Nabble - Abaqus Users

Fixing Initial Deflection

2009-11-24T19:34:06Z

hi, I am trying to model a reinforced concrete interior beam-column connections subjected to static loads in Abaqus Standard.

firstly, both the beam ends are initially loaded by a static load to simulate the effects of gravity. this permanent vertical deflection is fixed but the both end of the beams is allowed to move laterally when a static lateral load is applied to the end of the bottom beam.

how can i apply the static load of both end of the beam in the first step and fixed this vertical displacement before applying the lateral load onto the column in the following step.

thank you.

Re: Problem with parameterized input files

2009-11-24T18:49:46Z

Dear dave,

Thank u very much for the reply. The problem solved :)

rgrds;
shima shaffiar

On Tue, Nov 24, 2009 at 11:16 PM, Dave Lindeman <ddlindeman@...> wrote:

> The input file apparently contains a *PARAMETER section, and the
> parameter values are referenced later in the file. Perform a
> search-and-replace to replace the parameter references with their actual
> numerical values, then attempt the import again.
>
> Regards,
>
> Dave
>
> -------------------------
> Dave Lindeman
> Lead Research Specialist
> 3M Company
> 3M Center 235-3F-08
> St. Paul, MN 55144
> 651-733-6383
>
>
> shi wrote:
> >
> >
> > Dear sir
> >
> > I have encountered this problem when importing an input file taken from
> > the abaqus documentation 6.9. When i imported the file in abaqus cae,
> > this warning appeared
> >
> > "WARNING: The input file contains one or more data items which have been
> > parameterized. Parameterized input files can not yet be imported into
> > Abaqus/CAE. This occurred while scanning input file for parameterized
> > data. The input file will not be imported."
> >
> > Why? Can anybody help me?
> >
> > rgrds;
> >
> > Shima shaffiar
> >
> >
>
>
> ------------------------------------
>
> Community email addresses:
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[Non-text portions of this message have been removed]

Simple Tensile Test using Single Element

2009-11-24T15:25:46Z

Hi All,

I run a simple simulation of a tensile test using a single element using my
UMAT. I strain the element in the Z direction using a displacement boundary
condition and use symmetry boundary conditions on rare Z face, one of the X
faces and one of the Y faces. I am simulating aluminum single crystal which
rotates during deformation. Due to this rotation the faces of the element do
not remain parallel to each other during deformation as they would be during
an experiment because the ends are constrained in the jaws.

I want to keep the faces of the element parallel during the whole
simulation. Could anybody suggest any constrains/coupling/tie/ or boundary
conditions I need to use?

Thanks,

--
Alankar
Ph.D. Candidate - Mechanical Engineering
School of Mechanical and Materials Engineering
Washington State University, Pullman
WA 99164-2920
USA

[Non-text portions of this message have been removed]

Re: Calculating the simulation time for Explicit

2009-11-24T14:30:57Z

Hi Dave,

I am using explicit because I am trying to model progressive damage of composite material. This leads to very small time step in the implicit analysis.

I tried to run a frequency analysis for the whole joint however for some reason it does not work. It never finishes, keeps going on. I am not sure what to do about it.

Thanks for your help.

Regards

Maajid

--- In Abaqus@..., Dave Lindeman <ddlindeman@...> wrote:

