Fracture Evaluation of Ni-Based Alloy Weld Joint of Cylindrical Model Subjected to 4-Point Bending or Inner Pressure

2011 ◽  
Author(s):  
Kazuo Ogawa ◽  
Kiminobu Hojo ◽  
Itaru Muroya ◽  
Youichi Iwamoto ◽  
Naoki Ogawa
Keyword(s):  
Weld Joint ◽  
Room Temperature ◽  
Evaluation Method ◽  
Limit Load ◽  
Initial Surface ◽  
Inner Pressure ◽  
Maximum Test ◽  
Bending Load ◽  
Load Evaluation ◽  
Alloy Weld

For the purpose of establishing fracture evaluation method of nickel based alloy weld of nuclear power plants, fracture tests using pipe models (8B and 14B for bending, 12B for inner pressure) with an alloy 132 weld joint have been performed at room temperature and high temperature (325°C). The predicted loads calculated by limit load evaluation method using the measured and code regulated flow stresses were compared with the maximum test loads. And the predicted bending loads of the pipes at 325°C (8B and 14B) and at room temperature (8B) with the initial surface crack whose depth is 75% of the pipe thickness were in good agreement with the maximum test loads. Also the predicted inner pressure of the pipe at room temperature (12B) agreed with the measured maximum pressure. Only for one case of the 14B pipe subjected to the bending load at room temperature, the predicted load by limit load evaluation method has 20% unconservative difference from the measured data, on the other hand, the predicted load by J-T analysis made this difference smaller and conservative.

Application of Gurson Model to Ni-Based Alloy Weld Joint Pipe With an Axial or a Circumferential Surface Flaw

2012 ◽  
Author(s):  
Kiminobu Hojo ◽  
Naoki Ogawa
Keyword(s):  
Weld Joint ◽  
Room Temperature ◽  
Surface Flaw ◽  
Test Model ◽  
Initial Surface ◽  
Test Results ◽  
Plate Model ◽  
Gurson Model ◽  
Pipe Model ◽  
Test Result

The previous paper[1] reported the fracture test results using pipe models (8B and 14B for bending) with an alloy 132 weld joint at room temperature and high temperature (325degC). The predicted loads by limit load evaluation method of the pipes at 325 deg C (8B and 14B) and at room temperature (8B) with the initial surface flaw whose depth is 75% of the pipe thickness were in good agreement with the maximum test loads. However 14B pipe at room temperature, the predicted load has 20% unconservative difference from the measured data. To predict the different fracture behavior or fracture mode of the same welding material at a flaw location with different flaw or model geometry by numerical procedure without large sized test model, Gurson model[2] was applied on trial to the two types of the pipe models with a circumferential or an axial flaw and one plate model for simplification for the case of the pipe with an axial flaw. As a result the plate model predicted the penetration pressure of the pressure test of the pipe with an axial flaw with 1.3times larger than the test result, while the pipe model with an axial flaw over-predicted the test result by 1.45 times. On the other hand the maximum load around crack penetration of the pipe model with a circumferential flaw was 0.9 times of the test results. Discussions for application of Gurson model were made.

scholarly journals In-situ reactions and mechanical properties of 6061 aluminum alloy weld joint with SiCp by laser melting injection

2021 ◽  
Vol 203 ◽  
pp. 109538
Author(s):  
Boan Xu ◽  
Ping Jiang ◽  
Shaoning Geng ◽  
Yilin Wang ◽  
Jintian Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Weld Joint ◽  
Laser Melting ◽  
6061 Aluminum Alloy ◽  
In Situ Reactions ◽  
Alloy Weld

The Evolution of Contact Stress and Surface Profile in Press-Fitted Shaft under Partial Slip Conditions

2006 ◽  
Vol 321-323 ◽  
pp. 1495-1498 ◽  
Author(s):  
Dong Hyung Lee ◽  
Seok Jin Kwon ◽  
Chan Woo Lee ◽  
Jae Boong Choi ◽  
Young Jin Kim
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Surface Profile ◽  
Contact Stresses ◽  
Fretting Wear ◽  
Partial Slip ◽  
Initial Surface ◽  
Slip Conditions ◽  
Bending Load ◽  
Element Method

