Numerical Simulation of Residual Stresses Due to Cladding Process

2007 ◽  
Author(s):  
Dieter Siegele ◽  
Marcus Brand
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Residual Stresses ◽  
Base Metal ◽  
Base Material ◽  
Pressure Vessels ◽  
Measured Temperature ◽  
Residual Stress Field

The inner surface of reactor pressure vessels is protected against corrosion by an austenitic cladding. Generally, the cladding is welded on the ferritic base metal with two layers to avoid sub-clad cracks and to improve the microstructure of the cladding material. On the other hand, due to the cladding process and the difference of the thermal expansion coefficient of the austenitic cladding and the ferritic base material residual stresses act in the component. This residual stress field is important for assessing crack postulates in the cladding or subclad flaws in the base metal. For the determination of the residual stress field, plates of RPV steel were cladded and heat treated representative to the RPV relevant conditions. During the cladding process the temperature and distortion were measured as basis for the validation of the finite element simulations. The numerical simulation was performed with the finite element code SYSWELD. The heat source of the model was calibrated on the measured temperature profile. In the analysis, the temperature dependent material properties as well as the transformation behavior of the ferritic base metal were taken into account. The calculated residual stresses show tensile stresses in the cladding followed by compressive stresses in the base metal that are in agreement with measurements with X-ray diffraction technique.

Numerical Calculation of Residual Stress Corrected J-Integral Using ABAQUS

2014 ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Residual Stresses ◽  
Stress Effect ◽  
J Integral ◽  
Residual Stress Field ◽  
Path Independence ◽  
Residual Stress Effect ◽  
Senb Specimen

Residual stresses exist in welded structures due to thermal stresses. Without temperature change, large plastic deformation can result in “cold” residual stresses in a wrinkle or dent in a metallic pipe. For a crack in residual stress field, residual stresses might have strong effect on fracture parameter, the J-integral. In order to ensure its path-independence, different correction methods have been developed in consideration of residual stress effect. Recently, the finite element commercial software ABAQUS adopted one of the correction methods, and is able to calculate the residual stress corrected J-integral. A brief review is first given to the J-integral definition, the conditions of path-independence or path-dependence, and the modifications to consider the residual stress effect. A modified single edge-notched bend (SENB) specimen is then used, and a numerical procedure is developed for ABAQUS to evaluate the path-independence of the residual stress corrected J-integral. Detailed elastic-plastic finite element analyses are performed for the SENB specimen in three-point bending. The residual stress field, crack-tip stress field, and J-integral with and without consideration of residual stresses are discussed.

Assessment of the Crack Compliance Method and the Introduction of Residual Stresses by Shot Peening Using the Finite Element Method

2009 ◽  
Vol 15 ◽  
pp. 109-114 ◽  
Author(s):  
G. Urriolagoitia-Sosa ◽  
E. Zaldivar-González ◽  
J.M. Sandoval Pineda ◽  
J. García-Lira
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Shot Peening ◽  
Working Life ◽  
The Finite Element Method ◽  
Residual Stress Field ◽  
Main Effect

The interest on the application of the shot peening process to arrest and/or delay crack growth is rising. The main effect of the shot peening technique is to introduce a residual stress field that increases the working life of mechanical components. In this paper, it is presented the numerical simulation (FEM) of the shot peening process and the effect of introducing a residual stress field. Besides, the consequence of changing the sizes of the impacting ball is analyzed. This work also used the Crack Compliance Method (CCM) for the determination of residual stresses in beams subjected to a numerical simulation of a shot peening process. The numerical results obtained provide a quantitative demonstration of the effect of shot peening on the introduction of residual stresses by using different sizes of impacting balls and assess the efficiency of the CCM.

scholarly journals Evaluation of the Impact of Residual Stresses in Crack Initiation with the Application of the Crack Compliance Method Part I, Numerical Analysis

2010 ◽  
Vol 24-25 ◽  
pp. 253-259 ◽  
Author(s):  
G. Urriolagoitia-Sosa ◽  
B. Romero-Ángeles ◽  
Luis Héctor Hernández-Gómez ◽  
G. Urriolagoitia-Calderón ◽  
Juan Alfonso Beltrán-Fernández ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Numerical Analysis ◽  
Stress Field ◽  
Crack Initiation ◽  
Residual Stresses ◽  
Main Concern ◽  
Residual Stress Field ◽  
Set Up ◽  
The Impact

