-S refractory, which were composed by mullite and corundum, the supersonic velocity slowed down as it going through the sample while the cold crushing strength abnormally increased at initial state.2) The strength increased remarkably with the ascending of mullite fraction.3)It is inadequate to evaluate the thermal shock resistance of mullite based A-S refractory by strength loss rate.

Crack Arrest in Brittle Ceramics Subjected to Thermal Shock and Ablation

2014 ◽  
Vol 31 (9) ◽  
pp. 094601 ◽  
Author(s):  
Yan-Wei Wang ◽  
He-Long Yu ◽  
Hong-Xiang Tang ◽  
Xue Feng
Keyword(s):  
Thermal Shock ◽  
Crack Arrest

The heavy-section steel technology pressurized-thermal-shock experiment, PTSE-1

1986 ◽  
Vol 23 (1) ◽  
pp. 81-97 ◽  
Author(s):  
R.H. Bryan ◽  
B.R. Bass ◽  
J.G. Merkle ◽  
C.E. Pugh ◽  
G.C. Robinson ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Heavy Section ◽  
Steel Technology ◽  
Pressurized Thermal Shock ◽  
Shock Experiment

Thermal Shock Experiment and Simulation of Ceramic/Metal Gradient Thermal Barrier Coating

2007 ◽  
Vol 336-338 ◽  
pp. 1818-1822
Author(s):  
Jin Sheng Xiao ◽  
Kun Liu ◽  
Wen Hua Zhao ◽  
Wei Biao Fu
Keyword(s):  
Heat Transfer ◽  
Thermal Shock ◽  
Thermal Barrier Coating ◽  
Thermal Stresses ◽  
Initial Temperature ◽  
Thermal Barrier ◽  
Water Spray ◽  
Barrier Coating ◽  
Shock Experiment ◽  
Two Stages

A thermal shock experiment is designed to explore the thermal shock properties of ceramic/metal gradient thermal barrier coating. The specimens are heated up by oxygen-acetylene flame and cooled by water spray. The experiment procedure includes two stages, heating the specimen from the initial temperature 30°C for 40s, and then cooling for 20s. The heat transfer and the associated thermal stresses produced during the thermal shock procedure are simulated by finite element method. Experimental results indicated that the specimen of gradient coating behaves better in thermal shock experiments, which agree with the results of simulation.

Remaining life of a vessel containing an internal corner crack under repeated thermal shock

1997 ◽  
Vol 211 (3) ◽  
pp. 215-219 ◽  
Author(s):  
H W Ng ◽  
C K Lee
Keyword(s):  
Thermal Shock ◽  
Crack Growth ◽  
Finite Element Modelling ◽  
Slow Growth ◽  
Crack Arrest ◽  
Assessment Procedure ◽  
Remaining Life ◽  
Corner Crack ◽  
Defect Assessment ◽  
Accelerate Crack Growth

The remaining life for a hypothetical pressure vessel containing a defect which is subject to thermal shock has been calculated. Twelve cases of thermal shock loads of different severity characterized by the dimensionless parameters, Biot (B) and Fourier (F) numbers, were analysed by finite element modelling (FEM). The estimation of remaining life for each case was carried out based on the PD6493 defect assessment procedure (1). The effect of thermal shock on the crack growth rate was quantified showing that more severe shocks accelerate crack growth while less severe shocks may lead to slow growth or eventual crack arrest.

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