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Dario Schiano Moriello's picture

Application of Corotational Formulation

Hello,  I am a PhD student in Mechanical Engineering, and at the moment I am studying the co-rotational formulation from Criesfield's books.

I am looking for applications of the corotational formulation in ABAQUS or MATLAB; my supervisor suggested me it could be done in ABAQUS through a User Defined Element Subroutine, but being a new user to this software I don't really know from where I should start.

Dario Schiano Moriello's picture

Implementation of Corotational Formulation

Hello,
I am a PhD student in Mechanical Engingeering.

I am currently studying the co-rotational formulation, following the theory on Crisfield's books. The next step in my project would be to apply the corotational formulation for the simulation of a beam, and my supervisor suggested me this could be done in ABAQUS through a User Defined Element Subroutine.

Second derivatives of displacement field ABAQUS

 

Hello everyone,

 

I need to compute the second derivatives of displacement field in ABAQUS, in the integration point of quadratic elements if it is possible. I thought about using USDFLD subrutine, but I am stuck with getting the Jacobian matrix that couples the isoparametric space with the physical space in ABAQUS. GETVRM is what everyone suggests to get variables from abaqus, however I did not find the definitions of JMAC, JMATYP... so I do not know what I can get from that subrutine exactly.

 

computational nonlinear elasticity references

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I will be developing constitutive material models into commercial FE codes for nonlinear elasticity and searching for good books to get started for computational aspects. There are many good books for computational plasticity but I did not find any for nonlinear elasticity. Suggestion for good books or references is welcome.

ABAQUS - increase the size of the interior elements

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Hello everyone,

I am currently working on modelling ITZ zones in concrete 2D microstructure. ITZ is the cement paste zone near the surface of aggregate which differs in properties from bulk cement paste. The thichness of ITZ zone ranges from 10-50 micrometer (0.01 - 0.05 mm). The size of RVE I am using is 100X100 mm which makes ITZ a very fine detail in my microstructure. I have created a instance in abaqus merging all parts, Aggregate, ITZ and Matrix( Cement Paste).

I seeded the instance with using these parameter:

Global Size: 2

ABAQUS XFEM error message: std_findcutoneedge3d8_xfem

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Hi everyone,

After switching from a working 2D model to 3D, I'm facing the following error message after about 20 iteration steps:

The system error in std_findcutoneedge3d8_xfem -- nodal level set values might not be correct for element 12345 instance FEM_MODEL_V1

Xinlei_Wu's picture

Periodic displacement loads decompose with 4 load steps in Abaqus

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 I want to simulate a dynamic motion of a pipe under periodic displacement loads.

Hidroxid's picture

Pressure load on element-based surface? or converting element-based surface to geometric surface to apply pressure in abaqus?

I would like to use pressure load on a element based surface, in Abaqus. This surface is a combination of small surface elements (in an orphan mesh). But to apply pressure load you need to have a geometic surface.

How can I do this? Is it possible to make a geometric surface using this element-based surface?

 

Regards,

Omid

 

Using libraries in Abaqus subroutines

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Hi,
Can someone comment on using libraries in Abaqus subroutines?

How to generate mesh based surfaces in Abaqus using python scripting?

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Hi,

I am trying to generate an element based surface in Abaqus using python scripts. I need to create this surface in order to create an offset layer of solid elements using the offset mesh method in the edit mesh dialogue. It is not possible to use this feature using geometry based surfaces. The surface that I would like to generate is not all in one plane, I think this may add to my difficulty (see image, part). If I were able to generate an element based surface from a geometry based surface this would also work for me as I can easily generate a geometry based surface.

Abaqus 3d Tunnel model

hi

im making a 3d model of a tunnel excavation and its subsequent settlement using abaqus.

i have made a model in which the tunnel is excavated to a certain section. but my problem is that i cant simulate the progress of excavation. for example a model in which the tunnel gets excavated in 2-meter steps. and in each step 2 meter of soil gets excavated.

i have searched the internet and i think there are plug-ins which can help doing this. can anyone tell me how i can download such plug-ins? or introduce me another way to model the progress of the tunnel excavation?

create shell planar in 2D model ? (Abaqus 6.13)

Hi,

I have modeling a ground in abaqus and simulated earthquake. will i need allow infinite elements in the laterals model (left and right). In other examples i see in the features (module part) created  "shell planar" en the places to create the infinite element (edge, no plane)... so .. how its made ?

