scholarly journals Design and Fabrication of Portable Weld Residual Stress Measuring Device using MBN Principle

2020 ◽  
Vol 2 (3) ◽  
pp. 70
Author(s):  
C.E Etin-Osa ◽  
J.I. Achebo ◽  
K. O. Obahiagbon
Keyword(s):  
Residual Stress ◽  
Measuring Device ◽  
Weld Residual Stress ◽  
Stress Measuring

Development of a Residual Stress Simulation Benchmark for a Single Bead-on-Plate Weldment

2006 ◽  
Author(s):  
Peter J. Bouchard ◽  
Lyndon Edwards ◽  
Anastasius G. Youtsos ◽  
Roger Dennis
Keyword(s):  
Residual Stress ◽  
Assessment Procedure ◽  
Defect Assessment ◽  
Best Estimate ◽  
Weld Residual Stress ◽  
Single Bead ◽  
Stress Prediction ◽  
Stainless Steel Bead ◽  
Stress Simulation ◽  
Network Project

Finite element weld residual stress modelling procedures involve complex non-linear analyses where many assumptions and approximations have to be made by the analyst. Weld modelling guidelines for inclusion in the R6 defect assessment procedure are in preparation and will be accompanied by a series of validation benchmarks that can be used to evaluate the accuracy of weld modelling procedures and assess their suitability for use in fracture assessments. It is intended to base one of the benchmarks on a stainless steel bead-on-plate weldment that has been extensively studied by members of Task Group 1 of the NeT European Network project. This paper uses round robin residual stress measurements from the NeT project to derive a statistically based ‘best estimate’ distribution of transverse stress passing through the wall-section at mid-length of the bead-on-plate weldment. The accuracy of a state-of-the-art residual stress prediction is benchmarked against the best estimate measurements using a root mean square error analysis and comparisons of decomposed components of stress. The appropriateness of using the predicted residual stresses in fracture assessments is assessed by comparing stress intensity factors based on the measured and predicted distributions of stress. The results from these studies will be used to help establish accuracy targets and acceptance criteria for the welding benchmark.

Two Case Studies in 3-D Residual Stress Prediction for Nuclear Power Applications

2016 ◽  
Author(s):  
Michael L. Benson ◽  
Patrick A. C. Raynaud ◽  
Frederick W. Brust
Keyword(s):  
Residual Stress ◽  
Nuclear Power ◽  
Three Dimensional ◽  
Repair Process ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Weld Residual Stress ◽  
Plant Operations ◽  
Stress Prediction ◽  
Residual Stress Modeling

Residual stress prediction contributes to nuclear safety by enabling engineering estimates of component service lifetimes. Subcritical crack growth mechanisms, in particular, require residual stress assumptions in order to accurately model the degradation phenomena. In many cases encountered in nuclear power plant operations, the component geometry permits two-dimensional (i.e., axisymmetric) modeling. Two recent examples, however, required three-dimensional modeling for a complete understanding of the weld residual stress distribution in the component. This paper describes three-dimensional weld residual stress modeling for two cases: (1) branch connection welds off reactor coolant loop piping and (2) a mockup to demonstrate the effectiveness of the excavate and weld repair process.

Weld Residual Stress in Large Diameter Nuclear Nozzles

2011 ◽  
Author(s):  
Tao Zhang ◽  
F. W. Brust ◽  
Gery Wilkowski
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Nuclear Power ◽  
Kinematic Hardening ◽  
Large Diameter ◽  
Thick Wall ◽  
Isotropic Hardening ◽  
Residual Stress Field ◽  
Mixed Hardening ◽  
Weld Residual Stress

Weld residual stresses in nuclear power plant can lead to cracking concerns caused by stress corrosion. These are large diameter thick wall pipe and nozzles. Many factors can lead to the development of the weld residual stresses and the distributions of the stress through the wall thickness can vary markedly. Hence, understanding the residual stress distribution is important to evaluate the reliability of pipe and nozzle joints with welds. This paper represents an examination of the weld residual stress distributions which occur in various different size nozzles. The detailed weld residual stress predictions for these nozzles are summarized. Many such weld residual stress solutions have been developed by the authors in the last five years. These distributions will be categorized and organized in this paper and general trends for the causes of the distributions will be established. The residual stress field can therefore feed into a crack growth analysis. The solutions are made using several different constitutive models such as kinematic hardening, isotropic hardening, and mixed hardening model. Necessary fabrication procedures such as repair, overlay and post weld heat treatment are also considered. Some general discussions and comments will conclude the paper.

