T-Stress Estimation by the Two-Parameter Approach for a Specimen with a V-Shaped Notch

2017 ◽  
Keyword(s):  
T Stress ◽  
Stress Estimation ◽  
Parameter Approach ◽  
Two Parameter

T-stress estimation by the two-parameter approach for a specimen with a V-shaped notch

2017 ◽  
Vol 58 (3) ◽  
pp. 546-555 ◽  
Author(s):  
O. Bouledroua ◽  
A. Elazzizi ◽  
M. Hadj Meliani ◽  
G. Pluvinage ◽  
Y. G. Matvienko
Keyword(s):  
T Stress ◽  
Stress Estimation ◽  
Parameter Approach ◽  
Two Parameter

Constraint of Semi-Elliptical Surface Cracks in T and L-Joints

2006 ◽  
Vol 326-328 ◽  
pp. 939-944
Author(s):  
Hyung Yil Lee ◽  
Yun Jae Kim
Keyword(s):  
Finite Element ◽  
Structural Characteristics ◽  
Pressure Vessels ◽  
Surface Cracks ◽  
Spring Model ◽  
Constraint Effect ◽  
T Stress ◽  
Line Spring Model ◽  
Parameter Approach ◽  
Two Parameter

Critical defects in pressure vessels and pipes are generally found in the form of a semielliptical surface crack, and the analysis of which is consequently an important issue in engineering fracture mechanics. Furthermore, in addition to the traditional single parameter K or J-integral, the second parameter like T-stress should be measured to quantify the constraint effect. In this work, the validity of the line-spring model is investigated by comparing line-spring J-T solutions to the reference 3D finite element J-T solutions. A full 3D-mesh generating program for semi-elliptical surface cracks is employed to provide such reference 3D solutions. Then some structural characteristics of the surface-cracked T and L-joints are studied by mixed mode line-spring finite element. Negative T-stresses observed in T and L-joints indicate the necessity of J-T two parameter approach for analyses of surface-cracked T and L-joints.

scholarly journals A Simplified SSY Estimate Method to Determine EPFM Constraint Parameter for Sensor Design

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 717
Author(s):  
Ping Ding ◽  
Xin Wang
Keyword(s):  
Loading Condition ◽  
Biaxial Loading ◽  
External Loading ◽  
Small Scale ◽  
Cracked Plate ◽  
T Stress ◽  
Estimate Method ◽  
Parameter Values ◽  
Parameter Approach ◽  
Two Parameter

To implement a sensor structure analysis and design (as well as other engineering applications), a two-parameter approach using elastic–plastic fracture mechanics (EPFM) could be applied to analyze a structure more accurately than a one-parameter approach, especially for structures with low crack constraint. The application of the J-A two-parameter approach on sensors and other structures depends on the obtainment of a constraint parameter A. To conveniently and effectively obtain the A parameter values, the authors have developed a T-stress-based estimate method under a small-scale yielding (SSY) condition. Under a uniaxial external loading condition, a simplified format of the T-stress-based estimate has been proposed by the authors to obtain the parameter A much more conveniently and effectively. Generally, sensors and other practical engineering structures endure biaxial external loading instead of the uniaxial one. In the current work, the simplified formation of the estimate method is extended to a biaxial loading condition. By comparing the estimated A parameter values with their numerical solutions from a finite element analysis (FEA) results, the extension of the simplified formation of T-stress-based estimate method to biaxial loading was discussed and validated. The comparison procedure was completed using a wide variety of materials and geometrical properties on three types of specimens: single edge cracked plate (SECP), center cracked plate (CCP), and double edge cracked plate (DECP).

