Finite-Element Analysis of Waspaloy Using Sinh Creep-Damage Constitutive Model Under Triaxial Stress State

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Mohammad Shafinul Haque ◽  
Calvin Maurice Stewart
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Creep Deformation ◽  
Damage Evolution ◽  
Rupture Life ◽  
Creep Damage ◽  
Nickel Base Superalloy ◽  
Element Analysis ◽  
Stress Levels ◽  
Nickel Base

The creep deformation and damage evolution of nickel base superalloy (Waspaloy) at 700 °C are studied using the classic Kachanov–Rabotnov (KR) and a recently developed Sin-hyperbolic (Sinh) model. Uniaxial creep deformation and Bridgman rupture data collected from literature are used to determine the model constants and to compare the KR and the Sinh solutions. Finite-element (FE) simulations on a single eight-node element are conducted to validate the accuracy of the FE code. It is observed that KR cannot predict the creep deformation, damage, and rupture life of nickel base superalloys accurately using one set of constants for all the stress levels. The Sinh model exhibits a superior ability to predict the creep behavior using one set of constants for all the stress levels. Finite-element analysis (FEA) on 3D Bridgman notched Waspaloy specimen using the Sinh model is conducted. The results show that the Sinh model when combined with a representative stress equation and calibrated with experimental data can accurately predict the “notch effect” observed in the rupture life of notched specimen. Contour plots of damage evolution and stress redistribution are presented. It is demonstrated that the Sinh model is less stress sensitive, produces unconditional critical damage equal to unity at rupture, exhibits a more realistic damage distribution around the crack tip, and offers better crack growth analysis than KR.

scholarly journals Influence of Post and Resin Cement on Stress Distribution of Maxillary Central Incisors Restored with Direct Resin Composite

10.2341/08-73 ◽  
2009 ◽  
Vol 34 (2) ◽  
pp. 223-229 ◽  
Author(s):  
A. O. Spazzin ◽  
D. Galafassi ◽  
A. D. de Meira-Júnior ◽  
R. Braz ◽  
C. A. Garbin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Resin Composite ◽  
Resin Cement ◽  
Zirconia Ceramic ◽  
Element Analysis ◽  
Fiber Posts ◽  
Stress Levels ◽  
Glass Fiber Posts

Clinical Relevance According to finite element analysis, the zirconia ceramic post created higher stress levels in the post and slightly less in dentin compared with glass fiber posts. Resin cement with a high elastic modulus created higher stress levels in the cement layer. The different film thicknesses of cement did not create significant changes in stress levels.

Damage Evaluation of Grade 91 Thick Cylinder Under Variable Thermal Cyclic Loading Using Continuum Damage Coupled Viscoplastic Models

2019 ◽  
Author(s):  
Nazrul Islam ◽  
Tasnim Hassan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Creep Deformation ◽  
Continuum Damage ◽  
Element Analysis ◽  
Energy Agency ◽  
Creep Fatigue ◽  
Thick Cylinder ◽  
Grade 91

Abstract This study evaluates creep-fatigue damage in the modified Grade 91 thick-cylinder tested by Japan Atomic Energy Agency (JAEA), to understand the failure mechanism of critical components of Fast Reactor nuclear plants. As modified Grade 91 demonstrated creep-fatigue interaction induced failure mechanisms, finite element analysis of high-temperature components will require a unified constitutive model (UCM) that can simulate various creep-fatigue responses with reasonable accuracy. Hence, a UCM coupled with various advanced modeling features including the continuum damage modeling features is investigated to demonstrate their predictability of the fatigue, creep and creep-fatigue responses of the modified Grade 91 steel. The modified UCM is implemented into ABAQUS for analysis of creep deformation in the thick cylinder benchmark problem. Finite element analysis results are presented to demonstrate how the thermal cycling influences the creep-deformation of this high-temperature component. It is also demonstrated how thermal cycling’s influence on fatigue life can be determined based on the damage variable incorporated in the UCM.

Finite element analysis on creep damage

1996 ◽  
Vol 60 (5) ◽  
pp. 781-786 ◽  
Author(s):  
X.N. Wang ◽  
X.C. Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Creep Damage ◽  
Element Analysis

FEM Analysis on Creep Deformation and Axial Bolt Force Change in Threaded Fasteners at Elevated Temperature

2016 ◽  
Author(s):  
Yuya Omiya ◽  
Tadatoshi Watanabe ◽  
Masahiro Fujii ◽  
Haruka Yamamoto
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Elevated Temperature ◽  
Creep Deformation ◽  
Fem Analysis ◽  
Screw Thread ◽  
Element Analysis ◽  
Threaded Fasteners ◽  
The Finite Element Analysis

In this study, the creep deformation in the threaded joint are discussed using a finite element method, and evaluated the influence of the dimensions of bolt and clamped parts. The stress and creep strain distributions are calculated using the Finite Element Analysis. The occurrence and the propagation of the creep deformation and influence of the creep deformation on the axial bolt force were discussed. It was found that the creep deformation occurred at the bearing surfaces and the engagement screw thread mainly at the elevated temperature. The creep deformation was a cause of the reduction in axial bolt force.

scholarly journals Effects of Surface Modification and Bulk Geometry on the Biotribological Behavior of Cross-Linked Polyethylene: Wear Testing and Finite Element Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Kenichi Watanabe ◽  
Masayuki Kyomoto ◽  
Kenichi Saiga ◽  
Shuji Taketomi ◽  
Hiroshi Inui ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Creep Deformation ◽  
Polyethylene Wear ◽  
Wear Testing ◽  
Von Mises Stress ◽  
Cross Linking ◽  
Bearing Surface ◽  
Cobalt Chromium ◽  
Element Analysis

The wear and creep deformation resistances of polymeric orthopedic bearing materials are both important for extending their longevity. In this study, we evaluated the wear and creep deformation resistances, including backside damage, of different polyethylene (PE) materials, namely, conventional PE, cross-linked PE (CLPE), and poly(2-methacryloyloxyethyl phosphorylcholine)- (PMPC-) grafted CLPE, through wear tests and finite element analysis. The gravimetric and volumetric degrees of wear of disks (3 or 6 mm in thickness) of these materials against a cobalt-chromium-molybdenum alloy pin were examined using a multidirectional pin-on-disk tester. Cross-linking and PMPC grafting decreased the gravimetric wear of the PE disks significantly. The volumetric wear at the bearing surface and the volumetric penetration in the backside of the 3-mm thick PE disk were higher than those of the 6-mm thick PE disk, regardless of the bearing material. The geometrical changes induced in the PE disks consisted of creep, because the calculated internal von Mises stress at the bearing side of all disks and that at the backside of the 3-mm thick disks exceeded their actual yield strengths. A highly hydrated bearing surface layer, formed by PMPC grafting, and a cross-linking-strengthened substrate of adequate thickness are essential for increasing the wear and creep deformation resistances.

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