A study of microstructure-driven strain localizations in two-phase polycrystalline HCP/BCC composites using a multi-scale model

Ardeljan, Milan; Knežević, Marko; Nizolek, Thomas J.; Beyerlein, Irene J.; Mara, Nathan A.; Pollock, Tresa M.

doi:10.1016/j.ijplas.2015.06.003

Cited by 146 publications

(43 citation statements)

References 130 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In other words, shear banding that would prevail within the microstructures after large rolling reductions is suppressed in the subsequently heat-treated samples. The similar observation has also been reported in a recent work by Ardeljan et al 40) . This validates the importance of applying intermediate annealing between the contiguous ARB cycles in this work (500 C for 90 min).…”

Section: Mechanical Stability Of the Annealed Compositessupporting

confidence: 92%

“…This con rmed that recrystallization and even grain growth are the most important features for Cu when the composite is fabricated at 300 C. The mixed microstructures in the both Ti and Cu contribute to the limited increase of strength and the retained ductility of the bulk composites during ARB. ARB has been previously utilized for other material systems composed of at least one hcp metal, such as Ni-Ti 5) , Al-Mg 10,19,26) and Nb-Zr 40) . According to those, ARB is usually carried out at temperatures lower than 0.5 T m (T m : melting point), so as to prevent signi cant grain growth of the constituent metals.…”

Section: Microstructuresmentioning

confidence: 99%

See 1 more Smart Citation

Microstructure and Mechanical Properties of Multilayered Cu/Ti Composites Fabricated by Accumulative Roll Bonding

et al. 2017

View full text Add to dashboard Cite

Multilayered composites composed of pure copper and titanium (Cu/Ti) have been fabricated by accumulative roll bonding (ARB). The macroscopic lamellar structures, mechanical properties and microstructures of the composites are investigated. The results show that the Cu and Ti layers are bonded well during the ARB processing. With the increasing number of ARB cycles, Ti layers start to neck, fracture and even segregate within the Cu matrix, which is attributed to the activation of shear bands that cut through the multiple metal layers. At larger ARB cycles, the distribution of small fragmentations of Ti inside the Cu matrix is more homogeneous, which is attributed to the fact that the outer surfaces of the previously processed composite are placed in the interior of the subsequent ARB stack. Tensile testing at room temperature shows that the yield strength and the ultimate strength of the composites increased mildly with the increasing ARB cycles, while the uniform elongation of the composites is retained. Microhardness tests reveal that the increase of strength in the composites during ARB mainly results from the reinforcement of the Ti layers. The mechanical behaviors of the composites can be attributed to the effect of the mixed microstructures in the both constituent metals.

show abstract

Section: Mechanical Stability Of the Annealed Compositessupporting

confidence: 92%

Section: Microstructuresmentioning

confidence: 99%

Microstructure and Mechanical Properties of Multilayered Cu/Ti Composites Fabricated by Accumulative Roll Bonding

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Stored dislocation density can, however, serve to resist expansion of twin lamellae. More details of this dislocation density (DD) hardening model as it applies to α-U [13] as well as other metals, like FCC pure Cu [82], AA6022 [83], and Haynes 25 [84] or BCC Ta [85,86] and Nb [87] or HCP Zr [88][89][90], Be [10], and Mg [4], can be found in prior works. Below we provide an abbreviated review of this model.…”

Section: Model For α-Umentioning

confidence: 99%

Anisotropic modeling of structural components using embedded crystal plasticity constructive laws within finite elements

