scholarly journals Triaxial behavior of granular material under complex loading path by a new numerical true triaxial engine

2019 ◽  
Vol 30 (4) ◽  
pp. 700-706 ◽  
Author(s):  
Xiaoliang Wang ◽  
Zhen Zhang ◽  
Jiachun Li
Keyword(s):  
Granular Material ◽  
Complex Loading ◽  
Loading Path ◽  
True Triaxial

Comparison of two transformation plasticity models, with and without kinematic hardening for bainitic transformation under non-proportional loading path

2004 ◽  
Vol 120 ◽  
pp. 177-183
Author(s):  
M. Coret ◽  
A. Combescure
Keyword(s):  
Biaxial Loading ◽  
Kinematic Hardening ◽  
Complex Loading ◽  
Bainitic Transformation ◽  
Loading Path ◽  
Experimental Setup ◽  
Plasticity Model ◽  
Transformation Plasticity ◽  
Proportional Loading

This article deals with the multiphasic, anisothermal behaviour of 16MND5 steel under complex loading. We are focusing more specifically on the modelization of transformation plasticity induced by proportional or nonproportional biaxial loading during the bainitic transformation. A first part recalls Leblond's transformation plasticity model with or without hardening. We also describe the experimental setup used to get transformation plasticity tests under tension-torsion loadings. The last part deals with the TrIP models (with or without hardening) identification and their use for the nonproportional tests simulation.

Crack Growth Orientation in Two Structural Materials under Multiaxial Fatigue Loading

2008 ◽  
Vol 587-588 ◽  
pp. 892-897
Author(s):  
Luís G. Reis ◽  
Bin Li ◽  
Manuel de Freitas
Keyword(s):  
Testing Machine ◽  
Experimental Studies ◽  
Complex Loading ◽  
Fatigue Loading ◽  
Structural Materials ◽  
Optical Microscope ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Loading Path ◽  
Biaxial Testing

In real engineering components and structures, many accidental failures are due to unexpected or additional loadings, such as additional bending or torsion, etc. Therefore, it has attracted more research attentions to study the mechanical behavior of materials under complex loading conditions. Two typical structural materials are studied and compared in this paper: AISI 303 stainless steel and 6060-T5 Aluminum alloy. The objective is to study the effects of multiaxial loading paths on the crack initiation and orientation of the two materials studied. Fatigue tests were conducted in a biaxial testing machine. Fractographic analyses of the fracture surface were carried out by optical microscope and SEM approaches. In addition to the experimental studies, theoretical predictions of the damage plane were made using critical plane approaches. Comparisons of the predicted orientation of the damage plane with the experimental observations are shown. The applicability of the multiaxial fatigue criteria for the two materials is discussed. It was shown that the two materials studied have different crack orientations under the same loading path. This observation appears to show that the applicability of the fatigue models is dependent on the material type and multiaxial microstructure characteristics.

Residual Stress State at Different Scales in Deep Drawn Cup of Unstable Austenitic Steel

2006 ◽  
Vol 524-525 ◽  
pp. 95-100 ◽  
Author(s):  
M. Reda Berrahmoune ◽  
Sophie Berveiller ◽  
Karim Inal ◽  
Etienne Patoor
Keyword(s):  
Stress State ◽  
Residual Stresses ◽  
Austenitic Steel ◽  
Deep Drawing ◽  
Complex Loading ◽  
Tensile Tests ◽  
Loading Path ◽  
Internal Stresses ◽  
Drawing Ratio ◽  
Unstable Austenitic Steel

In this study, residual stresses state at different scales in the 301LN unstable austenitic steel after deep drawing was determined. The first part of the work deals with the characterization of the martensitic transformation during uniaxial loading. The austenite/martensite content which was determined by X-Ray Diffraction increases until a maximum of 0.6 for 30% strain. Internal stress distribution was determined by coupling in-situ tensile tests with sin²ψ method. As soon as martensite appears, the magnitudes of the internal stresses in this phase were found to be 400 MPa higher than in the austenite. To establish a relation between the complex loading path effect and the phase stress state, deep drawing tests were carried out for different drawing ratios. Both macroscopic tangential residual stresses and residual stresses in the martensite were determined. It appears that the macroscopic tangential residual stresses are positive and increase with increasing drawing ratios and the maximum value is located at middle height of the cup. It is about 850MPa for the Drawing Ratio (DR)=2.00. The tangential residual stresses in the martensite were found to be positive in the external face and have a same evolution as the macroscopic ones.

