Characteristics of the Static and Dynamic Behavior of Steel Piles with a Welded Joint

2008 ◽  
Vol 580-582 ◽  
pp. 613-616
Author(s):  
Gab Chul Jang ◽  
Kyong Ho Chang
Keyword(s):  
Residual Stress ◽  
Dynamic Behavior ◽  
Dynamic Loading ◽  
Welded Joint ◽  
Three Dimensional ◽  
Steel Structures ◽  
Plasticity Model ◽  
Dependent Plasticity ◽  
Rate Dependent ◽  
Steel Piles

During welding process to make joints, residual stress is inevitably produced and weld metal should be used. These influence the static and dynamic behavior of steel structures with welded joints, such as steel piles. In steel structures, dynamic mechanical behavior is different to static mechanical behavior. Therefore, to accurately predict the behavior of steel piles with a welded joint under static-dynamic loading, the research on influence of a welded joint on the static and dynamic behavior of steel piles is necessary. For that purpose, a rate-dependent plasticity model was used, considering strain rate hardening and temperature rise. In this paper, the distribution of welding residual stress in a welded joint was computed by using three-dimensional heat conduction analysis and three-dimensional thermal elastic-plastic analysis. The behavior of steel piles with a welded joint under axial static and dynamic loading was investigated by using three-dimensional elastic-plastic finite element analysis, which employed a rate-dependent plasticity model and included residual stress and mechanical properties of weld metal in a welded joint. The rate-dependent plasticity model used in this paper is proposed by the authors based on the static-dynamic loading tests. Numerical analysis results of steel piles with a welded joint were compared to those without a welded joint. In comparison, the characteristics of static and dynamic behavior of steel piles with a welded joint were investigated.

Influence of the Welded Joint on the Mechanical Behavior of Steel Piles during Static and Dynamic Deformation

2007 ◽  
Vol 345-346 ◽  
pp. 1469-1472
Author(s):  
Gab Chul Jang ◽  
Kyong Ho Chang ◽  
Chin Hyung Lee
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Mechanical Behavior ◽  
Welded Joint ◽  
Dynamic Deformation ◽  
Three Dimensional ◽  
Steel Structures ◽  
Residual Stress Distribution ◽  
Dynamic Mechanical Behavior ◽  
Steel Piles

During manufacturing the welded joint of steel structures, residual stress is produced and weld metal is used inevitably. And residual stress and weld metal influence on the static and dynamic mechanical behavior of steel structures. Therefore, to predict the mechanical behavior of steel pile with a welded joint during static and dynamic deformation, the research on the influence of the welded joints on the static and dynamic behavior of steel pile is clarified. In this paper, the residual stress distribution in a welded joint of steel piles was investigated by using three-dimensional welding analysis. The static and dynamic mechanical behavior of steel piles with a welded joint is investigated by three-dimensional elastic-plastic finite element analysis using a proposed dynamic hysteresis model. Numerical analyses of the steel pile with a welded joint were compared to that without a welded joint with respect to load carrying capacity and residual stress distribution. The influence of the welded joint on the mechanical behavior of steel piles during static and dynamic deformation was clarified by comparing analytical results

Bifurcation Analyses of Steel and Concrete with Rate-Dependent Properties Part One: Model Formulation and Verification

2002 ◽  
Vol 4 (4) ◽  
pp. 217-224
Author(s):  
Yuxing Liu ◽  
Luming Shen ◽  
Zhen Chen
Keyword(s):  
Damage Model ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Environmental Engineering ◽  
Material Failure ◽  
Plasticity Model ◽  
Model Formulation ◽  
University Of Missouri ◽  
Rate Dependent ◽  
Elasto Plasticity

Department of Civil and Environmental Engineering, University of Missouri-Columbia, Columbia MO 65211–2200, U.S.A. The effects of strain rate on the mechanical properties of carbon steel and plain concrete are investigated through a rate-dependent elasto-plasticity model and rate-dependent elasto-damage model, respectively. Continuum tangent stiffness tensors are derived for both models so that bifurcation analyses can be performed to identify the onset of material failure. Three-dimensional constitutive model solvers are designed and the numerical results are compared with the experimental data to verify the proposed models.

New Measuring Method of Three-Dimensional Residual Stresses in Long Welded Joints Using Inherent Strains as Parameters—Lz Method

1989 ◽  
Vol 111 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Yukio Ueda ◽  
Keiji Fukuda
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Welded Joint ◽  
Present Report ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Measuring Method ◽  
Residual Stress Distribution ◽  
Two Dimensional ◽  
Special Case

In this paper, a new measuring method of three-dimensional residual stresses induced in a butt welded joint is presented. The proposed method is based on a general approach developed by the authors, in which inherent strains (the source of residual stresses) are dealt with as parameters. In the present report, three-dimensional residual stresses in a long body, in which the residual stress distribution is uniform in longitudinal direction, is considered as a special case. It is shown that the measurement of the three-dimensional residual stress, in this case, can be reduced to a combination of two sets of measurements of two-dimensional residual stresses. This method is applied to determine the residual stresses in an actual welded joint and its reliability and practicability are also demonstrated.