>
> If the joint is bolted together, then the two plates should stay in
> contact in the overlap region. I would perform the modal analysis
> assuming bonded contact at the interface.
>
> You mention that you intend to analyze the joint under tension. This
> sounds like a static analysis that should be performed using Standard.
> Is the load dynamic, or is there some other reason you intend to use
> Explicit?
>
> Regards,
>
> Dave
>
> -------------------------
> Dave Lindeman
> Lead Research Specialist
> 3M Company
> 3M Center 235-3F-08
> St. Paul, MN 55144
> 651-733-6383
>
>
> maajidchishti wrote:
> >
> >
> > Dear All,
> >
> > I am modelling a single lap bolted composite joint under tension. I am
> > aware that to calculate the simulation time for explicit analysis we
> > have to run frequency analysis.
> >
> > I saw example in abaqus manual which suggests to remove the contacts,
> > surfaces etc from the frequency analysis model and run the frequency
> > analysis for the main part of the model.
> >
> > However, I have some doubts:
> >
> > My model has two composite plate attached using a bolt. If I follow the
> > abaqus example, then I need to delete all the contacts etc. I am not
> > sure if that is the correct way to do it?
> >
> > If I run the frequency analysis for the composite plate which is fixed
> > in the model I get very small frequency and therefore very high step
> > time. So I not sure if this approach is correct.
> >
> > It will be great if someone can tell me how should I do frequency
> > analysis for my model to find the simulation time.
> >
> > Thanks in advance.
> >
> > Regards
> >
> > Maajid
> >
> >
>

Re: Analysis coupling an implicit step and an explicit one

2009-11-24T14:07:29Z

Yes and no. You can't define both Standard and Explicit steps within
the same model in CAE, but you can define a model for the first of the
steps, solve it, then create an input file that uses *IMPORT to bring
the model and state into the next solver (and define subsequent load
steps, etc.).

Alternatively, in 6.9 you can use the new co-simulation to couple
Standard and Explicit subregions simultaneously. See the release notes
and documentation for further information.

Regards,
Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

Olivier_D wrote:

>
>
>
> Hi everybody,
>
> I would like to know if it's possible to do an analysis within a first step
> would be done with Abaqus Standard and a second one with Abaqus Explicit.
> This using Abaqus CAE.
>
> The purpose is to save time while large step time are used and then when
> step times have to be very low (when damage occurs for instance) to be able
> to switch into an explicit analysis.
>
> If you know how to do it, could you advice me, please.
>
> Thanks for your help
>
> Olivier D.
> --
> View this message in context:
> http://old.nabble.com/Analysis-coupling-an-implicit-step-and-an-explicit-one-tp26499902p26499902.html
> <http://old.nabble.com/Analysis-coupling-an-implicit-step-and-an-explicit-one-tp26499902p26499902.html>
> Sent from the Abaqus Users mailing list archive at Nabble.com.
>
>

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Re: abaqus user subroutine into obj file

2009-11-24T14:01:55Z

In the "site" directory of your ABAQUS installation. For example:

C:\ABAQUS\6.9-1\site

Note that for Explicit, VABA_PARAM.INC gets mapped to either
VABA_PARAM_DP.INC or VABA_PARAM_SP.INC, depending on the precision being
used.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

swang wrote:

>
>
> Dave,
>
> Do you know where to find those contents of code? I couldn't find it
> anywhere.
>
> Thanks,
>
> Wang
>
> --- On Mon, 11/23/09, Dave Lindeman <ddlindeman@...
> <mailto:ddlindeman%40mmm.com>> wrote:
>
> From: Dave Lindeman <ddlindeman@... <mailto:ddlindeman%40mmm.com>>
> Subject: Re: [Abaqus] abaqus user subroutine into obj file
> To: Abaqus@... <mailto:Abaqus%40yahoogroups.com>
> Date: Monday, November 23, 2009, 6:59 PM
>
> Rather than using the INCLUDE statement, simply paste the contents of
> VABA_PARAM.INC directly into your source code.
>
> Regards,
>
> Dave
>
> -------------------------
> Dave Lindeman
> Lead Research Specialist
> 3M Company
> 3M Center 235-3F-08
> St. Paul, MN 55144
> 651-733-6383
>
> swang wrote:
> >
> >
> > Hi, guys:
> >
> > I want compile vumat into object file so that it can run in ABAQUS
> > without exposing source code. When I use Intel Fortran to compile the
> > vumat, it always says can't open 'VABA_PARAM.INC.
> >
> > Does anyone knows how to get around this problem so that I get .o file?
> >
> > Regards,
> >
> > Wang
> >
> > [Non-text portions of this message have been removed]
> >
> >
>
> ------------------------------------
>
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Re: Weight Force / Acceleration Forces / Loads

2009-11-24T10:35:44Z

Thank you very much for your help....