The understanding of how materials fail is still today a fundamental research problem for scientist and engineers. The main concern is the assessment of the necessary conditions to propagate a crack that will eventually lead to failure. Nevertheless, this kind of analysis tends to be more complicated, when a prior history in the material is taken into consideration and it will be extremely important to recognize all the factors involved in this process. In this work, a numerical simulation of the introduction of residual stresses, which change the crack initiation conditions, in a modified compact tensile specimen to change the condition of crack initiation is presented. Four numerical analyses were carried out; an initial evaluation was performed in a specimen without a crack and it was used for the estimation of a residual stress field produced by an overload; three more cases were simulated and a crack was introduced in each specimen (1 mm, 5 mm and 10 mm, respectively). The overload was then applied to set up a residual stress field into the component; furthermore, in each case the crack compliance method (CCM) was applied to measure the induced residual stress field. By performing this numerical simulation, the accuracy of the crack compliance method can be evaluated. On the other hand, elastic-plastic finite element analysis was utilized for the residual stress estimation. The numerical analysis was based on the mechanical properties of a biocompatible material (AISI 316L). The obtained results provided significant data about diverse factors, like; the manner in which a residual stress field could modify the crack initiation conditions, the convenient set up for induction of a beneficial residual stresses field, as well as useful information that can be applied for the experimental implementation of this research.

Numerical Analyses of Residual Stress Fields in Welded Components

2009 ◽  
Author(s):  
Dieter Siegele ◽  
Marcus Brand ◽  
Igor Varfolomeev ◽  
Jo¨rg Hohe
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Base Metal ◽  
Stress Fields ◽  
X Ray Diffraction ◽  
Residual Stress Field ◽  
Temperature Dependent ◽  
Compressive Stresses ◽  
Core Shroud

Residual stresses in welded components can influence the lifetime significantly. Besides experimental methods of residual stress measurements numerical methods of welding simulation are an important tool to determine the whole residual stress field in a component as a basis for lifetime prediction. As examples, the residual stresses in a core shroud of a boiling water reactor (BWR) and in a cladded plate have been investigated. In case of the core shroud postulated cracks in the residual stress field of the weld have been assessed with respect to possible crack corrosion cracking. For the cladded plate, the numerical simulation of the cladding and heat treatment process was accompanied by measurements of temperature, distortions and residual stresses. In the analysis, the temperature dependent material properties as well as the transformation behavior of the ferritic base metal were taken into account. The calculated residual stresses show tensile stresses in the cladding followed by compressive stresses in the base metal that are in agreement with measurements with X-ray diffraction technique.

Characterising Residual Stresses in Rectangular Beam Specimens Following Thermo-Mechanical Loading

2006 ◽  
Author(s):  
Ali Mirzaee-Sisan ◽  
Christopher E. Truman ◽  
David J. Smith
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Stress Field ◽  
Residual Stresses ◽  
Mechanical Loading ◽  
Ferritic Steel ◽  
Thermal Stresses ◽  
Residual Stress Field ◽  
Rectangular Beam

The neutron diffraction (ND) technique was used to characterise residual stress fields in thin rectangular beam specimens containing residual stresses induced thermo-mechanically by partial quenching. Two types of material were considered, type 316H stainless steel and A533B ferritic steel. The work was motivated by a need to investigate the influence of residual stress on the fracture behaviour of steels. During quenching, specimens experienced a severe temperature gradient which induced thermal stresses resulting in plastic strains and a subsequent residual stress field. An extensive finite element (FE) analysis was undertaken to predict the residual stress following thermo-mechanical loading. It was shown that partial quenching generated a considerable residual stress field in 316H stainless steel. However, the level of residual stresses in the A533B steel specimens was lower than that 316H stainless steel specimens. There was acceptable agreement between the finite element simulations and measurements with simulations generally predicting higher tensile residual stresses following partial quenching than those measured in the 316H stainless steel, and lower tensile residual stresses than those measured in the A533B ferritic steel.

Multipass low-plasticity burnishing induced residual stresses: Three-dimensional elastic-plastic finite element modelling

2004 ◽  
Vol 218 (6) ◽  
pp. 663-668 ◽  
Author(s):  
W Zhuang ◽  
B Wicks
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Residual Stresses ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Residual Stress Field ◽  
Moving Contact ◽  
Low Plasticity Burnishing

Low-plasticity burnishing (LPB) is a surface modification process involving complex cyclic plastic deformation that results in the development of a deep residual stress field. In order to achieve an optimal LPB-induced residual stress field for the geometry appropriate to the aircraft engine component, the key parameters of the LPB process, such as burnishing load, burnishing ball size and material properties, need to be determined. For this purpose, a three-dimensional non-linear moving contact finite element model is proposed to simulate the multipass LPB process and to predict the effects of those parameters on the resultant residual stress field. The material constitutive model used in the finite element analysis has been developed from the cyclic stress/strain response obtained from experimental measurements on the material. Prediction of the LPB-induced residual stresses by the finite element model appears to agree reasonably well with X-ray diffraction measurements.

