Modeling the Deformation Response of High Strength Steel Pipelines—Part I: Material Characterization to Model the Plastic Anisotropy

2012 ◽  
Vol 79 (5) ◽  
Author(s):  
Sunil Neupane ◽  
Samer Adeeb ◽  
Roger Cheng ◽  
James Ferguson ◽  
Michael Martens

The design equations for pipelines subjected to both internal pressure and longitudinal loading are based on the isotropic hardening plasticity model. However, high strength steel (HSS) pipelines exhibit plastic anisotropy, which cannot be incorporated in the traditional isotropic hardening plasticity model. The stress strain behaviors of HSS in the longitudinal and the circumferential directions are different. Thus, it would not be desirable to adopt the same design equations based on the isotropic hardening plasticity model for HSS pipelines. The design equations of HSS steel pipelines have to be developed by solving numerical models incorporating a suitable material plasticity constitutive model for the HSS that can deal with the exhibited plastic anisotropy. In this paper, various plasticity models are studied and an appropriate plasticity model is adopted and calibrated to model the plastic anisotropy exhibited by the HSS.

2012 ◽  
Vol 79 (5) ◽  
Author(s):  
Sunil Neupane ◽  
Samer Adeeb ◽  
Roger Cheng ◽  
James Ferguson ◽  
Michael Martens

The material model proposed in Part I (Neupane et al., 2012, “Modeling the Deformation Response of High Strength Steel Pipelines—Part I: Material Characterization to Model the Plastic Anisotropy,” ASME J. Appl. Mech., 79, p. 051002) is used to study the deformation response of high strength steel. The response of pipes subjected to frost upheaval at a particular point is studied using an assembly of pipe elements, while buckling of pipes is examined using shell elements. The deformation response is obtained using two different material models. The two different material models used were the isotropic hardening material model and the combined kinematic hardening material model. Two sets of material stress-strain data were used for the isotropic hardening material model; data obtained from the longitudinal direction tests and data obtained from the circumferential direction tests. The combined kinematic hardening material model was calibrated to provide an accurate prediction of the stress-strain behavior in both the longitudinal direction and the circumferential direction. The deformation response of a pipe model using the three different material data sets was studied. The sensitivity of the response of pipelines to the choice of a material model and the material data set is studied for the frost upheaval and local buckling.


2011 ◽  
Vol 410 ◽  
pp. 232-235 ◽  
Author(s):  
Sansot Panich ◽  
Vitoon Uthaisangsuk ◽  
Surasak Suranuntchai ◽  
Suwat Jirathearanat

Anisotropic plastic behavior of advanced high strength steel sheet of grade TRIP780 (Transformation Induced Plasticity) was investigated using three different yield functions, namely, the von Mises’s isotropic, Hill’s anisotropic (Hill’48), and Barlat’s anisotropic (Yld2000-2d) criterion. Uniaxial tensile and balanced biaxial test were conducted for the examined steel in order to characterize flow behavior and plastic anisotropy for different stress states. Especially, disk compression test was performed for obtaining balanced r-value. All these data were used to determine the anisotropic coefficients. As a result, yield stresses and r-values for different directions were calculated according to these yield criteria. The results were compared with experimental data. To verify the modelling accuracy, tensile tests of various notched samples were carried out and stress-strain distributions in the critical area were characterized. By this manner, the effect of stress triaxiality due to different notched shapes on the strain localization calculated by the investigated yield criteria could be studied.


2010 ◽  
Vol 97-101 ◽  
pp. 200-203 ◽  
Author(s):  
Ke Chen ◽  
Jian Ping Lin ◽  
Mao Kang Lv ◽  
Li Ying Wang

With the increasing use of finite element analysis method in sheet forming simulations, springback predictions of advanced high strength steel (AHSS) sheet are still far from satisfactory precision. The main purpose of this paper was to provide a method for accurate springback prediction of AHSS sheet. Material model with Hill’48 anisotropic yield criterion and nonlinear isotropic/kinematic hardening rule were applied to take account the anisotropic yield behavior and the Bauschinger effect during forming processes. U-channel forming and springback simulation was performed using ABAQUS software. High strength DP600 sheet was investigated in this work. The simulation results obtained with the proposed material model agree well with the experimental results, which show a remarkable improvement of springback prediction compared with the commonly used isotropic hardening model.


Author(s):  
Wei Tong

An accurate description of the directional dependence of uniaxial tensile yielding and plastic flow in advanced high-strength steel sheets may require either a nonassociated plasticity model with separate quadratic yield function and flow potential or an associated plasticity model with nonquadratic yield function. In this paper, Gotoh's fourth-order homogeneous polynomial yield function is applied to model two advanced high-strength steel sheets in an associated plasticity model. Both the parameter selection for calibrating Gotoh's yield function and its positivity and convexity verification are given in some detail. Similarities and differences between the associated plasticity model presented here and the nonassociated one appeared in the literature are discussed in terms of the directional dependence of yield stresses and plastic strain ratios under uniaxial tension and yield stresses under biaxial tension loading.


2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879743 ◽  
Author(s):  
Van-Canh Tong ◽  
Duc-Toan Nguyen

In this article, a numerical model for predicting spring-back in U-draw bending of DP350 high-strength steel sheet was presented. First, the hardening models were formulated based on combined isotropic–kinematic hardening laws, along with the traditional pure isotropic and kinematic hardening laws. A simplified method was proposed for determining the material parameters. Comparison of stress–strain curves of uniaxial tests at various pre-strains predicted by the numerical models and experiment showed that the combined isotropic–kinematic hardening model could accurately describe the Bauschinger effect and transient behavior subjected to cyclic loading conditions. Then, a finite element model was created to simulate the U-draw bending process using ABAQUS. Simulations were then conducted to predict the spring-back of DP350 high-strength steel in U-draw bending with geometry provided in the NUMISHEET’2011 benchmark problems. It was shown that the predictions of spring-back using the proposed model were in good agreement with the experimental results available in the literature. Finally, the effects of various tool and process parameters such as punch profile radius, die profile radius, blank holding force, and punch-to-die clearance on the spring-back were investigated. The simulation results suggested the significance of tool and process parameters on the final shape of the formed parts influenced by the spring-back.


2016 ◽  
Vol 89 ◽  
pp. 205-214 ◽  
Author(s):  
Eeva Mikkola ◽  
Gary Marquis ◽  
Pauli Lehto ◽  
Heikki Remes ◽  
Hannu Hänninen

Sign in / Sign up

Export Citation Format

Share Document