I am really gratefull

Eftyhia

Dave Lindeman wrote:

1) Define the density for each material (*DENSITY), and define a
gravitational load (*DLOAD w/ load type label "GRAV"). ABAQUS will
figure out the rest.

2) I suspect that you want to apply forces to the mast and calculate
the accelerations, displacements, etc. rather than specifying the
accelerations directly. You can use concentrated forces (*CLOAD) or
distributed loads (*DLOAD).

3) Pressure always acts normal to the surface. As you've discovered,
surface traction is more general -- you specify which direction it acts in.

4) Uniformly distributed force acting on the edge.

5) The on-line documentation that should have been installed when you
installed ABAQUS has everything -- CAE User's Manual, ABAQUS User's
Manual, Theory Manual, Examples Manual, etc. There is an extraordinary
wealth of information there. You can purchase printed versions if you
prefer.

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

edalma wrote:
>
>
>
> Hallo....
>
> I am a beginner at abaqus and i am trying to make a simulation of the loads
> acting on a mast of a vessel.
>
> I have made my model in CAE. I attach a photo so that you could have an idea
> of the model.
>
> My questions concern not only abaqus itself but are also enginnering
> problems (how to simulate the acting loads).
>
> 1) The first question relates to the weight of the structure. I want my
> simulation to take account the weight of the structure itself, since at the
> top of the mast there is a structure which weight the mast i am afraid
> cannot hold.
>
> How can this be defined in abaqus? Do I have to calculate myself the weight
> force (F=m*g) of each part and act same on it ?
>
> Is there an alternative to define material density, and having defined the
> material (thickness) of each shell part the program to calculate itself the
> weight force ?
>
> How do i define material density, define gravity acceleration, and load
> weight force?
>
> 2) Due to the fact that the mast is on the ship, acceleration in all
> directions x,y,z are acting on it.
>
> I suppose that i can act loads in x,y,z directions (Fx=m*ax / Fy=m*ay /
> Fz=m*az).
>
> I have seen that in the Load Tab there is an option Body Force and another
> option gravity .What is the difference between these two? Which one should i
> use?
>
> Can I use either of these two options so as to act the accelerations to my
> whole model in all three directions without having to calculate myself the
> mass and concequently the force for each part of the model?
>
> 3) What is the difference between surface traction and pressure ?
>
> The only difference that i have detected is that in case of the surface
> traction you can define the in which direction the uniform force is
> applied.
>
> I assume that in both cases the magnitude is in load/area and in MPa in case
> of SI-mm
>
> 4) The option Load Tab<Shell edge load is uniform weight acting on an edge?
>
> In such case, the magnitude is in load/area and in MPa in case of SI-mm ?
>
> 5) Finally, is there a manual describing in detail all the function of
> Abaqus? For example the manual Getting Started wuth Abaqus does not contain
> details for Load Tab.
>
> --
> View this message in context:
> http://old.nabble.com/Weight-Force---Acceleration-Forces---Loads-tp26443590p26443590.html
> <http://old.nabble.com/Weight-Force---Acceleration-Forces---Loads-tp26443590p26443590.html>
> Sent from the Abaqus Users mailing list archive at Nabble.com.
>
>

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Analysis coupling an implicit step and an explicit one

2009-11-24T10:03:28Z

Hi everybody,

I would like to know if it's possible to do an analysis within a first step would be done with Abaqus Standard and a second one with Abaqus Explicit. This using Abaqus CAE.

The purpose is to save time while large step time are used and then when step times have to be very low (when damage occurs for instance) to be able to switch into an explicit analysis.

If you know how to do it, could you advice me, please.

Thanks for your help

Olivier D.