On the Mechanics of Residual Stresses in Girth Welds

2006 ◽  
Vol 129 (3) ◽  
pp. 345-354 ◽  
Author(s):  
P. Dong
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Relative Importance ◽  
Stress Distributions ◽  
Unified Framework ◽  
Joint Geometry ◽  
Weld Residual Stress ◽  
Girth Welds ◽  
Welding Procedure

In this paper, some of the important controlling parameters governing weld residual stress distributions are presented for girth welds in pipe and vessel components, based on a large number of residual stress solutions available to date. The focus is placed upon the understanding of some of the overall characteristics in through-wall residual stress distributions and their generalization for vessel and pipe girth welds. In doing so, a unified framework for prescribing residual stress distributions is outlined for fitness-for-service assessment of vessel and pipe girth welds. The effects of various joint geometry and welding procedure parameters on through thickness residual stress distributions are also demonstrated in the order of their relative importance.

Validation Approaches for Weld Residual Stress Simulation

2014 ◽  
Author(s):  
Michael R. Hill ◽  
Minh N. Tran ◽  
John E. Broussard
Keyword(s):  
Residual Stress ◽  
Crack Growth ◽  
Model Validation ◽  
Round Robin ◽  
Plant Management ◽  
Crack Growth Behavior ◽  
Stress Model ◽  
Consensus Approach ◽  
Cracking Behavior ◽  
Weld Residual Stress

In assessment of stress corrosion cracking behavior of susceptible welded materials, the contribution of weld residual stress is a key input for stress intensity factor calculations, which in turn are used to determine anticipated crack growth and to plan for inspection or repair. Without accurate weld residual stress information, it is challenging to develop an optimal plan for plant management. Weld residual stress simulations, based on non-linear finite element computations, provide a means to estimate residual stresses in components. However, there is no established, consensus approach for weld residual stress model validation, which could be used to judge model quality, specifically with respect to the influence of residual stress output on plant management decisions. A consensus model validation approach would benefit a broad range of stakeholders in pressure vessel technology. The paper provides technical detail of example approaches for weld residual stress model validation, and applies these approaches to a set of weld residual stress model outputs that were developed in the context of an industry round robin. The set of outputs is from Phase 2a of the international round robin organized cooperatively by the U.S. Nuclear Regulatory Commission and the Electric Power Research Institute. Example validation approaches include comparisons of output from one model with output from other models, as well as comparisons of model output with data from residual stress measurements. The figures of merit used for comparisons range from simple (e.g., evaluation of mechanical section forces) to complex (e.g., comparison of predicted crack growth behavior). Applying a range of validation approaches provides information for use within the technical community, to support development of a consensus approach for weld residual stress model validation.

The Experimental Study of Diffraction Angle of Aluminum Alloy 3003

2012 ◽  
Vol 625 ◽  
pp. 291-296
Author(s):  
Neng Quan Duan ◽  
Jian Liang Ren ◽  
Rui Qiang Pang
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Stress Measurement ◽  
Electrical Measuring ◽  
Diffraction Method ◽  
Measuring Method ◽  
X Ray ◽  
Equal Strength ◽  
Diffraction Angle ◽  
Stress Measuring

The most suitable diffraction angle of aluminum alloy 3003 used for stress measuring is aimed to be determined in this paper. The experiment makes a stress measurement of a loading aluminum alloy 3003 equal strength beam with the traditional electrical measuring method and the X-ray stress measurement. With the electrical measuring method as reference, the research study the measured values that acquired from the X-ray diffraction method when the diffraction angle are 142° and 156°, and then compare them with that acquired from electrical measuring method. The measurement results demonstrate that the diffraction angle at 156 ° is better than at 142 ° based on the assessment standards of the liner slope and the distribution of data. Thus the optimum diffraction angle for X-ray to measure the macroscopic stress of aluminum alloy 3003 is 156 °. In this paper，the stress caused by the load on the equal strength beam is assumed to be "residual stress" and thus the conclusion has reference values for the standardization of residual stress measurement of aluminum alloy by XRD and has theoretical guiding significance in the production practices.

Sign in / Sign up

Export Citation Format

Share Document