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User subroutine for Calculix explicit

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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.

s.faraji's picture

Radial of support domain in SPH

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 Hi all.I test the proficiency of SPH method dealing with a benchmark numerical example solving Poisson's equation; SPH  shows the good efficiency in modeling the contours, but the value of re

s.faraji's picture

Radial of support domain in SPH

I test the proficiency of SPH method dealing with a benchmark numerical example solving Poisson's equation; SPH  shows the good efficiency in modeling the contours, but the value of results change for a di

shahram's picture

how can I deal with the thickness strain in the Shell elements (S4R) writing a VUMAT subroutine ?

Hey buddies


I am writing a constitutive relation in vumat for plane stress conditions with S4R elemet in the ABAQUS.

the problem is that the E33 is reported as zero where it is not zero and also the values for S11 and S22 are so large numbers. 

ihave tried the code for 3D conditions and it work great with C3D8R element and the results are satisfactory where for the Shell elements by enforcing the S33=0, the E33 gets zero too.

does anybody have any solution? 


thanks alot

Bin Liu's picture

The theoretical ultimate magnetoelectric coefficients of magnetoelectric composites by optimization design

This paper investigates what is the largest magnetoelectric (ME) coefficient of ME composites, and how to realize it. From the standpoint of energy conservation, a theoretical analysis is carried out on an imaginary lever structure consisting of a magnetostrictive phase, a piezoelectric phase, and a rigid lever. This structure is a generalization of various composite layouts for optimization on ME effect.

Research Position Available in System Modeling and Control

Research Position Available in System Modeling and Control

Research Position Available in Structural Joints Simulation

Research Position Available in Structual Joints Simualtion

Research Position Available in Engine Simulation


Research Position Available in Engine Simulation


Crack Propagation in Bamboo's Hierarchical Cellular Structure

Bamboo, as a natural hierarchical cellular material, exhibits remarkable mechanical properties including excellent flexibility and fracture toughness. As far as bamboo as a functionally graded bio-composite is concerned, the interactions of different constituents (bamboo fibers; parenchyma cells; and vessels.) alongside their corresponding interfacial areas with a developed crack should be of high significance.

How to mesh , a solid/ shell hemisphere , hexdominant either by sweep or mapped meshing in ANSYS APDL ?

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Can anyone guide me how to mesh solid and shell 3d hemisphere with hex dominant approach in ansys mechanical APDL?

I found no such verification manual for 3d hemispherical meshing in ansys. What method should be applied and what element should be chosen appropriately to mesh this structure?

I have attached screen shot for your understanding of my problem.

Your response will be highly appreciated.


Hello ANSYS masters, I am student of M.Tech and I am currently doing my dissertation on Friction stir welding stimulation using ANSYS Mechnical APDL. The problem I face is in defining the time substep in the load step defined as follows

!Load Step2
d,1,rotz,nr1             !Rotation of tool, 60rpm

Cohesive Zone modelling

Dear all,

           I am trying to study the fracture at bonded interfaces using cohesive zone model in Abaqus. I am going through the abaqus manual but it was not clear how to insert the chosive elements in the model. How to model these chosive elements. Can anyone help in modelling the chosive elements.   

Amir Abdollahi's picture

A computational study of flexoelectricity

Flexoelectricity is a size-dependent electromechanical mechanism coupling polarization and strain gradient. It exists in a wide variety of materials, and is most noticeable for nanoscale objects, where strain gradients are higher. Simulations are important to understand flexoelectricity because experiments at very small scales are difficult, and analytical solutions are scarce.

VUMAT Subroutines for multi-phase material behavior.

Hi everyone. I would like to know how to get started with a VUMAT subroutine for multiphases for example a subroutine for pore water and sand. It could be helpful when anyone could share VUMAT subroutines for learning such complex programmings. Could be appreciated when some one teaches with equations. thank you.

coupled temp-displacement analysis ABAQUS CAE: predefined field problem

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Hi I'm new in abaqus, I'm trying to make a coupled temp-displacement analysis with abaqus, but I cant fix an initial velocity in the predefined field in the inital step (I mean I can, but it doesn't work during the calculations), I already did the same thing with dynamic implicit analysis and it worked good

Ettore Barbieri's picture

Extremely Curved Cracks


The word "extreme" seems to be "trending" a lot these days, see the recent discussions on the new journal Extreme Mechanics Letters.

My collaborator Ruben Sevilla at Swansea and I were interested in very curved crack paths that develop in nature and have been replicated experimentally in thin films attached to elastic substrates.

WaiChing Sun's picture

Journal Club Theme of September 2014: Numerical modeling of thermo-hydro-mechanical coupling processes in porous media

Thermo-hydro-mechanics (THM) is a branch of mechanics aimed to predict how deformable porous media behave, while heat transfer and fluid transport simultaneously occur in the pores filled by liquid and/or gas. Understanding these multi-physical responses is important for a wide spectrum of modern engineering applications, such as tissue scaffolding, geothermal heating, mineral exploration and mining, hydraulic fracture, energy piles, tunneling with frozen soil and nuclear waste storage and management.

Determination of the elastic properties of rabbit vocal fold tissue using uniaxial tensile testing and a tailored finite element model


Uniaxial tensile testing of rabbit vocal fold tissue.
Investigating the role of specimen shape on tensile testing of vocal fold tissue.
Development of a shape-specific finite element model to estimate elastic modulus.
Comparison of elastic moduli from shape-specific and generic-shape models.
Yonggang Huang's picture

Rapid review and publication at JAM in 2014

Journal of Applied Mechanics (JAM) received 280 submitted manuscripts during the first 6 months in 2014.  Among them only 4 are still in review.  

The average time for the 1st round of review, with the decision to accept, or reject, or revise, is reduced to 10 days.  For those that need revisionsthe average time to make the final decision is 24 days after the 1st round of review, which include both the authors' revision time and 2nd (and more) round(s) of review.


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