Yield Surface and Complex Loading Path Simulation of a Duplex Stainless Steel Using a Bi-Phase Polycrystalline Model

2007 ◽  
Vol 567-568 ◽  
pp. 141-144 ◽  
Author(s):  
Pierre Evrard ◽  
Veronique Aubin ◽  
Suzanne Degallaix ◽  
Djimedo Kondo
Keyword(s):  
Stainless Steel ◽  
Uniaxial Tension ◽  
Compression Test ◽  
Plastic Anisotropy ◽  
Constant Strain Rate ◽  
Loading Path ◽  
Model Parameters ◽  
Proportional Loading ◽  
Loading Paths ◽  
Polycrystalline Model

In order to model the elasto-viscoplastic behaviour of an austenitic-ferritic stainless steel, the model initially developed by Cailletaud-Pilvin [1] [2] and used for modeling single-phase polycrystalline steel is extended in order to take into account the bi-phased character of a duplex steel. Two concentration laws and two local constitutive laws, based on the crystallographic slips and the dislocation densities, are thus simultaneously considered. The model parameters are identified by an inverse method. Simple tests among which tension test at constant strain rate and at different strain rates and uniaxial tension-compression test are used during the identification step. The predictive capabilities of the polycrystalline model are tested for non-proportional loading paths. It is shown that the model reproduces the over-hardening experimentally observed for this kind of loading paths. Then, yield surfaces are simulated during a uniaxial tension-compression test: it is shown that the distortion (i.e. plastic anisotropy induced by loading path) is correctly described.

scholarly journals Cyclic Deformation and Low-Cycle Fatigue for 316LN Stainless Steel under Non-proportional Loading

2019 ◽  
Vol 300 ◽  
pp. 08002
Author(s):  
Yajing Li ◽  
Bin Ren ◽  
Xu Chen
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Shear Strain ◽  
Strain Amplitude ◽  
Amplitude Ratio ◽  
Cyclic Behavior ◽  
Loading Path ◽  
Proportional Loading ◽  
Loading Paths ◽  
Shear Strain Amplitude

The effects of loading path and strain amplitude ratio on the cyclic behavior and fatigue life were investigated on a 316LN nuclear grade stainless steel employing a series of symmetrically strain-controlled fatigue tests at room temperature. The loading paths of Uniaxial, Torsional, Proportional, Rhombic, Rectangular, and Circular were employed with the constant equivalent strain amplitude of 0.5%. The strain amplitude ratio of 2.35, 1.73 and 1.27, defined by the ratio of shear strain amplitude to the axial strain amplitude, was realized by changing the shear strain amplitude under Proportional, Rhombic, Rectangular and Elliptical loading paths. As expected, the significant non-proportional additional hardening was observed. It’s interesting to note that the axial cyclic stress response varied with the strain amplitude ratio, and the law was different under different loading paths. The fatigue life of all the tests were evaluated by three critical plane criteria proposed by Smith-Watson-Topper (SWT), Fatemi-Socie (FS) and Chen-Xu-Huang (CXH). Results show that the SWT criterion significantly overestimated the fatigue life of non-proportional loading because the effect of shear damage was not considered. The CXH criterion for tensile-type failure yielded good prediction results except for two torsional data points. The FS criterion provided better predictions than other models.

Temperature-Dependence of Multiaxial Non-Proportional Cyclic Behavior of Type 316 Stainless Steel

1989 ◽  
Vol 111 (1) ◽  
pp. 32-39 ◽  
Author(s):  
S. Murakami ◽  
M. Kawai ◽  
K. Aoki ◽  
Y. Ohmi
Keyword(s):  
Stainless Steel ◽  
Temperature Dependence ◽  
Uniaxial Tension ◽  
Constant Strain Rate ◽  
Inelastic Strain ◽  
Cyclic Hardening ◽  
Material Behavior ◽  
Cyclic Behavior ◽  
316 Stainless Steel ◽  
Strain Paths