Knežević

Crapps

Beyerlein

et al. 2016

International Journal of Mechanical Sciences

Self Cite

View full text Add to dashboard Cite

a b s t r a c tPins are commonly used to join members of mechanical mechanisms. In order to maintain the integrity of the joint and prevent failure, there must be sufficient material of adequate strength around the pin hole to sustain the bearing and tear out loads from the pin connection. In this work, a multi-scale materials simulation model based on finite elements (FE) is developed for design and evaluation of materials for such applications. We specifically examine several constitutive models for simulating the elasto-plastic behavior of the plate material while maintaining computational efficiency. Here, models are developed for two plate materials: copper (Cu) and α-uranium (α-U), with vastly different plastic behaviors owing to their crystal structures and crystallographic textures. For Cu, digital image correlation (DIC) tests are carried out during loading of the plate/pin assembly to characterize the strain distributions in the critical hole/pin area. The corresponding FE simulations are carried out using a combination of constitutive laws involving a fine-scale polycrystal plasticity calculation, a J2 flow theory, or a combination of both. We show that the FE model using the fine-scale polycrystal plasticity constitutive law successfully captures the DIC strain fields in the hole region at different plate displacements. Surprisingly, use of the more computationally efficient J2 plasticity model also produces reasonable results in comparison with the measurements and the fine-scale constitutive law. An interesting finding is that combining fine-scale constitutive laws in the region surrounding the hole and continuum J2 theory elsewhere gives the worst agreement. It also precariously produces non-conservative estimates for the hole opening with applied displacement. These results on Cu helped subsequent simulations on α-U, where use of the fine-scale polycrystal simulation is fundamental considering the highly plastic anisotropic response of this complicated material. We demonstrate that in the α-U plates, the localized deformation in the hole region is highly dependent on the direction of displacement.

show abstract

“…These forces are the main ingredient that governs the kinematics of particles through local laws, which leads to the macroscopic strain. Once grain loops collapse, the force chain will be broken and significant displacements will appear . Therefore, the failure of the sample is triggered by the instability of the grain loops.…”

Section: Introductionmentioning

confidence: 99%

“…1,2,4,5,7,8,18,19 Micromechanical investigations have demonstrated that global instabilities in granular materials originate from the rearrangements of grain loops and the collapses of force chains. 1,10,[20][21][22][23][24][25][26][27][28][29] Given these findings, two questions can be raised: What criterion can be used to characterise the instabilities at various scales and how is the extent of global instability related to elementary and microstructural instabilities in granular materials? In current numerical studies based on phenomenological constitutive relations with different methods, it appears that neither the finite element method 18,30,31 nor the second gradient theory 32,33 can consider in a simultaneous manner the instabilities of granular materials at the interparticle level, the laboratory scale, and the engineering scale.…”

mentioning

confidence: 99%

A multiscale approach for investigating the effect of microstructural instability on global failure in granular materials

Zhao

Yin

Hicher

2018

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

Summary This paper aims to develop a multiscale approach that has the ability to characterise the influence of microstructural instabilities on global failures in granular materials. For this purpose, the Chang‐Hicher multiscale constitutive relation has been implemented into a finite element code, and the expression of the second‐order work, as an indicator of the material instability, has been computed at the interparticle contact scale, at the representative element volume scale, and at the boundary value problem scale. At the global scale, the second‐order work can be obtained through the integration of that obtained at interparticle contacts. Hence, it becomes possible to analyse the range of instability from the microstructure to the macrostructure. Drained and undrained triaxial tests were numerically simulated. With this method, it was demonstrated that the grain‐scale origin of the specimen instability was well captured. Additionally, biaxial tests were conducted and the onsets of localised and diffuse failure in granular assemblies were successfully predicted. The transition from diffuse to localised failure was demonstrated at different scales, whereby the coincidence between the direction of local instabilities and the direction of the shear band became evident. The influence of the boundary conditions and of the heterogeneity of the initial porosity on the failure mode of granular materials was also analysed. All these examples demonstrate that the developed multiscale approach can characterise in a satisfactory manner the influence of instability at the inter‐grain contacts upon the global failure of granular assemblies.

show abstract

A study of microstructure-driven strain localizations in two-phase polycrystalline HCP/BCC composites using a multi-scale model

Cited by 146 publications

References 130 publications

Microstructure and Mechanical Properties of Multilayered Cu/Ti Composites Fabricated by Accumulative Roll Bonding

Microstructure and Mechanical Properties of Multilayered Cu/Ti Composites Fabricated by Accumulative Roll Bonding

Anisotropic modeling of structural components using embedded crystal plasticity constructive laws within finite elements

A multiscale approach for investigating the effect of microstructural instability on global failure in granular materials

Contact Info

Product

Resources

About