 

thanks. 

PD: Me english is terrible, sorry.

 

ABAQUS: Calculating area of a Solid Of Revolution

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Hello,

I would like to calculate the area and volume of the solid of revolution obtained by revolving a sketch. I have used the query tool (mass properties) to get such values. The volume is OK but the area is equal to zero. How can this be possible? This is the warning I get from abaqus:

"Warnings: Some mass properties could not be computed due to the following issues detected while querying the selected region(s) - zero thickness, zero material density, missing section definition."

Solution-Dependent State Variables Defined in Subroutine FRIC Cannot be Displayed in ABAQUS Visualization Module

Hi,

 

I am now using ABAQUS subroutine FRIC to define some solution-dependent state variables, and I am currently able to check these values throung writing them into a TXT file in the subroutine. However, I cannot find these SDVs displayed in the ABAQUS visualization module although I have already specify them in the Field/History output manager.

 

I will be appreciate if anyone could give me some advice on this.

 

Thanks a lot,

Yi 

Iriene Elok's picture

Error about Degree of Freedom 11 in Abaqus

Hi friends, I'm new here and also new using abaqus.

I need to do my final project about bird strike analysis using abaqus. But for now, I try to follow the tutorial from youtube about impact bullet first. For some trial sometimes i found errors and never succeed to solve it. Included the impact bullet trial. This is what i've got:

errors:

Degree of freedom 11 and at least one of degrees of freedom 1 thru 6 must be active in the model for *dynamic temp-disp. Check the procedure and element types used in this model.

warnings:

New publication for UMAT and VUMAT in ABAQUS

We performed a comprehensive study of a large class of Implicit and Explicit integration algorithms for Elastic-Plastic behaviors in Finite Element Analysis (FEA) developed in UMAT and VUMAT for ABAQUS and presented various unique results. We also showed detailed integration algorithms for both Associated and Non-Associated Flow Rules with mixed isotropic and kimenatic hardening with expandable number of internal variables (damage and etc).

Full bibliographic details:

Thermal stresses Abaqus

Hi all,

I have a  20 node hexahedral "Thermomechanical" element in our inhouse software which i am trying to validate against Abaqus .

The problem is, the displacements, nodal forces match exactly ( Just compared the max min values in the legends! and checked a few random nodes).

The Abaqus input file is attached:

The problem is as follows:

One single element is chosen with a linear elastic material model (Some parameters are chosen in an unphysical manner but here the idea is

to just validate the implementation):

Applying periodic boundary condition

Attached paper supplies detailed procedure and necessary scipt for applying PBC.

 

Opening for Senior Engineer in BD Corporate CAE Group

The Corporate CAE group for Becton Dickinson is looking for a CAE Senior Engineer at the Research Triangle Park, NC USA location (Raleigh-Durham area).

Dincoz's picture

what is the reason for Large element deformation?

Hi my Friends,

I am doing abaqus run for a copper specimen under hydrostatic pressure. The magnetude of pressure is in order of several Giga Pascals. In my material definition, I have defined stress-strain flow up to strain of 0.4. But as you can see in attached photo, some elements show very large deformation (considerably larger than 0.4). Knowing that I have not defined stress strain behaviour for srain greater than 0.4, how this can be occure? Unfortunately, niether adaptive meshing nor element deletation were not eliminate this issue!!

 

Best Thanks

Frank Richter's picture

Subroutine DFLUX in ABAQUS

Dear Mechanicians,

time and again the question of modeling moving heat sources pops up, often in the context of laser heating.

One can achieve this using the subroutine DFLUX in ABAQUS.

I decided to post some links here to avoid responding with a longer explanation to every individual seeking assistance.

Please note that I have never worked with any one of these codes and have no access to ABAQUS at present.

No warranty is given by me.

Frank Richter's picture

ABAQUS built-in SMA model

Dear Mechanicians,

time and again the question of SMA (shape memory alloy) modeling pops up.

In ABAQUS, you can achieve this only by (V)UMAT coding or by using the little-known built-in SMA model.

In the past I have frequently responded to queries on SMA modeling and could refer to a customer help site of SIMULIA. That site is down, regrettably.

I decided to post the files here to avoid responding with a longer explanation to every individual seeking assistance and uploading the files as E-mail attachment every time.

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