Numerical and experimental investigations of effects of residual stresses on crack behavior in Aluminum 6082-T6

2012 ◽  
Vol 226 (9) ◽  
pp. 2178-2191 ◽  
Author(s):  
Mohammadreza Farahani ◽  
Iradj Sattari-Far ◽  
Davood Akbari ◽  
Rene Alderliesten
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Residual Stresses ◽  
Crack Growth ◽  
Crack Tip ◽  
Residual Stress Field ◽  
Integrity Assessment ◽  
Crack Tip Constraint

In the structural integrity assessment, residual stresses play an important role. The residual stresses affect both the crack driving forces and the crack-tip constraint. To investigate the interaction of residual stresses with mechanical loading during the onset of crack growth in Aluminum 6082-T6, modified single edge-notched bending specimens were used. Aluminum 6082 has the highest strength of the 6000 series alloys with excellent corrosion resistance. A residual stress field was created in the specimens by pre-loading. To accurately quantify the residual stress field created during this test procedure, the strains were measured during loading and unloading and compared with finite element results. After the introduction of the residual stress field, the specimens were tested under three-point bending to determine the load versus displacement behavior and fracture toughness. Also, a post-processor for finite element calculation was developed to enable determination of the J-integral values for the specimens having residual stresses. The constraint parameters Q and R were calculated at the crack-tip to describe the stress field in this region. The parameter Q is used to characterize the loading and geometry constraint, and the parameter R is used for characterizing the crack-tip constraint due to residual stresses. It is observed that tensile residual stresses around the crack-tip increase the crack-tip constraint and decrease the fracture toughness of the bodies. By increasing the external load, the constraint parameter R goes toward zero and the effects of residual stresses on the crack growth resistance become negligible.

Finite Element Validation of the over-Coring Deep-Hole Drilling Technique

2011 ◽  
Vol 70 ◽  
pp. 291-296 ◽  
Author(s):  
Sayeed Hossain ◽  
Ed J. Kingston ◽  
Christopher E. Truman ◽  
David John Smith
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Residual Stress Measurement ◽  
Hole Drilling ◽  
Deep Hole ◽  
Residual Stress Field ◽  
Deep Hole Drilling

The main objective of the present study is to validate a simple over-coring deep-hole drilling (oDHD) residual stress measurement technique by utilising finite element simulations of the technique. A number of three dimensional (3D) finite element analyses (FEA) were carried out to explore the influence of material removal and the cutting sequence during the deep-hole drilling (DHD) residual stress measurement process on the initial residual stress field. Two models were considered in the study. First, the residual stress field predicted in a rapid spray water quenched solid cylinder was used as the initial stress field for the DHD FE model. The DHD reconstructed residual stresses were compared with the initial FE predicted stresses. Different cutting sequences and different dimensions were systematically simulated before arriving at an optimum solution for the oDHD technique. The oDHD technique significantly improved the spatial resolution and was applied in a second model consisting of a 40mm thick butt-welded pipe. The DHD reconstructed residual stresses compared very well with the initial FE predicted weld residual stress thereby validating the oDHD technique.

scholarly journals Residual stresses in thermite welded rails: significance of additional forging

2020 ◽  
Vol 64 (7) ◽  
pp. 1195-1212
Author(s):  
B. Lennart Josefson ◽  
R. Bisschop ◽  
M. Messaadi ◽  
J. Hantusch
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welding Process ◽  
Surface Zone ◽  
Fe Model ◽  
Uneven Surface ◽  
Residual Stress Field ◽  
High Dynamic

Abstract The aluminothermic welding (ATW) process is the most commonly used welding process for welding rails (track) in the field. The large amount of weld metal added in the ATW process may result in a wide uneven surface zone on the rail head, which may, in rare cases, lead to irregularities in wear and plastic deformation due to high dynamic wheel-rail forces as wheels pass. The present paper studies the introduction of additional forging to the ATW process, intended to reduce the width of the zone affected by the heat input, while not creating a more detrimental residual stress field. Simulations using a novel thermo-mechanical FE model of the ATW process show that addition of a forging pressure leads to a somewhat smaller width of the zone affected by heat. This is also found in a metallurgical examination, showing that this zone (weld metal and heat-affected zone) is fully pearlitic. Only marginal differences are found in the residual stress field when additional forging is applied. In both cases, large tensile residual stresses are found in the rail web at the weld. Additional forging may increase the risk of hot cracking due to an increase in plastic strains within the welded area.

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