Fitness for Service Assessment on Local Metal Loss Near a Discontinuity Using Elastic-Plastic Stress Analysis

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Zhanghai (John) Wang ◽  
Samuel Rodriguez
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Plastic Material ◽  
Material Model ◽  
Metal Loss ◽  
Technical Approach ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Structural Discontinuity ◽  
Elastic Plastic Material

In fitness for service (FFS) assessments, one issue that people often encounter is a corroded area near a structural discontinuity. In this case, the formula-based sections of the FFS standard are incapable of evaluating the component without resorting to finite element analysis (FEA). In this paper, an FEA-based technical approach for evaluating FFS assessments using an elastic-plastic material model and reformed criteria is proposed.

Elastic—plastic finite element analysis of short flat bars with projections part 2: Axial loading

1996 ◽  
Vol 31 (1) ◽  
pp. 25-33 ◽  
Author(s):  
S J Hardy ◽  
M K Pipelzadeh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Plastic Material ◽  
Axial Loading ◽  
Material Model ◽  
Shear Loading ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Elastic Plastic Material ◽  
Stress Concentration Factors

This paper describes the results of a study of the elastic–plastic behaviour of short flat bars with projections subjected to monotonic and cyclic axial loading using finite element analysis. The results are complementary to similar results for (a) shear loading and (b) combined axial and shear loading. Six geometries are considered and elastic–plastic stress and strain data for both local and remote restraints are presented. These geometries and associated restraints result in elastic stress concentration factors in the range 1.69–4.96. A simple bilinear elastic–plastic material model is assumed and the results are normalized with respect to material properties so that they can be applied to geometrically similar components made from other materials which can be represented by the same material models.

Elastic and elastic-plastic finite element analysis of hollow tubes with axisymmetric internal projections under combined axial and pressure loading

2001 ◽  
Vol 36 (4) ◽  
pp. 373-390 ◽  
Author(s):  
S. J Hardy ◽  
M. K Pipelzadeh ◽  
A. R Gowhari-Anaraki
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Plastic Material ◽  
Axial Loading ◽  
Material Model ◽  
Pressure Loading ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Applied Loading

This paper discusses the behaviour of hollow tubes with axisymmetric internal projections subjected to combined axial and internal pressure loading. Predictions from an extensive elastic and elastic-plastic finite element analysis are presented for a typical geometry and a range of loading combinations, using a simplified bilinear elastic-perfectly plastic material model. The axial loading case, previously analysed, is extended to cover the additional effect of internal pressure. All the predicted stress and strain data are found to depend on the applied loading conditions. The results are normalized with respect to material properties and can therefore be applied to geometrically similar components made from other materials, which can be represented by the same material models.

Elastic—plastic finite element analysis of short flat bars with projections part 1: Shear loading

1996 ◽  
Vol 31 (1) ◽  
pp. 9-24 ◽  
Author(s):  
S J Hardy ◽  
M K Pipelzadeh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Plastic Material ◽  
Shear Loading ◽  
Element Analysis ◽  
Cyclic Shear ◽  
Elastic Plastic ◽  
Concentration Factors ◽  
Elastic Plastic Material ◽  
Stress Concentration Factors

This paper describes the results of a study of the elastic–plastic behaviour of short flat bars with projections subjected to monotonic and cyclic shear loading using finite element analysis. Six geometries, associated with both local and remote restraints (resulting in elastic stress concentration factors in the range 1.90–7.20), are considered. Three simple bilinear elastic–plastic material models are assumed. The results have been normalized with respect to material properties so that they can be applied to geometrically similar components made from other materials which can be represented by the same materials models.

Finite Element Analysis of Elastic-Plastic Concentrated Contact

2015 ◽  
Vol 662 ◽  
pp. 65-68 ◽  
Author(s):  
Dušan Zíta ◽  
Jaroslav Menčík
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Outer Region ◽  
Spherical Body ◽  
Relative Depth ◽  
Depth Of Penetration ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Loading And Unloading ◽  
Elastic Plastic Material

The Paper Shows Results of the Finite Element Modelling of Contact of a Rigid Spherical Body (indenter) with a Body from Elastic-Plastic Material. both the Proces of Loading and Unloading are Modelled. in Addition to Stresses, Also Energies are Investigated, Including their Distribution in the Plastically Deformed Core and the Elastically Deformed Outer Region. Attention is Devoted to Residual Stresses and Energies as well. Influence of Various Factors is Investigated, such as Various Values of Strain-Hardening Parameters (e.g. in Johnson-Cook Model), Relative Depth of Penetration (h/R), Coefficient of Friction.

