Modelling of elastic interaction stresses in two-phase materials by FEM

Greene, Charles A.; Ankem, Sreeramamurthy

doi:10.1016/0921-5093(95)09786-4

Cited by 15 publications

(6 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the microstructureinduced constraint is inherently higher at internal sites, subsurface crack nucleation at the primary a grains located in the interior is more favorable compared to surface grains. Previous FEM modeling of bicrystals [24,25] has shown that elastic interaction stresses can cause the initiation of slip in the a or the b phase in an a + b Widmanstatten colony at stresses below the macroscopic yielding stress. However, the need of five independent deformation (slip and twin) systems within an individual grain for macroscopic plastic flow to occur reduces the importance of elastic interaction stresses acting on a particular slip system in a given grain or phase.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, these authors have investigated the experimental stressstrain behavior of two-phase Ti alloys under uniaxial tension [18,19,21] for materials with various amounts of a (hcp) and b (bcc) grains at ambient temperature, where the a grains are softer and the b grains are harder at ambient temperature. [18][19][20][21][22][23] The experimental data [18,19,21] and the corresponding elastic-plastic FEM analyses of a model two-phase a + b microstructure in a polycrystalline material [18,20] or in a bicrystal [24,25] showed that the softer a grains are more highly strained than the harder b grains, resulting in strain gradients and plastic interactions between the soft and the hard grains. [18,20,21] The heterogeneous plastic deformation and the interaction stresses depend on the morphology, volume fraction, and the crystallographic relationships of the two ductile phases with different inelastic flow properties.…”

Section: Introductionmentioning

confidence: 98%

“…[21] Under certain conditions, elastic interaction stresses can initiate slip in the a phase or the b phase at stresses below the macroscopic yield stress, depending on the sign of the interaction stresses. [21,24,25] Yield and ultimate tensile strengths of two-phase Ti alloys can be described by the rule-of-mixtures only when the positive interactions in the softer phase are cancelled by negative interactions in the harder phase. [21] These authors, however, did not present results on the distribution of mean stresses in individual phases or their dependence on volume fraction.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Deformation-Induced Constraint on High-Cycle Fatigue in Ti Alloys with a Duplex Microstructure

Chan

Lee

2008

Metall Mater Trans A

View full text Add to dashboard Cite

The effects of the deformation behaviors of individual phases in Ti alloys with a duplex microstructure containing a mixture of primary a grains and lamellar a + b colonies have been analyzed by applying the finite-element method (FEM) to the relevant microstructure. The softer primary a grains and the harder lamellar a + b colonies are treated as distinct microstructural units with different constitutive properties. The FEM results indicate that the softer (primary a) phase, which reaches yielding first, tends to concentrate both the plastic strain and the hydrostatic stress, whose magnitudes depend on the volume fraction of the primary a grains and the load levels. The insight from the FEM analyses has been used to modify the linear relation between alternating stress and mean stress in a Haigh or modified Goodman diagram by incorporating a microstructure-induced hydrostatic stress term, leading to a set of bilinear relations for high-cycle fatigue (HCF) failures of Ti alloys with a duplex microstructure. The applicability of the micromechanical approach to treating the mean stress effects in HCF failure of Ti-6Al-4V with various duplex microstructures is elucidated by comparison against experimental data in the literature.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Deformation-Induced Constraint on High-Cycle Fatigue in Ti Alloys with a Duplex Microstructure

Chan

Lee

2008

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…The misorientation distribution resulting from tensile plastic deformation of the γ-austenite and δ-ferrite phases were investigated by the EBSD technique using a FEI Inspect Field Emission Gun (FEG) scanning electron microscope (SEM) instrument equipped with TSL EBSD detector. Specimens taken from the transverse section of the tensile specimen gauge lengths were prepared by standard metallographic techniques followed by jet electropolishing using a [15], [31]. The displacement was applied to the equivalent of 0.1% strain, which is within the elastic deformation region.…”

Section: Electron Backscatter Diffraction (Ebsd)mentioning

confidence: 99%

Characterization of phase properties and deformation in ferritic-austenitic duplex stainless steels by nanoindentation and finite element method

Schwarm

Kolli

Aydoğan

et al. 2017

Materials Science and Engineering: A

View full text Add to dashboard Cite

The phase properties and deformation behavior of the δ-ferrite and γ-austenite phases of CF-3 and CF-8 cast duplex stainless steels were characterized by nanoindentation and microstructure-based finite element method (FEM) models. The elastic modulus of each phase was evaluated and the results indicate that the mean elastic modulus of the δ-ferrite phase is greater than that of the γ-austenite phase, and the mean nanoindentation hardness values of each phase are approximately the same. The elastic FEM model results illustrate that greater von Mises stresses are located within the δ-ferrite phase, while greater von Mises strains are located in the γ-austenite phase in response to elastic deformation. The elastic moduli calculated by FEM agree closely with those measured by tensile testing. The plastically deformed specimens exhibit an increase in misorientation, deformed grains, and subgrain structure formation as measured by electron backscatter diffraction (EBSD).

show abstract

“…Stress-strain interactions have been modeled and analyzed successfully via finite element methods (FEM), notably by Greene and Ankem [10]. Model interfaces simplified to bi-crystals and tri-crystals were created and tested to verify the above modified rule of mixtures equations with considerable success.…”

Section: Computational Models Of Interaction Stressmentioning

confidence: 99%

Recent Advances on the Deformation Behavior of Two-Phase α+β Titanium Alloys

Ankem

Joost

Schwarm

2019

MSF

View full text Add to dashboard Cite

Two-phase materials, such as α+β Titanium (Ti) alloys, are technologically important. A number of factors can affect deformation behavior, including the interaction stresses between phases, the crystallographic relationships between phases, and the morphology. As a result, the deformation mechanisms of two-phase alloys may be different from the individual single-phase materials. For example, twinning may not occur in a single phase material if the grain size is very small but twinning can occur in a very fine grained alloy if the second phase contributes to the interfacial stresses due to elastic interactions. Interaction stresses can result from the difference in the elastic properties of the two phases. In particular, these elastic interaction stresses can be quantified by the finite element method (FEM). In this paper recent developments regarding two-phase deformation mechanisms will be reviewed and the ramifications on mechanical behavior in regard to two-phase Ti alloys in particular and on two-phase metallic materials in general will be outlined.

show abstract

Modelling of elastic interaction stresses in two-phase materials by FEM

Cited by 15 publications

References 11 publications

Effects of Deformation-Induced Constraint on High-Cycle Fatigue in Ti Alloys with a Duplex Microstructure

Effects of Deformation-Induced Constraint on High-Cycle Fatigue in Ti Alloys with a Duplex Microstructure

Characterization of phase properties and deformation in ferritic-austenitic duplex stainless steels by nanoindentation and finite element method

Recent Advances on the Deformation Behavior of Two-Phase α+β Titanium Alloys

Contact Info

Product

Resources

About