Re: Zero Thickness Cohesive Elements

2009-11-24T08:08:33Z

If you know the density of the adhesive, then you need to multiply by
the ACTUAL thickness of the adhesive (zero thickness is only a modeling
abstraction).

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

iratxe mijangos wrote:

>
>
> Hi all,
>
> I am confused about cohesive elements of zero thickness.
>
> Reading the manual 27.5.6 it says that the density i sdefined as mass
> per unti area instead of volume, which means I have to multiply by the
> thickness of the cohesive element, so my density is zero and my
> stiffness interface is infinite.
> Do I have to give a value of zero for the density or reducing it few
> orders of magnitude would be good enough ans the oppossite for the
> stiffness?
> Is this correct?
>
> Thank you,
>
> Iratxe
>
> [Non-text portions of this message have been removed]
>
>

Re: Satellite thermal analysis

2009-11-24T07:30:24Z

The problem shouldn't have anything to do with the STEP import from
CATIA (though I'd recommend using an ACIS or Parasolids file instead).

Have you defined the absolute zero reference value (*PHYSICAL CONSTANTS,
or Model->Edit Attributes->[model name]), or are you working directly
with absolute temperature values? Are you applying the radiation using
*RADIATE? If so, are you ramping or stepping the ambient temperature?

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

francisco bedmar wrote:

>
>
>
> Hello everybody,
>
> I am doing my master thesis and part of it is to do thermal analysis of
> a satellite. I have a simple model of it in CATIA V5 which I have
> imported to Abaqus as a ".stp" file. At the moment I am only applying
> radiation equivalent to the solar one and taking into account just the
> conduction. As contanct properties are not transfered from CATIA to
> Abaqus I find them with contact pairs. I apply to steps, one to imply a
> initial temperature equal for the whole model and another step for the
> radiation.
>
> My problem is that during the second step it gives me the error "too
> many attempts for this increment" due to a fall of the temperature below
> the absolute zero in some point of the structure. I have refine the mesh
> several times obtaining very fine meshes but the problem persist.
>
> What can I do? Can it be a problem due to the importation of a file from
> CATIA?
>
> Thanks for your help,
>
> Francisco
>
> __________________________________________________________
> Sólo hay un loro experto en Windows 7 en todo el mundo. Y vive en Sietes
> ¡Cónocelo!
> http://www.sietesunpueblodeexpertos.com/
> <http://www.sietesunpueblodeexpertos.com/>
>
> [Non-text portions of this message have been removed]
>
>

Re: Problem with parameterized input files

2009-11-24T07:16:08Z

The input file apparently contains a *PARAMETER section, and the
parameter values are referenced later in the file. Perform a
search-and-replace to replace the parameter references with their actual
numerical values, then attempt the import again.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

shi wrote:

>
>
> Dear sir
>
> I have encountered this problem when importing an input file taken from
> the abaqus documentation 6.9. When i imported the file in abaqus cae,
> this warning appeared
>
> "WARNING: The input file contains one or more data items which have been
> parameterized. Parameterized input files can not yet be imported into
> Abaqus/CAE. This occurred while scanning input file for parameterized
> data. The input file will not be imported."
>
> Why? Can anybody help me?
>
> rgrds;
>
> Shima shaffiar
>
>

Re: abaqus user subroutine into obj file

2009-11-24T04:18:48Z

Dave,

Do you know where to find those contents of code? I couldn't find it anywhere.