Temperature dependence of multiaxial cyclic behavior of type 316 stainless steel was elucidated experimentally. Cyclic tests under constant total-strain amplitudes were performed for uniaxial tension-compression and circular (non-proportional) strain paths at several temperatures; room temperature, 200°C, 400°C, 500°C, 600°C, and 700°C. The strain amplitudes of the cycles were specified to be 0.2, 0.3, and 0.4 percent under constant strain rate of 0.2 percent per min. A quantitative discussion was made with special emphasis on the difference between material behavior under uniaxial tension-compression strain cycles and multiaxial non-proportional circular ones at these temperatures. The most significant cyclic hardening was observed in the temperature range between 400°C and 600°C for both the proportional and the non-proportional strain cycles. At these particular temperatures, much larger inelastic strain was accumulated until a cyclic stabilization was obtained. Though the effect of non-proportionality in the cyclic strain paths on the cyclic hardening was significant particularly at the temperature below 450°C, it rapdily decreased at higher temperatures.

Effect of Process Parameters on Hydroforming of Stainless Steel Tubular Components with Rectangular Section

2013 ◽  
Vol 749 ◽  
pp. 67-74 ◽  
Author(s):  
Yong Xu ◽  
Shi Hong Zhang ◽  
Qing Xun Zhu ◽  
Ming Cheng ◽  
Hong Wu Song ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Process Parameters ◽  
304 Stainless Steel ◽  
Loading Path ◽  
Rectangular Section ◽  
Loading Paths ◽  
Tubular Components

The effects of key process parameters including initial lengths of tube blank, forming velocity and loading paths on hydroformability of stainless steel tubular components with rectangular section were systematically investigated. The results showed that sufficient axial feed must be given before the tube contacting the surface of die in order to prevent the excessive thickness thinning, especially for longer tube blank. The lower loading velocity led to enhanced formability. It is more important that pulsating loading path observably improved the formability of 304 stainless steel.

The Effects of Nonproportional Loading on the Elastic-Plastic Crack-Tip Fields

2016 ◽  
Vol 853 ◽  
pp. 83-87 ◽  
Author(s):  
Zhao Yu Jin ◽  
Xin Wang ◽  
Dun Ji Yu ◽  
Xu Chen
Keyword(s):  
Stress Field ◽  
Outer Boundary ◽  
Crack Tip ◽  
Loading Path ◽  
Small Scale ◽  
Proportional Loading ◽  
Nonproportional Loading ◽  
Elastic Plastic ◽  
Loading Paths ◽  
Crack Tip Constraint

In this paper, the loading path effects on the plane strain elastic-plastic crack-tip stress field are investigated computationally. Three different loading sequences include one proportional loading and two non-proportional loading paths are applied to the modified boundary layer (MBL) model under small-scale yielding conditions. For the same external displacement field applied at the outer boundary of the MBL model, the mode I K field and T-stress field combined as the different loading paths are applied to investigate the influence of the nonproportional loading. The results show that for either the compressive or tensional T-stress, the loading path which applied K field followed by T field generates the lower crack-tip constraint. There is only slightly difference between the proportional loading path and that with the T-stress field following by K field. The results show that it is very important to include the load sequence effects in fracture analysis when dealing with nonproportional loading conditions.

Multiaxial Time-Dependent Cyclic Deformation of Stainless Steel at High Temperatures

2006 ◽  
Author(s):  
Qing Gao ◽  
Zhi Shi ◽  
Guozheng Kang ◽  
Yujie Liu
Keyword(s):  
Stainless Steel ◽  
Time Dependence ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Time Dependent ◽  
Nuclear Engineering ◽  
Proportional Loading ◽  
Loading Rates ◽  
Loading Paths ◽  
Cyclic Straining

The multiaxial time-dependent cyclic deformation behavior of stainless steel (i.e., 1Cr18Ni9) was studied experimentally at 250 °C and 700 °C. In the tests, the strain cyclic characteristics and ratcheting behavior of the material were observed under multiaxial cyclic straining/stressing at different loading rates and with various hold-times and non-proportional loading paths. The results show that the cyclic deformation behavior of the material is significantly influenced by the non-proportional loading paths and present apparent time dependence, especially at 700°C. Some significant conclusions useful for the design and assessment of pipe structures in nuclear engineering are obtained.

