User login

You are here

research

Abaqus Standard/CFD

Hi, I'm trying to solve a problem with heat transfer and fluid. When I co-execute heat transfer model and CFD model, the following error is encountered "An unrecoverable error has been encountered with the co-simulation engine".

Can anyone help me solving this error?

Gratefull for your attention.

Cracks found at reactor at Hunterston B nuclear power station

Perhaps some of those on this site have seen the news article on the BBC website yesterday about cracks appearing in the reactor at the Hunterston B nuclear power station. As the article states, cracking in the graphite bricks is predicted and the regulators are happy that the reactor is safe to operate.

Problem relating to Contact Pressure in ABAQUS Subroutine

I have already obtained the contact pressure (CPRESS) in the ABAQUS model.

NOW, I want to introduce a subroutine in ABAQUS which enables setting the contact pressure as input information, since contact pressue is the intial condition for another model which will incorporate with the existing model. I wonder if anyone can provide some suggestions on which subroutine can read the CPRESS (CSTRESS) as input information.

Many thanks!

SIMPLE ACOUSTICS PROBLEM

DEAR all

I want to knowthe following:

A circular diaphragm of 1mm diameter, is vibrating with the amplitude of 100 microns at frequency 1000 Hz. What is the sound output at 10 mm distance??

Shuze Zhu's picture

Pseudomagnetic Fields in a Locally Strained Graphene Drumhead

Recent experiments reveal that a scanning tunneling microscopy (STM) probe tip can generate a highly localized strain field in a graphene drumhead, which in turn leads to pseudomagnetic fields in the graphene that can spatially confine graphene charge carriers in a way similar to a lithographically defined quantum dot (QD). While these experimental findings are intriguing, their further implementation in nanoelectronic devices hinges upon the knowledge of key underpinning parameters, which still remain elusive.

Variation of Stress with Charging Rate due to Strain-Rate Sensitivity of Silicon Electrodes of Lithium Ion Batteries

Silicon is a promising anode material for lithium-ion batteries due to its enormous theoretical energy density. Fracture during electrochemical cycling has limited the practical viability of silicon electrodes, but recent studies indicate that fracture can be prevented by taking advantage of lithiation-induced plasticity. In this paper, we provide experimental insight into the nature of plasticity in amorphous LixSi thin films. To do so, we vary the rate of lithiation of amorphous silicon thin films and simultaneously measure stresses.

Leon Mishnaevsky's picture

Micromechanics of hierarchical materials: a brief overview

A short overview of micromechanical models of hierarchical materials (hybrid composites, biomaterials, fractal materials, etc.) is given. Several examples of the modeling of strength and damage in hierarchical materials are summarized, among them, 3D FE model of hybrid composites with nanoengineered matrix, fiber bundle model of UD composites with hierarchically clustered fibers and 3D multilevel model of wood considered as a gradient, cellular material with layered composite cell walls.

Algorithm for Contact Pressure (CPRESS) in ABAQUS

Does anybody know the underlying algorithm for the contact pressure in ABAQUS. Is the contact pressure calculated from the stresses?

Many thanks in advance!

ABAQUS model for viscoelastic peel dynamics

Choose a channel featured in the header of iMechanica: 

Hi All,

Davide Bigoni's picture

Torsional locomotion

Can a torque induce longitudinal motion of an elastic rod?

See the explanation and an example of use of the 'torsional gun' at http://www.ing.unitn.it/~bigoni/torsional_locomotion.html

If you're having trouble playing videos on YouTube, click here to watch it.

abedford's picture

Hamilton's principle

I continue to receive inquiries about the monograph Hamilton's Principle in Continuum Mechanics, published in 1985 as Research Notes in Mathematics No. 139 by Pitman Publishing, Ltd. Now out of print, it is in the public domain and is attached here. My initial objective in writing it was to discuss the theoretical foundations of the applications of Hamilton's principle to mixtures that I had developed with D. S. Drumheller and others during the preceding decade.

Shixuan Yang's picture

Stretchability and compliance of freestanding serpentine-shaped ribbons

High-performance stretchable electronics have to utilize high-quality inorganic electronic materials such as silicon, oxide or nitride dielectrics, and metals. These inorganic materials usually crack or yield at very small intrinsic strains, for example, 1%, whereas bio-integrated electronics are expected to at least match the stretchability of bio-tissues (20%) and deployable structure health monitoring networks are expected to expand from wafer scale (several centimeters) to cover macroscopic structures (several meters).

Zhigang Suo's picture

Mechanics of supercooled liquids

In a pure liquid, molecules touch one another but change neighbors frequently.  External forces cause the liquid to change shape by viscous flow.  Thermal agitation causes  molecules to undergo self-diffusion.  The two phenomena--viscous flow and self-diffusion--often result from a single rate-limiting process:  molecules change neighbors.  This simple picture is amply confirmed by the Stokes-Einstein relation, which links the viscosity and self-diffusivity for many liquids over wide ranges of temperature.

Cihan Tekoğlu's picture

Representative Volume Element Calculations under Constant Stress Triaxiality, Lode Parameter, and Shear Ratio

Recent experiments showed that the Lode parameter, which distinguishes between axisymmetric and shear dominated stress states, has a profound effect on material ductility, especially at low stress triaxiality. Consequently, the theoretical framework for void growth and coalescence is currently being revisited, which often involve performing representative volume element (RVE) calculations. The present study investigates an RVE composed of a cubic unit cell containing a spherical void at its center.

Leon Mishnaevsky's picture

Hybrid and hierarchical nanoreinforced polymer composites

Hybrid and hierarchical polymer composites represent a promising group of materials for engineering applications. In this paper, computational studies of the strength and damage resistance of hybrid and hierarchical composites are reviewed. The reserves of the composite improvement are explored by using computational micromechanical models. It is shown that while glass/carbon fibers hybrid composites

Leon Mishnaevsky's picture

Graphene reinforced polymer composites: 3D micromechanical modelling, damage and fracture

3D computational model of graphene reinforced polymer composites is developed and applied to the analysis of damage and fracture mechanisms in the composites. The graphene/polymer interface properties are determined using the inverse modeling approach. The effect of composite structure, in particular, of the aspect ratio, shape, clustering, orientation and volume fraction of graphene platelets on the
mechanical behavior and damage mechanisms of nanocomposites are studied in computational experiments.

Sutured tendon repair; a multi-scale finite element model.

We've recently published an open access journal paper that looks at the mechanics of sutures used to repair severed tendons. A homogenization strategy is used to derive effective elastic properties for tendon fibrils and intracellular matrix. We have found that regions of high stress correlate with the regions of cell death (necrosis) that are sometimes observed in patients.

If this is of interest, please feel free to view the paper here.

 

 

User subroutine for Calculix explicit

Choose a channel featured in the header of iMechanica: 

Hello,

I want to use Calculix explicit for large deformation problem. I want to use a user subroutine similar to vuhard (in ABAQUS) to model the material behaviour. Calculix documentation metions uhardening, but there is nothing similiar to vuhard.

Is there a way to do this?

Hamid Torabi's picture

Micromechanics of collective buckling in CNT turfs

Complex structures consisting of intertwined, nominally vertical carbon nanotubes (CNTs) are called turfs. Under uniform compression experiments, CNT turfs exhibit irreversible collective buckling of a layer preceded by reorientation of CNT segments. Experimentally observed independence of the buckling stress and the buckling wavelength on the turf width suggests the existence of an intrinsic material length.

Pages

Subscribe to RSS - research

Recent comments

More comments

Syndicate

Subscribe to Syndicate