Thanks,

Wang

--- On Mon, 11/23/09, Dave Lindeman <ddlindeman@...> wrote:

From: Dave Lindeman <ddlindeman@...>
Subject: Re: [Abaqus] abaqus user subroutine into obj file
To: Abaqus@...
Date: Monday, November 23, 2009, 6:59 PM

Rather than using the INCLUDE statement, simply paste the contents of
VABA_PARAM.INC directly into your source code.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

swang wrote:

>
>
> Hi, guys:
>
> I want compile vumat into object file so that it can run in ABAQUS
> without exposing source code. When I use Intel Fortran to compile the
> vumat, it always says can't open 'VABA_PARAM.INC.
>
> Does anyone knows how to get around this problem so that I get .o file?
>
> Regards,
>
> Wang
>
> [Non-text portions of this message have been removed]
>
>

Satellite thermal analysis

2009-11-24T03:10:57Z

Hello everybody,

I am doing my master thesis and part of it is to do thermal analysis of a satellite. I have a simple model of it in CATIA V5 which I have imported to Abaqus as a ".stp" file. At the moment I am only applying radiation equivalent to the solar one and taking into account just the conduction. As contanct properties are not transfered from CATIA to Abaqus I find them with contact pairs. I apply to steps, one to imply a initial temperature equal for the whole model and another step for the radiation.

My problem is that during the second step it gives me the error "too many attempts for this increment" due to a fall of the temperature below the absolute zero in some point of the structure. I have refine the mesh several times obtaining very fine meshes but the problem persist.

What can I do? Can it be a problem due to the importation of a file from CATIA?

Thanks for your help,

Francisco

_________________________________________________________________
Sólo hay un loro experto en Windows 7 en todo el mundo. Y vive en Sietes ¡Cónocelo!
http://www.sietesunpueblodeexpertos.com/

[Non-text portions of this message have been removed]

Problem with parameterized input files

2009-11-24T01:00:55Z

Dear sir

I have encountered this problem when importing an input file taken from the abaqus documentation 6.9. When i imported the file in abaqus cae, this warning appeared

"WARNING: The input file contains one or more data items which have been parameterized. Parameterized input files can not yet be imported into Abaqus/CAE. This occurred while scanning input file for parameterized data. The input file will not be imported."

Why? Can anybody help me?

rgrds;

Shima shaffiar

Zero Thickness Cohesive Elements

2009-11-24T00:57:46Z

Hi all,

I am confused about cohesive elements of zero thickness.

Reading the manual 27.5.6 it says that the density i sdefined as mass per unti area instead of volume, which means I have to multiply by the thickness of the cohesive element, so my density is zero and my stiffness interface is infinite.
Do I have to give a value of zero for the density or reducing it few orders of magnitude would be good enough ans the oppossite for the stiffness?
Is this correct?

Thank you,

Iratxe

[Non-text portions of this message have been removed]

frictional condition modeling

2009-11-24T00:57:43Z

Hi,
we use some different models for frictional conditions. one of them in friction stress=m*K that K is maximum shear stress according to yield stress( usually .577*Y).
Is there any way to create this friction model in ABAQUS CAE?
if not can we use VFRIC subroutine to model this? how?

Kind Regards
Amir,

[Non-text portions of this message have been removed]

How to edit part(Geometry) in an INP file??!!

2009-11-24T00:03:47Z

Hi all

I want to edit one INP format and I do not have its CAE. I want to change
the geometry of previous example.

When I import this INP, the meshes changes to Orphan mesh and part is not editable.

Do you have any idea how can I edit the parts of previous example?

Should I delete the previous geometry and draw my model? Is there any other
simple way, because some surfaces have been defined in previous file and
finding these surfaces is time consuming.

Thanks in advance.

Regards

Victor

[Non-text portions of this message have been removed]

Too many attempts made for this increment

2009-11-23T20:44:18Z

haii ariasef,

In your problem, first check if there is load given a greater value, or check for contact. if the contact is given and the other part is hanging in air, it won't take any contact. so check for these things.

