On Fatigue Verification of Class 1 Nuclear Power Piping According to ASME NB-3600

2010 ◽  
Author(s):  
Lingfu Zeng ◽  
Lennart G. Jansson ◽  
Lars Dahlstro¨m
Keyword(s):  
Finite Element ◽  
Nuclear Power ◽  
Numerical Approach ◽  
Cumulative Damage ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Class 1 ◽  
Element Computation ◽  
Computational Procedures ◽  
Finite Element Computation

In this paper, we address fatigue verification of Class 1 nuclear power piping according to ASME Boiler & Pressure Vessel Code Section III (ASME III), NB-3600, and several relevant issues that are often discussed in connection to the power uprate of several Swedish BWR reactors in recent years. We review first the basic requirements and their verifications using finite element analysis in detail. Thereafter, we clarify a so-called simplified elastic-plastic discontinuity analysis for further verification if the basic requirements found unsatisfactory, and examine necessary computational procedures for evaluating alternating stress intensities and cumulative damage factors. Our emphasis is placed on alternative verification procedures, which do not violate the general design principles upon which ASME III NB-3600 is built, when fatigue damage usages predicted by the simplified elastic-plastic discontinuity analysis are unaccepted. An alternative which employs a non-linear finite element computation and a refined numerical approach for re-evaluating the cumulative damage factors is suggested. Concluding remarks are given.

Fatigue Assessment of Class 1 Nuclear Power Piping According to ASME BPV Code: Why Other Alternatives?

2014 ◽  
Author(s):  
Lingfu Zeng ◽  
Lennart G. Jansson
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Intensity ◽  
Nuclear Power ◽  
Element Analysis ◽  
Fatigue Assessment ◽  
Elastic Plastic ◽  
Linear Finite Element ◽  
Non Linear ◽  
Class 1

In this paper, fatigue assessment of Class 1 nuclear power piping according to ASME Boiler and Pressure Vessel Code, Section III, NB-3600, is discussed. Key parameters involved in the fatigue assessment, i.e. the alternating stress intensity Salt, the penalty factor Ke and the cumulative damage factor U, are addressed. In particular, a so-called simplified elastic-plastic discontinuity analysis for alternative verification when basic fatigue requirements found unsatisfactory, and the procedures for evaluating the alternating stress intensity Salt, is reviewed. Factors that can significantly affect the reliability and accuracy of the fatigue assessment are examined. It is illustrated that there is a great need of other alternatives to this simplified elastic-plastic analysis procedure. An alternative based on non-linear finite element analysis is suggested. This paper is a continuation of our work presented in ICONE16-21, which attempted to categorize design rules in the code into linear and non-linear rules and to clarify corresponding requirements that can be used in combination with non-linear finite element analysis.

Application of Neural Networks and Finite Element Computation for Multiscale Simulation of Bone Remodeling

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Ridha Hambli
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Finite Element ◽  
Bone Remodeling ◽  
Multiscale Simulation ◽  
Element Calculation ◽  
Element Analysis ◽  
Element Computation ◽  
Mesoscale Simulations ◽  
Finite Element Computation

In this paper, a novel multiscale hierarchical model based on finite element analysis and neural network computation was developed to link mesoscopic and macroscopic scales to simulate the bone remodeling process. The finite element calculation is performed at the macroscopic level, and trained neural networks are employed as numerical devices for substituting the finite element computation needed for the mesoscale prediction. Based on a set of mesoscale simulations of representative volume elements of bones taken from different bone sites, a neural network is trained to approximate the responses at the meso level and transferred at the macro level.

scholarly journals Field synthesis for the optimal treatment planning in Magnetic Fluid Hyperthermia

2012 ◽  
Vol 61 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Paolo Di Barba ◽  
Fabrizio Dughiero ◽  
Elisabetta Sieni
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Treatment Planning ◽  
Magnetic Fluid ◽  
Optimal Treatment ◽  
Optimal Distribution ◽  
Element Analysis ◽  
Magnetic Fluid Hyperthermia ◽  
Element Computation ◽  
Finite Element Computation

Field synthesis for the optimal treatment planning in Magnetic Fluid HyperthermiaAn automated procedure based on evolutionary computation and Finite Element Analysis (FEA) is proposed to synthesize the optimal distribution of nanoparticles (NPs) in multi-site injection for a Magnetic Fluid Hyperthermia (MFH) therapy. Evolution Strategy and Non dominated Sorting Genetic Algorithm (NSGA) are used as optimization procedures coupled with a Finite Element computation tool.

Interval Finite Element Computation Based on INTLAB for Statical Analysis of Truss Structures with Large Uncertainties

2011 ◽  
Vol 243-249 ◽  
pp. 6955-6955
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Environmental Engineering ◽  
Truss Structures ◽  
Element Analysis ◽  
Interval Approach ◽  
Academic Faculty ◽  
Element Computation ◽  
Institute Of Technology ◽  
Finite Element Computation

Nondeterministic Linear Static Finite Element Analysis: An Interval Approach A Thesis Presented to The Academic Faculty By Hao Zhang School of Civil and Environmental Engineering Georgia Institute of Technology December 2005

Effective thermal elastic plastic finite element computation for welding distortion investigation of pozidriv-type welded structure with rectangular pipes and its mitigation

2020 ◽  
Vol 234 (14) ◽  
pp. 1729-1741
Author(s):  
Jiangchao Wang ◽  
Bin Yi
Keyword(s):  
Finite Element ◽  
Measurement Data ◽  
Displacement Sensor ◽  
Welding Distortion ◽  
Elastic Plastic ◽  
Welded Structure ◽  
Welding Sequence ◽  
Out Of Plane ◽  
Element Computation ◽  
Finite Element Computation

Welding distortion of pozidriv-type welded structure with rectangular pipes by 20 welding passes was examined with experimental and computational approaches, and mitigation techniques were also investigated for precision fabrication. Welding experiment to fabricate pozidriv type welded structure was conducted beforehand, and out-of-plane welding distortion was measured with contact type displacement sensor. Effective thermal elastic plastic finite element computation with iterative substructure method and parallel computation was developed, and then employed to examine the thermal-mechanical response during the entire welding process and predict the residual out-of-plane welding distortion. Good agreement between computed results and measurement data was observed with comparison. The influences of welding sequence and clamping constraint with tack welding on welding distortion were considered, which were also practiced for out-of-plane welding distortion mitigation. Both experiment and finite element computation show that out-of-plane welding distortion with welding sequence optimization and clamping constraint can be significantly reduced with about 38% and 56% magnitude of original welding distortion, respectively, while their mechanisms were also clarified by means of stiffness variation of solving welded structure.

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