In this paper the fretting wear of press-fitted specimens under partial slip conditions was simulated using finite element method and numerical analysis based on Archard's equation. An elasto-plastic analysis of contact stresses in a press-fitted shaft in contact with a boss was conducted with finite element method and the amount of microslip and contact pressure due to bending load was estimated. The predicted wear profile of press-fitted specimens at the contact edge was compared with the experimental results. It is found that the depth of fretting wear by repeated slip between shaft and boss reaches the maximum value at the contact edge. The initial surface profile is continuously changed by the wear at the contact edge, and then the corresponding contact stresses and strain are redistributed.

scholarly journals OS0820 Plastic collapse strength and maximum load evaluation method of flawed stainless piping subjected to axial tension and bending

2012 ◽  
Vol 2012 (0) ◽  
pp. _OS0820-1_-_OS0820-2_
Author(s):  
Seiji YANAGIHARA ◽  
Masaaki MATSUBARA ◽  
Ryousuke SUZUKI ◽  
Masato SUZUKI ◽  
Taisuke SHIRAISHI ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Maximum Load ◽  
Plastic Collapse ◽  
Axial Tension ◽  
Collapse Strength ◽  
Load Evaluation

On applicability of MQ-RPIM and MLPG meshless methods with 3D extended-enriched base functions for estimation of mode I stress intensity factor and fatigue crack growth in cyclic tensile and bending load of an un-notched and notched shaft

2021 ◽  
pp. 030932472110384
Author(s):  
Behrooz Ariannezhad ◽  
Shahram Shahrooi ◽  
Mohammad Shishehsaz
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Meshless Method ◽  
Solid Mechanics ◽  
Meshless Methods ◽  
Initial Surface ◽  
Intensity Factors ◽  
Penalty Factor ◽  
Bending Load ◽  
Base Functions

In this study, a numerical meshless method is used to solve the weak form of the linear elastic equations in solid mechanics. Evaluation and comparison of the numerical meshless methods have been carried out via the radial point interpolation meshless method with multi-quadrics base functions (MQ-RPIM) and meshless local Petrov-Galerkin method (MLPG). Using these two methods, stress intensity factors in an elastic medium containing geometric discontinuities and cracks are estimated based on tensile and bending cyclic loading. The analysis domain has been identified via three-dimensional modeling of the notched and un-notched shafts with an initial surface semi-elliptical crack subjected to tensile or bending cyclic loadings. To enhance the accuracy of calculations, the RPIM meshless method is applied using polynomial and extended-enriched 3D base functions. Shape functions have been developed using standard and optimal parameters and values with Mono-Objective Function in PSO algorithm. In the MLPG meshless method with the extended-enriched functions, discretization is performed via direct and penalty factor methods, to reach more efficient results and meet the boundary conditions. Efficiency comparison of the selected numerical methods with the experimental findings and the numerical analysis of finite elements method indicates that in comparison with the MLPG method, MQ-RPIM enriched meshless method can be utilized with fewer nodes in the analysis domain while reaching the accuracy and convergence with lower stress intensity factors and gentler slope. However, the processing time of the MLPG meshless method is lower than that of the other methods.

Application of Gurson Model to Ni-Based Alloy Weld Joint Pipe With an Axial or a Circumferential Surface Flaw: Phase II

2013 ◽  
Author(s):  
Kiminobu Hojo ◽  
Daigo Watanabe
Keyword(s):  
Phase Ii ◽  
Weld Joint ◽  
Surface Flaw ◽  
Test Results ◽  
Fracture Test ◽  
Gurson Model ◽  
Dissimilar Metal ◽  
Fracture Behaviors ◽  
Parameter Values ◽  
Alloy Weld

The previous paper ASME PVP2012[1] reported application of Gurson model to the fracture test results using pipe models with part-through wall cracks on the dissimilar metal (DM) welds. The predicted maximum loads and the crack behaviors after penetration did not agree well. These results may originate from improper parameter values of Gurson model. This paper revised these parameters and improved the estimated fracture behaviors of the pipe models. A suitable fitting process of Gurson parameters was also proposed.