Multiaxial Fatigue Failure Criterion Considering Formation and Growth of Small Cracks

2010 ◽  
Author(s):  
Yukio Takahashi
Keyword(s):  
Life Prediction ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
New Approach ◽  
Small Cracks ◽  
Failure Life ◽  
Parameter Approach ◽  
Realistic Prediction ◽  
Two Parameter

Treatment of stress multiaxiality in fatigue assessment is practically important in many components subjected to cyclic loading during their operation. Based on the results of fatigue tests on hollow and solid bar specimens of SUS316NG and SGV410 under various combinations of axial and torsional stresses, accuracy of fatigue life prediction based on the conventional parameters as well as a two parameter approach newly proposed here was studied. The conventional parameters tended to provide conservative prediction of the failure life for shear-dominated cases especially for SUS316NG while the new approach was able to give more realistic prediction of failure lives.

Grain Growth during Annealing: Experiments and Modelling

2012 ◽  
Vol 715-716 ◽  
pp. 611-616 ◽  
Author(s):  
M. Candic ◽  
Bao Hui Tian ◽  
Christof Sommitsch
Keyword(s):  
Grain Growth ◽  
Second Phase ◽  
Excellent Correlation ◽  
Grain Sizes ◽  
Second Phase Particles ◽  
Different Temperatures ◽  
Grain Growth Kinetics ◽  
Parameter Approach ◽  
Annealing Experiments ◽  
Two Parameter

In the present work, for the description of grain coarsening, a probabilistic and a deterministic 2D cellular automaton simulation setup were developed. The results of the simulation have been validated by solution annealing experiments of austenitic stainless steel 304L (Fe-18Cr-8Ni) at different temperatures and times. Both cellular automata models show an excellent correlation between the experimental determined data and grain growth kinetics based upon considerations of temperature and second phase particles. Additionally, a two parameter approach of the probabilistic model was implemented, resulting in determining the grain sizes limiting normal and abnormal grains and accurate description of grain growth.

Critical Strain Energy Density along the Curved Front of the Growing Fatigue Crack

2005 ◽  
Vol 482 ◽  
pp. 307-310
Author(s):  
Tomáš Denk ◽  
Vladislav Oliva ◽  
Aleš Materna
Keyword(s):  
Fracture Mechanics ◽  
Fatigue Cracks ◽  
Anomalous Behavior ◽  
Fatigue Threshold ◽  
Stress Constraint ◽  
Short Cracks ◽  
T Stress ◽  
Residual Fatigue ◽  
Two Parameter ◽  
Different Levels

A two-parameter constraint-based fracture mechanics approach is used to explain the effect of the constraint on the apparently anomalous behavior of short fatigue cracks. The different levels of stress constraint are quantified by the T-stress, and microstructurally as well as mechanically short cracks are discussed. Short cracks generally behave more sensitively to the constraint than the long ones. It is shown that in most cases, the existence of short cracks goes hand in hand with an intrinsic loss of the constraint, which contributes to a decrease of their fatigue threshold values and accelerates their growth. In this paper, the above effect is quantified and conclusions concerning the applicability of the fracture mechanics parameters and approaches to the estimation of the residual fatigue life of structures are discussed.

Two Parameter Description of Crack Tip Stress Fields for Wedge Splitting Test Specimen: Influence of Wedge Angle

2014 ◽  
Vol 969 ◽  
pp. 345-350
Author(s):  
Stanislav Seitl ◽  
Carlos Bermejo ◽  
Jakub Sobek ◽  
Václav Veselý
Keyword(s):  
Wedge Angle ◽  
Crack Tip ◽  
Stress Fields ◽  
Finite Element Software ◽  
Wedge Splitting Test ◽  
Splitting Test ◽  
T Stress ◽  
Two Parameter ◽  
Crack Tip Stress ◽  
Wedge Splitting

Two parameter fracture mechanics uses for description of the crack tip stress fields, not only the stress intensity factor (SIF), but the second term of Williams expansion the T-stress. In the paper, the SIF and T-stress of typical wedge splitting specimens with usual loading arrangements varying in the wedge angle are directly computed using ANSYS finite element software. The influence of the wedge angle value is quantified.

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