Determination of Residual Stresses after Tensile Tests and Deep Drawing of Unstable Austenitic Steel

2005 ◽  
Vol 490-491 ◽  
pp. 690-695 ◽  
Author(s):  
M. Reda Berrahmoune ◽  
Sophie Berveiller ◽  
Karim Inal ◽  
Etienne Patoor ◽  
Christian R. Simon ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Deep Drawing ◽  
Complex Loading ◽  
Tensile Tests ◽  
Loading Path ◽  
X Ray Diffraction ◽  
Martensite Content ◽  
Different Temperatures ◽  
Kinetics Of

The main objective of this work is to contribute to the study of the 301LN unstable austenitic stainless steel by determining the distribution of residual stresses after deep drawing, taking into account the phase transformation. In the first part, kinetics of martensitic transformation are determined for uniaxial loading. Tensile tests are performed at different pre-strains at room temperature for two different strain rates. The austenite/martensite content is measured by X-ray diffraction and is coupled with the determination of residual stresses distribution. In addition, to establish a relation between the complex loading path effect and the residual stresses state, deep drawing are done for different drawing ratios for two different temperatures. Macroscopic tangential residual stresses are determined by the separation technique. It appears that the residual stresses increase with increasing drawing ratios and the maximum value is located at middle height of the cup.

scholarly journals The Behavior of a Coarse Granular Material under Complex Stress Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yuefeng Zhou ◽  
Jiajun Pan ◽  
Zhanlin Cheng ◽  
Yongzhen Zuo
Keyword(s):  
Granular Material ◽  
Principal Stress ◽  
Stress Ratio ◽  
Intermediate Principal Stress ◽  
Friction Reduction ◽  
Western China ◽  
Triaxial Tests ◽  
Confining Stress ◽  
True Triaxial ◽  
Prediction Approach

In recent years, dozens of high rockfill dams are under construction or planning for hydropower exploration in western China. In dam construction, the mechanical behavior of coarse granular material greatly affects the compatible deformation of dam body. In this article, an indirect in situ density prediction approach for coarse granular material is firstly proposed to solve the technical obstacle on prediction of the material density in thick overburden layer of a dam site in southwest China. Adopting a self-developed large-scale true triaxial apparatus with a special friction-reduction technique, four series of true triaxial tests were then performed to investigate the behavior of a coarse granular material with a maximum particle diameter of 60 mm. Test results show that the peak strength of the material increases together with the increasing confining stress and the increasing intermediate principal stress ratio. The material dilatancy is restricted by both the confining stress and the intermediate principal stress ratio. With the increase in intermediate principal stress ratio, the internal friction angle increases firstly and then decreases slightly, but the slope of stress path reduces gradually. The tested peak states were compared with several well-known strength criteria under the framework of generalized stress, showing a good fitness with the Lade–Duncan criterion and underestimation by the Mohr–Coulomb criterion and the Matsuoka–Nakai criterion. The strength envelope in the π plane shrinks with the increasing confining stress.

scholarly journals Mesoscale inertial transition in granular materials

2021 ◽  
Vol 249 ◽  
pp. 10004
Author(s):  
Adriane Clerc ◽  
Antoine Wautier ◽  
Stéphane Bonelli ◽  
François Nicot
Keyword(s):  
Kinetic Energy ◽  
Discrete Element Method ◽  
Granular Material ◽  
Granular Materials ◽  
Failure Mode ◽  
Discrete Element ◽  
Loading Path ◽  
Failure Patterns ◽  
Granular Assemblies ◽  
Failure State

Granular assemblies can experience complex failure patterns along a given loading path, with a distribution of ephemeral inertial events marked by local outbursts in kinetic energy. However, investigating such mechanisms appears to be necessary to understand how a certain failure mode develops in a granular material. Using a discrete element method, this study highlights several microstructure reorganizations before the specimen reaches a proper failure state. Meso structures have proven to be efficient to understand the elementary mechanisms responsible for these outbursts in kinetic energy. Strain–like and stress-like quantities are thus defined at a mesoscale and they are used to characterize the nucleation and propagation of these local microstructural events.

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