Introduction of CASS Pipe Flaw Evaluation of JSME Rules on Fitness for Service

2019 ◽  
Author(s):  
Kiminobu Hojo
Keyword(s):  
Stainless Steel ◽  
Evaluation Method ◽  
Limit Load ◽  
Evaluation Procedure ◽  
Screening Criteria ◽  
Steel Pipes ◽  
Evaluation Procedures ◽  
Degradation Models ◽  
Fracture Tests ◽  
Cast Stainless Steel

Abstract This paper summarizes the revised flaw evaluation procedures for cast austenitic stainless steel (CASS) pipe of the Japan Society of Mechanical Engineers (JSME) rules on fitness for service (FFS) in 2018 addenda. The revision includes the introduction of thermal aging degradation models for stressstrain curve and fracture resistance (J-R) curve, application of a screening criteria for the fracture evaluation procedure of cast stainless steel pipes, and introduction of a new critical stress parameter for the limit load evaluation method of a shallow flaw with a flaw depth to thickness ratio of less than or equal to 0.5. These revisions are based on a large database of specimen tests and several fracture tests of flat plate and large pipe models using thermally aged material, which have already been published.

A Simplified Thermal Load Evaluation Method for Localized Lug Stresses Beyond Sec. III Appendix-Y

2019 ◽  
Author(s):  
Tsubasa Matsumiya ◽  
Daniel Garcia-Rodriguez ◽  
Akira Nebu ◽  
Noriyuki Takamura
Keyword(s):  
Thermal Stresses ◽  
Evaluation Method ◽  
Three Dimensional ◽  
Parameter Study ◽  
Element Analysis ◽  
Class 1 ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
Three Dimensional Finite Element ◽  
Load Evaluation

Abstract In this work an evaluation method for local thermal stresses on class 1 piping due to U-shaped lugs is presented. First, a three-dimensional finite element analysis (3D-FEA) is used to perform a thermal transient evaluation, obtaining the time-dependent temperature distribution of a realistic range of pipe-lug systems. These results are then used as an input for both a structural 3D-FEA and the corresponding thermal stress term in Non-Mandatory Appendix Y [1]. It was seen that the formula in Appendix-Y cannot account for the thermal stresses obtained through the detailed FEA evaluation. A parameter study using a simplified two-dimensional (2D) FEA approach, shows that the localized thermal stresses due to lugs are significantly affected by: (1) pipe-to-lug thickness ratio, (2) distance between adjacent lugs, and (3) lug height. A set of correction coefficients depending on these parameters is therefore proposed. When applying the proposed correction coefficients to the Appendix Y method, adequately conservative (when compared with 3D FEA results) stresses can be obtained. Since these correction coefficients can be obtained from simple geometric considerations, the proposed method successfully accounts for the complex lug-to-lug interaction while retaining the simplicity of the original Appendix Y approach.

Shakedown and Limit Analysis of Kinematic Hardening Piping Elbows Under Inner Pressure and Bending Moments

2020 ◽  
Author(s):  
Heng Peng ◽  
Yinghua Liu
Keyword(s):  
Yield Strength ◽  
Limit Analysis ◽  
Kinematic Hardening ◽  
Limit Load ◽  
Bending Moments ◽  
Plastic Limit ◽  
Inner Pressure ◽  
Plastic Limit Load ◽  
Interaction Curves ◽  
Shakedown Limit

Abstract The stress compensation method (SCM) for shakedown and limit analysis was previously proposed and applied to elastic-perfectly plastic (EPP) piping elbows. In this paper, the SCM is extended to account for limited kinematic hardening (KH) material model based on the extended Melan’s static shakedown theorem using a two-surface model defined by two hardening parameters: initial yield strength and ultimate yield strength. To validate the extended SCM, a numerical test on a cylinder pipe is performed. The results agree well with ones from literature. Then the extended SCM is applied to the shakedown and limit analysis of KH piping elbows subjected to inner pressure and cyclic bending moments. Various loading combinations are investigated to create the shakedown limit and plastic limit load interaction curves. The effects of the material hardening, angle of the elbow and loading conditions on the shakedown limit and plastic limit load interaction curves are presented and analysed. The present method is incorporated in the commercial software of Abaqus and can be considered as a general computational tool for shakedown analysis of KH engineering structures. The obtained results provide a useful information for the structural design and integrity assessment of practical piping elbows.

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