An FEA Investigation Into Ratchetting Induced Purely by Cyclic Thermal Loading

2014 ◽  
Author(s):  
Conor S. Campbell ◽  
Donald Mackenzie
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Thermal Loading ◽  
Plastic Material ◽  
Lead Author ◽  
Element Analysis ◽  
Linear Temperature ◽  
Cyclic Thermal Loading ◽  
Elastic Plastic ◽  
Model Structures

A detailed finite element investigation of the cyclic elastic-plastic response of three model structures subject to thermal and mechanical loading is presented within the context of ASME B&PV Code Section VIII Division 2 design requirements. The model structures are a thin tube subject to constant internal pressure and a cyclic through-thickness linear temperature gradient (the Bree problem), a three bar system subject to cyclic thermal loading only and an intermediate thickness tube subject to internal pressure and an axially moving cyclic temperature wave. Incremental elastic-plastic finite element analysis assuming an elastic-perfectly-plastic material model and small deformation theory is performed for each model structure and ratchet and shakedown boundaries determined by application of a bisection method. Results are compared with ASME VIII ratcheting assessment procedures. The results show that in the Bree problem ratcheting does not occur under thermal loading alone, as expected, however for the two other sample structures it is shown that ratchetting can occur under thermal loading for structures subject to specific deformation constraints. The lead author is an MS level student at the University of Strathclyde.

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.

Computation of Ratchet Limits for Structures Subjected to Cyclic Loading and Temperature

2002 ◽  
Author(s):  
A. R. S. Ponter ◽  
H. Chen ◽  
M. Habibullah
Keyword(s):  
Finite Element ◽  
Cyclic Loading ◽  
Mechanical Loading ◽  
Limit Theorems ◽  
Thermal Loading ◽  
Loading History ◽  
Cyclic Thermal Loading ◽  
Elastic Plastic ◽  
Plastic Structure ◽  
Shakedown Limit

The paper discusses methods of evaluating the ratchet limit for an elastic/plastic structure subjected to cyclic thermal and mechanical loading. A recently developed minimization theorems by Ponter and Chen [2] provides a generalization of the shakedown limit theorems for histories of load in excess of shakedown. This allows the development of programming methods that locate the ratchet boundary in excess of shakedown. Examples of applications are provided including the performance of a cracked body subjected to cyclic thermal loading. Finally, the theory is used to discuss Kalnins’ [4] proposal that short cut finite element solutions may be used to assess whether a particular loading history lies within a ratchet limit.

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.

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.

An Analytical and Finite Element Analysis Study of Multilayered Pressure Vessels Under Thermal Conditions

2005 ◽  
Author(s):  
Soheir A. R. Naga ◽  
M. O. A. Mokhtar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wall Thickness ◽  
Thermal Loading ◽  
Thermal Conditions ◽  
Pressure Vessels ◽  
Element Analysis ◽  
Linear Temperature ◽  
Vessel Wall Thickness ◽  
Shell Geometry

The present paper is an endeavor towards assessing the stresses which may be induced in multi-layer pressure vessels subjected to the combined effects of pressure and temperature gradients across the vessel wall thickness. Assuming different geometries of membrane shells; namely cylindrical and spherical shells, a solution based on prescribed model with radial linear temperature distribution has been attained. The solution relates the induced stresses to the shell geometry, layers properties, number of layers, wall thickness and the working conditions of pressure and temperature gradient. In the analysis each layer composing the vessel thickness is treated as a membrane shell of revolution (thin lamina). By the aid of finite element analysis (FEA) technique, different cases of pressure vessels under thermal loading are investigated.

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.

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