Estimation of the V-Factor for Circumferentially Cracked Pipes Under Combined Thermal and Mechanical Stresses Using a Strain-Based Failure Assessment Diagram

This paper presents finite element solutions for elastic-plastic J for circumferentially cracked pipes under combined mechanical and thermal loads in terms of the V/Vo factor used within a strain-based failure assessment diagram. In this study, 3-dimensional finite element analyses are conducted to calculate the V-factor under combined mechanical and thermal load. It is found that estimation of V/Vo is sensitive to the method used for its evaluation. For larger thermal stresses, currently proposed estimation methods are overly conservative.

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An Estimation of C(t) of Transient Creep Under Combined Mechanical and Thermal Stresses

ASME 2010 Pressure Vessels and Piping Conference: Volume 5 ◽

10.1115/pvp2010-25372 ◽

2010 ◽

Author(s):

Chang-Young Oh ◽

Tae-Kwang Song ◽

Yun-Jae Kim

Keyword(s):

Finite Element ◽

High Temperature ◽

Thermal Load ◽

Thermal Stresses ◽

Mechanical Load ◽

Creep Condition ◽

Transient Creep ◽

Finite Element Analyses ◽

3 Dimensional ◽

Dimensional Finite Element

In this paper, a prediction of C(t), a crack tip parameter for the transient creep condition, for the circumferential cracked pipe under combined mechanical and thermal stresses are presented. The estimation formulae for C(t)-integral of the cracked component operating under mechanical load alone have been provided for decades [1–6]. However, high temperature structures usually work under combined mechanical and thermal load. And the interactions between mechanical and thermal loads make the relaxation rate different from those produced under mechanical load alone. In this study, 3-dimensional finite element analyses are conducted to calculate the C(t)-integral under combined mechanical and thermal load. As a result, redistribution time for the crack under combined mechanical and thermal load is re-defined to quantify the C(t)-integral. The estimation of C(t)-integral using this proposed redistribution time agrees well with FE results.

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Finite Element Analysis of Thermal Stresses in Circumferential Cast Clasps of Removable Partial Dentures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.23.229 ◽

2007 ◽

Vol 23 ◽

pp. 229-232

Author(s):

Liliana Sandu ◽

Nicolae Faur ◽

Cristina Bortun ◽

Sorin Porojan

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Thermal Stresses ◽

Element Analysis ◽

3 Dimensional ◽

Thermal Changes ◽

The Finite Element Analysis ◽

Dimensional Finite Element ◽

Back Action ◽

Aggressive Effect

Several studies evaluated the removable partial dentures by the finite element analysis, but none of them evaluated thermal stresses. The purpose of the study was to explore the influence of thermal oral changes induced by hot/cold liquids and food on the circumferential cast clasps of removable partial dentures. A 3-dimensional finite element method was used to explore the temperature distribution, thermal stress and the influence of thermal changes on stresses and displacements of circumferential clasps during functions. Thermal variations induce stresses in dental clasps, high temperatures having a more aggressive effect than lower one. Cold liquids and food induce high stresses in the retentive clasp arms while hot ones in the occlusal rests of the clasps and for the back action clasp also in the minor connector. The study suggests the importance of consFigureidering thermal variations for stress analyses of the cast clasps.

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Computed Tomography–Based 3-Dimensional Finite Element Analyses of Various Types of Plates Placed for a Virtually Reduced Unilateral Condylar Fracture of the Mandible of a Patient

Journal of Oral and Maxillofacial Surgery ◽

10.1016/j.joms.2017.02.014 ◽

2017 ◽

Vol 75 (6) ◽

pp. 1239.e1-1239.e11 ◽

Cited By ~ 9

Author(s):

Kazuhiro Murakami ◽

Kazuhiko Yamamoto ◽

Tsutomu Sugiura ◽

Satoshi Horita ◽

Yumiko Matsusue ◽

...

Keyword(s):

Computed Tomography ◽

Finite Element ◽

Finite Element Analyses ◽

Condylar Fracture ◽

3 Dimensional ◽

Dimensional Finite Element

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Estimation of V Factor Under Combined Thermal and Mechanical Stress for Circumferential Cracked Pipes

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2009-77355 ◽

2009 ◽

Author(s):

Tae-Kwang Song ◽

Yun-Jae Kim ◽

Chang-Kyun Oh ◽

Kamran Nikbin ◽

Robert A. Ainsworth

Keyword(s):

Finite Element ◽

Thermal Stress ◽

Plastic Strain ◽

Strain Hardening ◽

Mechanical Loading ◽

Thermal Load ◽

Finite Element Analyses ◽

Loading Mode ◽

Failure Assessment ◽

Factor Estimation

This paper provides V-factor estimation under combined mechanical and thermal load for circumferential cracked pipes. In this study, the effects of types and magnitudes of the thermal stress, mechanical loading mode, crack geometry, and plastic strain hardening on variations of V-factor are estimated. The results of finite element analyses are compared with R6 values. As a result, it is shown that R6 gives generally conservative results. The conservatism is especially increased for the combination of large mechanical and thermal load. As a result, new estimation equation which uses failure assessment curve in R6 is proposed for V-factor and gives less conservative results.

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