Forming Limit of Sheet Metal Based on Different Property Imperfection

2010 ◽  
Vol 146-147 ◽  
pp. 1206-1210
Author(s):  
Yu Yan ◽  
Hai Bo Wang
Keyword(s):  
Uniaxial Tension ◽  
Sheet Metal ◽  
Yield Criterion ◽  
Tension Test ◽  
Loading Path ◽  
Forming Limit ◽  
Proportional Loading ◽  
Material Parameters ◽  
Instability Theory ◽  
Similarities And Differences

From more than one uniaxial tension test curve, it can be found that mechanics property of sheet metal is inhomogeneous. Based on this truth, a new method for prediction of forming limit of sheet metal is proposed. Using this method, theoretical FLDs are obtained under proportional loading path based on Hill48 yield criterion. The effects of several material parameters on forming limit are obtained. Similarities and differences between this method and M-K instability theory are analyzed and some advices on the application of this method are given.

On the full coupling of plastic anisotropy and anisotropic ductile damage under finite strains

2016 ◽  
Vol 26 (7) ◽  
pp. 1080-1123 ◽  
Author(s):  
Houssem Badreddine ◽  
Khemais Saanouni
Keyword(s):  
Constitutive Equations ◽  
Plastic Anisotropy ◽  
Complex Loading ◽  
Finite Strains ◽  
Ductile Damage ◽  
Rotating Frame ◽  
Proportional Loading ◽  
Strongly Coupled ◽  
Loading Paths ◽  
Model Response

In this work, thermodynamically consistent, non-associative and fully anisotropic elastoplastic constitutive equations strongly coupled with ductile anisotropic damage developed in previous work are used to study the responses of the proposed model under various simple and complex loading paths. First, the complete set of the fully coupled non-associative constitutive equations based on the rotated frame formulation (RFF) for finite strains is summarized and shortly discussed. Then, the effect of the rotating frame in the model response is analyzed on the light of typical loading paths. The influence of the induced plastic anisotropies on the evolution of the anisotropic ductile damage is investigated. Finally, the responses of the model for non-proportional loading paths are studied, compared and discussed with respect to the initial and induced anisotropies of the plastic flow and the ductile damage evolution as well as with respect to the rotating frame choice.

Comparative Study of the Additional Hardening Effects of Three Structural Steels

2006 ◽  
Vol 514-516 ◽  
pp. 534-538
Author(s):  
Luís G. Reis ◽  
Bin Li ◽  
Manuel de Freitas
Keyword(s):  
Low Cycle Fatigue ◽  
Testing Machine ◽  
Great Influence ◽  
Structural Steels ◽  
Loading Path ◽  
Multiaxial Loading ◽  
Cycle Fatigue ◽  
Proportional Loading ◽  
Loading Paths ◽  
Additional Hardening

For a safe and reliable design of components, it is needed to study the effects of multiaxial loading and particularly the non-proportional loadings on the fatigue damage. The objective of this paper is to evaluate and compare the additional hardening effects of proportional and non-proportional loading paths. Low-cycle fatigue behaviour of three structural steels: CK45 (ferritic-perlitic microstructure) normalized steel, 42CrMo4 (bainitic microstructure) quenched and tempered steel and stainless steel (austenitic microstructure) X10CrNiS 18 9 are studied under different proportional and non-proportional loading paths and different levels. A series of tests of biaxial low-cycle fatigue composed of tension/compression with static or cyclic torsion were carried out on a biaxial servo-hydraulic testing machine Instron 8088. The experiments showed that the three materials studied have very different additional hardening behaviour, under multiaxial cyclic loading paths. The local cyclic stress/strain states are influenced by the multiaxial loading paths due to interactions between the normal stress and shear stress during cyclic plastic deformation. The microstructure is an important key and has a great influence on the additional hardening. The additional hardening effect is dependent of the loading path and also the intensity of the loading.

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