A Practical Analysis Framework for Assessment of Printed Circuit Heat Exchangers in High Temperature Nuclear Service

2021 ◽  
Author(s):  
Avinash Shaw ◽  
Heramb Mahajan ◽  
Tasnim Hassan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Heat Exchangers ◽  
Plastic Material ◽  
Material Model ◽  
Analysis Framework ◽  
Element Analysis ◽  
Printed Circuit ◽  
Analysis Technique

Abstract Printed Circuit Heat Exchangers (PCHEs) have high thermal efficiency because of the numerous minuscule channels. These minuscule channels result in a high thermal exchange area per unit volume, making PCHE a top contender for an intermediate heat exchanger in high-temperature reactors. Thousands of minuscule channels make finite element analysis of the PCHE computationally infeasible. A two-dimensional analysis is usually performed for the PCHE core, which cannot simulate the local channel level responses reasonably because of the absence of global constraint influence. At present, there is no analysis technique available in the ASME Code or literature that is computationally efficient and suitable for engineers to estimate PCHE local responses. A novel but practical two-step analysis framework is proposed for performing PCHE analysis. In the first step, the channeled core is replaced by orthotropic solids with similar stiffness to simulate the global thermomechanical elastic responses of the PCHE. In the second step, local submodel analysis with detailed channel geometry and loading is performed using the elastic-perfectly plastic material model. The proposed two-step analysis technique provides a unique capability to estimate the channel corner responses to be used for PCHE performance assessment. This study first developed a methodology for calculating the elastic orthotropic properties of the PCHE core. Next, the two-step analysis is performed for a realistic size PCHE core, and different issues observed in the results are scrutinized and resolved. Finally, a practical finite element analysis framework for PCHEs in high-temperature nuclear service is recommended.

Some factors affecting the loosening failure of bolted joints under vibration using finite element analysis

2017 ◽  
Vol 232 (21) ◽  
pp. 3942-3953 ◽  
Author(s):  
Hao Gong ◽  
Jianhua Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Frequency ◽  
Plastic Material ◽  
Material Model ◽  
Element Model ◽  
Bolted Joints ◽  
Vibration Parameter ◽  
Element Analysis ◽  
Loosening Rate

Finite element analysis has been regarded as an effective research method for analyzing the loosening failure of bolted joints under vibration. However, there exist some factors, which influence the accuracy and reliability of loosening results, thus determining the explanations of the loosening mechanism. In this study, a 3D finite element model of a typical bolted joint was built to investigate the effects of several different factors on the loosening under transverse vibration loading. These influencing factors include preload generation, vibration parameter, and material model. Based on the simulation results, it was found that applying the method of pretension element to generate preload instead of the actual method of torque was reliable and efficient. For the vibration parameter, it showed that the decrease rate in preload was higher for a larger vibration amplitude. But once the bearing surface reached complete slip, the loosening rate would keep constant. This was because the thread surface at that time reached a sticking state. Vibration frequency was proved to have no effect on the loosening behavior. This result demonstrated that the quasi-static assumption for vibration frequency was reasonable. Additionally, it also indicated that plastic material models only affected the preload loss in the initial several vibration cycles and had no influence on the loosening rate of preload after several vibration cycles. Finally, experiments were conducted to confirm qualitatively the results obtained based on finite element analysis.

Investigation on Braced Excavation Using Elastic-Plastic Material

2014 ◽  
Vol 1079-1080 ◽  
pp. 327-332
Author(s):  
Hsi Chi Yang
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Solution Technique ◽  
Soil Behavior ◽  
Element Analysis ◽  
Field Problem ◽  
Elastic Plastic ◽  
Simulation Techniques ◽  
Elastic Plastic Material ◽  
Soil Excavation

Finite element method has been used to study the behavior of soil excavation. The solutions were generally obtained assuming linear elastic soil behavior. However, this paper treats the soil as an elastic-plastic medium. The simulation techniques used in the braced field excavation are presented first and then, in order that a converged solution can be obtained, an iteration solution technique called the mixed stiffness method is used in the incremental nonlinear finite element analysis of the field problem where the soil behavior is simulated as elastic-plastic by employing the Drucker-Prager model. The solution techniques and procedure presented can be applied to future soil excavation problems.

Sign in / Sign up

Export Citation Format

Share Document