Hello all,
Can anyone please tell me that how can I see subroutine requested output in ABAQUS odb display? I am able to print some results in .log file but I want to see results in odb display. Is it possible?
Thanks in advance
Abhishek
Hello everybody,
My task is to write a UMAT for Non-linear Viscoelasicity based on Schapery's model in ABAQUS. I have coded the routine, but I am still not able to predict correct response. I tried to debug it as much as I can. I understand that it would be difficult for anybody to understand my code. So, I have attached a flowchart (pdf) of the whole algorithm that I follow. It would be nice if you could check that and correct me if I am wrong.
Thanks in advance for your time and consideration
Dear All,
I want to do some single element tests for a plane stress quadratic element with bi-linear shape functions(like the plane 42 element in ANSYS).
What I am not sure about is what boundary conditions should be applied to the single element in this case. I also want to apply a prescribed displacement as the loading. (I would like to first try to do these single element simulations in Ansys and then with my own developed codes, hopefully the results will conform, as sort of a basic validation of my own developed code)
We develop a microstructure-based model to characterize and model failure initiation in DP steels using an extended finite element method (XFEM) to simulate martensite cracking on the mesoscale combined with representative volume element (RVE) modeling. A mini tensile test with digital image correlation (DIC) analysis is linked to local SEM analysis to identify the local strain at which failure is initiated.
Chiqun Zhang Xiaohan Zhang Amit Acharya Dmitry Golovaty Noel Walkington
Nonsingular disclination dynamics in a uniaxial nematic liquid crystal is modeled within a mathematical framework where the kinematics is a direct extension of the classical way of identifying these line defects with singularities of a unit vector field representing the nematic director. It is well known that the universally accepted Oseen-Frank energy is infinite for configurations that contain disclination line defects. We devise a natural augmentation of the Oseen-Frank energy to account for physical situations where, under certain conditions, infinite director gradients have zero associated energy cost, as would be necessary for modeling half-integer strength disclinations within the framework of the director theory. Equilibria and dynamics (in the absence of flow) of line defects are studied within the proposed model. Using appropriate initial/boundary data, the gradient-flow dynamics of this energy leads to non-singular, line defect equilibrium solutions, including those of half-integer strength. However, we demonstrate that the gradient flow dynamics for this energy is not able to adequately describe defect evolution. Motivated by similarity with dislocation dynamics in solids, a novel 2D-model of disclination dynamics in nematics is proposed. The model is based on the extended Oseen-Frank energy and takes into account thermodynamics and the kinematics of conservation of defect topological charge. We validate this model through computations of disclination equilibria, annihilation, repulsion, and splitting. We show that the energy function we devise, suitably interpreted, can serve as well for the modeling of equilibria and dynamics of dislocation line defects in solids making the conclusions of this paper relevant to mechanics of both solids and liquid crystals.
Amit Acharya Michael Widom
To appear in Journal of the Mechanics and Physics of Solids
Motivated by results of the topological theory of glasses accounting for geometric frustration,
we develop the simplest possible continuum mechanical model of defect dynamics in metallic
glasses that accounts for topological, energetic, and kinetic ideas. A geometrical description
of ingredients of the structure of metallic glasses using the concept of local order based on
Frank-Kasper phases and the notion of disclinations as topological defects in these structures is
proposed. This novel kinematics is incorporated in a continuum mechanical framework capable
of describing the interactions of disclinations and also of dislocations (interpreted as pairs of
opposite disclinations). The model is aimed towards the development of a microscopic understanding
of the plasticity of such materials. We discuss the expected predictive capabilities of
the model vis-a-vis some observed physical behaviors of metallic glasses.
Hi Everyone,
I have now managed to run the fortran code, but it won't assign the values that I want to assign to the U(1) variable from the TXT file.
In the attached file I have the Fortran file that I am working on, the input file Subroutine1 (save it as .inp file to open in Abaqus) and the pressure file that contains the nodes and the corresponding pressure values which I want to assign through DISP Subroutine. The code below
The effect of crystal size and initial dislocation density on surface roughness evolution in FCC single crystals during the early number of cycles of mechanical cyclic loading is investigated using three dimensional discrete dislocation dynamics simulations. Crystals having size less than 2 μm show early development of surface slip localization, while larger ones show a more uniform distribution of surface steps. The surface roughness is found to increase with increasing number of loading cycles with larger crystals showing a high roughening rate compared to smaller crystals.
Shuze Zhu* and Teng Li*, Strain-induced programmable half-metal and spin-gapless semiconductor in an edge-doped boron nitride nanoribbon, Physical Review B, 93, 115401 (2016)
