Options
Anand Krishna Kanjarla
Loading...
Preferred name
Anand Krishna Kanjarla
Official Name
Anand Krishna Kanjarla
Alternative Name
Kanjarla, A. K.
Kanjarla, Anand
Kanjarla, Anand K.
Kanjarla, Anand Krishna
Main Affiliation
Email
ORCID
Scopus Author ID
Google Scholar ID
4 results
Now showing 1 - 4 of 4
- PublicationAn experimental and crystal plasticity investigation of anisotropic compression behaviour of Mg-Sn-Ca alloy(25-05-2023)
;Paramatmuni, Chaitanya ;Bandi, AnilThe ductility of Magnesium alloys is often limited due to the strong basal texture. Initial attempts were made to reduce the intensity of the basal textures by adding rare earth(RE) elements. However, owing to the cost and scarcity of RE elements, alloys with calcium and tin were recently introduced. Among them, Mg-2Sn-2Ca alloys are the most promising, with high strength reported in the extruded condition. In this work, we report, for the first time, the mechanical properties of the alloy in the sheet form. In plane mechanical anisotropy in compressive behaviour is studied along with the detailed characterisation of texture, microstructure and the deformation twins in the material. Unlike strongly basal textured Mg alloys, deformation twinning was also observed in samples loaded along the normal direction. Crystal plasticity simulations were performed to confirm the slip and twin activity. Furthermore, a detailed analysis of deformation twins revealed that the so called Schmid twins accommodate strain by both twin growth and slip, whereas the non-Schmid twins accommodate the strain exclusively by crystallographic slip. - PublicationA crystal plasticity FFT based study of deformation twinning, anisotropy and micromechanics in HCP materials: Application to AZ31 alloy(01-02-2019)
;Paramatmuni, ChaitanyaIn this paper, an infinitesimal-strain based FFT formulation is extended to account for deformation twinning in hexagonal close-packed (HCP) materials. A model called the Complex Voxel (CV) model is developed that includes twinning as pseudo-slip and accounts for interaction between parent grains and corresponding twin variants by assuming a Taylor-type approximation at the voxel level. The macroscopic deformation behavior of Magnesium alloy AZ31, a representative HCP material, is simulated in three different loading directions. Detailed analysis of twinning dominated deformation reveals that: (a) Global Schmid factors indicate twin variant selection and the rate of twin growth; (b) Basal slip is the dominant active slip system during the twin nucleation and twin growth stages; (c) A comparison of numerical results of the present study with the published experimental and numerical studies indicate that the evolution of local stress states in parent grains and corresponding twin variants depend on their orientation with respect to the loading direction and/or the neighbouring grains. Further, the need of immediate experimental evidence to assist assumptions made during modelling deformation twinning is discussed. - PublicationNumerical study of the stress state of a deformation twin in magnesium(01-02-2015)
;Arul Kumar, M.; ;Niezgoda, S. R. ;Lebensohn, R. A.Tomé, C. N.We present here a numerical study of the distribution of the local stress state associated with deformation twinning in Mg, both inside the twinned domain and in its immediate neighborhood, due to the accommodation of the twinning transformation shear. A full-field elastoviscoplastic formulation based on fast Fourier transformation is modified to include the shear transformation strain associated with deformation twinning. We have performed two types of twinning transformation simulations with: (i) the twin completely embedded inside a single crystal and (ii) the twin front terminating at a grain boundary. We show that: (a) the resulting stress distribution is more strongly determined by the shear transformation than by the intragranular character of the twin or the orientation of the neighboring grain; (b) the resolved shear stress on the twin plane along the twin direction is inhomogeneous along the twin-parent interface; and (c) there are substantial differences in the average values of the shear stress in the twin and in the parent grain that contains the twin. We discuss the effect of these local stresses on twin propagation and growth, and the implications of our findings for the modeling of deformation twinning. - PublicationRole of deformation twinning and second phase on the texture evolution in a duplex stainless steel during cold rolling: Experimental and modelling study(07-04-2020)
;Chalapathi, Darshan ;Sivaprasad, P. V.Deformation twinning is known to be one of the reasons that cause texture transition (copper type to brass type) in single phase fcc materials and is studied extensively. The role of deformation twinning in two phase materials is an area yet to be explored. Similarly in two phase materials, the effect of one phase on the texture evolution of the other phase is not well understood. In this work, a combination of experiments and modelling are used to address their effects on texture evolution in duplex stainless steels. The material is cold rolled to 80% thickness reduction and texture evolution is studied at various strain levels. These are compared with a series of crystal plasticity simulations using the Taylor model and grain interaction based LAMEL model which was extended to a two phase material. Deformation twinning in austenite is incorporated by predominant twin reorientation (PTR) scheme. It is observed that only by accounting for the strong local interactions between the phases, the correct textures are predicted. The texture transition from {001}〈110〉 to {112}〈110〉 orientation observed in ferrite at higher strain levels is attributed to deformation twinning in austenite. A number of simulations with ideal orientations observed in fcc and bcc materials are performed to assess the role of one phase on texture evolution of the other. It is concluded that experimental observations are also required to comment on the dominant phase during texture evolution.