Inherent-Strain-Based Theory of Measurement of Three-Dimensional Residual Stress Distribution and Its Application to a Welded Joint in a Reactor Vessel

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Keiji Nakacho ◽  
Naoki Ogawa ◽  
Takahiro Ohta ◽  
Michisuke Nayama
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Strain Distribution ◽  
Measurement Method ◽  
Welded Joint ◽  
Three Dimensional ◽  
Reactor Vessel ◽  
Residual Stress Distribution ◽  
Stress Distributions ◽  
Inherent Strain

The stress that exists in a body under no external force is called the inherent stress. The strain that is the cause (source) of this stress is called the inherent strain. This study proposes a general theory of an inherent-strain-based measurement method for the residual stress distributions in arbitrary three-dimensional bodies and applies the method to measure the welding residual stress distribution of a welded joint in a reactor vessel. The inherent-strain-based method is based on the inherent strain and the finite element method. It uses part of the released strains and solves an inverse problem by a least squares method. Thus, the method gives the most probable value and deviation of the residual stress. First, the basic theory is explained in detail, and then a concrete measurement method for a welded joint in a reactor vessel is developed. In the method, the inherent strains are unknowns. In this study, the inherent strain distribution was expressed with an appropriate function, significantly decreasing the number of unknowns. Five types of inherent strain distribution functions were applied to estimate the residual stress distribution of the joint. The applicability of each function was evaluated. The accuracy and reliability of the analyzed results were assessed in terms of the residuals, the unbiased estimate of the error variance, and the welding mechanics. The most suitable function, which yields the most reliable result, was identified. The most reliable residual stress distributions of the joint are shown, indicating the characteristics of distributions with especially large tensile stress that may produce a crack.

Effect of Residual Stress and Weld Metal on Hysteretic Behavior of a Welded Tubular T-Joint

2007 ◽  
Vol 353-358 ◽  
pp. 2077-2080
Author(s):  
Gab Chul Jang ◽  
Kyong Ho Chang ◽  
Chin Hyung Lee
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Weld Metal ◽  
Welded Joints ◽  
Three Dimensional ◽  
Welding Process ◽  
Hysteretic Behavior ◽  
Cyclic Plasticity ◽  
Plasticity Model ◽  
Cyclic Plasticity Model

During the welding process to make welded joints, residual stress is inevitably generated and weld metal is used. Welding Residual stress is influenced on the behavior of welded joints under monotonic and cyclic loading. And the weld metals used in welding process have different mechanical characteristics than structural steels. Therefore, to accurately predict the hysteretic behavior of welded joints, the effect of residual stress and weld metal must be investigated. In this paper, the residual stress distribution in a welded tubular T-joint was investigated by carrying out three-dimensional non-steady heat conduction analysis and three-dimensional thermal elastic-plastic analysis. To consider a effect of base metal(SM490) and weld metal(E71T-1), a cyclic plasticity model was formulated based on monotonic and cyclic loading tests. And the formulated model was applied to three-dimensional elastic-plastic finite element analysis. The effect of residual stress and weld metal on hysteretic behavior of a welded tubular T-joint was investigated by carrying out numerical analyses considering residual stress and cyclic plasticity model of base metal and weld metal respectively.

Residual Stress Analysis by Simplified Inherent Strain at Welded Pipe Junctures in a Pressure Vessel

1999 ◽  
Vol 121 (4) ◽  
pp. 353-357 ◽  
Author(s):  
M. Mochizuki ◽  
M. Hayashi ◽  
T. Hattori
Keyword(s):  
Residual Stress ◽  
Pressure Vessel ◽  
Welded Joint ◽  
Three Dimensional ◽  
Small Diameter ◽  
Welding Residual Stress ◽  
The Finite Element Method ◽  
Diameter Pipe ◽  
Welded Pipe ◽  
Inherent Strain

We present a new and simplified method of estimating residual stress in welded structures by using inherent strain. The method makes use of elastic analysis by means of the finite element method and is used to calculate the residual stress in complicated three-dimensional structures efficiently. The inherent strain distribution in a welded joint of a small-diameter pipe penetrating a pressure vessel was assumed to be a simple distribution, and the residual stress was calculated. Inherent strain distributions were inferred from those of welded joints with simple shapes. The estimated residual stress using these inferred inherent strains agrees well with the measurements of a mock-up specimen. The proposed method is a simple way to estimate welding residual stress in three-dimensional structures of complicated shapes.

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