The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. http://in.yahoo.com/

[Non-text portions of this message have been removed]

Re: Kinetic energy Abaqus

2009-11-23T11:47:21Z

The kinetic energy in ABAQUS is certainly based on (1/2)mv^2, and m is
based on density and volume. If you're asking whether ABAQUS integrates
over the element volume to account for the velocity distribution, or
whether it uses the total element mass and an average nodal velocity,
I'm not sure (and I doubt it matters much). Perhaps the Theory Manual
goes into that kind of detail.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

iramijan wrote:
>
>
> Hi all,
> Does anybody know how the kinetic energy is defined in Abaqus?
> Is it 1/2mv^2 and also 1/2*density*vol element* (displ/steptime )^2?
> Thanks,
> Iratxe
>
>

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Re: abaqus user subroutine into obj file

2009-11-23T11:41:36Z

The vaba_param include files (single and double precision) are usally
located in the site subdirectory. You may have to use the compile command in
the abaqus_v6.env in order to get this to work.

On Mon, Nov 23, 2009 at 8:39 AM, swang <swwang_tut@...> wrote:

>
>
> Hi, guys:
>
> I want compile vumat into object file so that it can run in ABAQUS without
> exposing source code. When I use Intel Fortran to compile the vumat, it
> always says can't open 'VABA_PARAM.INC.
>
> Does anyone knows how to get around this problem so that I get .o file?
>
> Regards,
>
> Wang
>
> [Non-text portions of this message have been removed]
>
>
>

[Non-text portions of this message have been removed]

Re: Progressive Element deletion during laser melting

2009-11-23T11:40:30Z

One option would be to define temperature-dependent properties such that
elements become very soft once they've melted. Within Viewer you can
remove elements with temperature above a certain value so that they
appear to be disappearing. Alternatively, you could add
temperature-dependent damage initiation and evolution definitions to
your mechanical material property definition so that the elements due,
in fact, fail.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

Sohail Akhtar wrote:

>
>
> Dear friends
>
> I am working on laser heating with moving source with subsequent stress
> analysis. I have successfully implemented the DFLUX routine in
> simulating the thermal analysis with sequential coupling with stress
> analysis. However, I dont know how to delete/kill those elements whose
> temperature goes beyond the melting temperature during laser heating so
> that I could get the accurate stress results during the stress analysis
> step. Can anybody guide me in this issue?
>
> Thanks in advance
>
> Regards
>
> Sohail
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around
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>
> [Non-text portions of this message have been removed]
>
>

Re: Weight Force / Acceleration Forces / Loads

2009-11-23T11:36:02Z

1) Define the density for each material (*DENSITY), and define a
gravitational load (*DLOAD w/ load type label "GRAV"). ABAQUS will
figure out the rest.

2) I suspect that you want to apply forces to the mast and calculate
the accelerations, displacements, etc. rather than specifying the
accelerations directly. You can use concentrated forces (*CLOAD) or
distributed loads (*DLOAD).

3) Pressure always acts normal to the surface. As you've discovered,
surface traction is more general -- you specify which direction it acts in.

4) Uniformly distributed force acting on the edge.

5) The on-line documentation that should have been installed when you
installed ABAQUS has everything -- CAE User's Manual, ABAQUS User's
Manual, Theory Manual, Examples Manual, etc. There is an extraordinary
wealth of information there. You can purchase printed versions if you
prefer.

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

edalma wrote:

>
>
>
> Hallo....
>
> I am a beginner at abaqus and i am trying to make a simulation of the loads
> acting on a mast of a vessel.
>
> I have made my model in CAE. I attach a photo so that you could have an idea
> of the model.
>
> My questions concern not only abaqus itself but are also enginnering
> problems (how to simulate the acting loads).
>
> 1) The first question relates to the weight of the structure. I want my
> simulation to take account the weight of the structure itself, since at the
> top of the mast there is a structure which weight the mast i am afraid
> cannot hold.
>
> How can this be defined in abaqus? Do I have to calculate myself the weight
> force (F=m*g) of each part and act same on it ?
>
> Is there an alternative to define material density, and having defined the
> material (thickness) of each shell part the program to calculate itself the
> weight force ?
>
> How do i define material density, define gravity acceleration, and load
> weight force?
>
> 2) Due to the fact that the mast is on the ship, acceleration in all
> directions x,y,z are acting on it.
>
> I suppose that i can act loads in x,y,z directions (Fx=m*ax / Fy=m*ay /
> Fz=m*az).
>
> I have seen that in the Load Tab there is an option Body Force and another
> option gravity .What is the difference between these two? Which one should i
> use?
>
> Can I use either of these two options so as to act the accelerations to my
> whole model in all three directions without having to calculate myself the
> mass and concequently the force for each part of the model?
>
> 3) What is the difference between surface traction and pressure ?
>
> The only difference that i have detected is that in case of the surface
> traction you can define the in which direction the uniform force is
> applied.
>
> I assume that in both cases the magnitude is in load/area and in MPa in case
> of SI-mm
>
> 4) The option Load Tab<Shell edge load is uniform weight acting on an edge?
>
> In such case, the magnitude is in load/area and in MPa in case of SI-mm ?
>
> 5) Finally, is there a manual describing in detail all the function of
> Abaqus? For example the manual Getting Started wuth Abaqus does not contain
> details for Load Tab.
>
> --
> View this message in context:
> http://old.nabble.com/Weight-Force---Acceleration-Forces---Loads-tp26443590p26443590.html
> <http://old.nabble.com/Weight-Force---Acceleration-Forces---Loads-tp26443590p26443590.html>
> Sent from the Abaqus Users mailing list archive at Nabble.com.
>
>

Re: How to edit input file with CAE(change geometry, mesh and surfaces)!!??

2009-11-23T11:27:32Z

If all you have is an input file, then there's very little you can do to
modify the geometry. You can obviously write simple scripts and
programs to do basic translation, rotation, and scaling operations, but
if you need to do anything more elaborate, you'll probably have to
re-create the geometry in CAE (or a CAD package) and go from there.

I'm not aware of any method for getting around import limitations or errors.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

Victor wrote:

>
>
> Hi all.
> I have a input file and I want to change the gemetry of previuos model
> in it. There are some modules and subroutines that are not supprted in CAE.
>
> I could inport the file but with errors and warnings.
> In fact in previous model lots of surfaces has been defined, so how can
> I find out which surfaces are those to define new surfaces in CAE.
>
> Also how can I define new nodes and meshes in new model.
>
> Thanks in advance.
> Regards
> Victor
>
> [Non-text portions of this message have been removed]
>
>

Re: abaqus user subroutine into obj file

2009-11-23T10:59:24Z

Rather than using the INCLUDE statement, simply paste the contents of
VABA_PARAM.INC directly into your source code.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

swang wrote:

Re: Too many attempts made for this increment

2009-11-23T08:58:29Z

HI
I am a MSc student from BUET . i am modelling a Rcc beam using ABAQUS.The dimension of the beam is 200mmX300mmX3000mm. i choosed elemnt size 200mmX30mmX50mm . Used the general static step.

for concrete i euse
*elastic
33000, 0.2
*concrete
17.4,0� (i used 17.4=0.45*.85*f'c=fy)
34.5,0.0029 � (34.5= 0.85*fic)
*tension stiffening
1,0
0,0.193
*FAILURE RATIOS
1.16 ,0.09,1.28,0.333

for steel i am using
*elastic
200000,0.31
*PLASTIC
439.964,0
753.13,0.1785
*embedded element,host elset=all_conc_elements
reinforcement

the problem is , i am getting much stiffer result. the initial portion of the load displacement curve is at a much higher (load almost double) position. i am also not getting the displacement correct. i get result up to 10 mm of displacement but the experimental curve has 80 mm displacement. In the msg file i find the same message everytime Too many attempts made for this increment. also there are negetive eigen values.

If any one can suggest me about this stiffer result, it would be a great help

Thanking You

Ashraf
BUET

--- On Fri, 20/11/09, looyong <looyong@...> wrote:

From: looyong <looyong@...>
Subject: Re: [ABAQUS] Too many attempts made for this increment
To: ABAQUS@...
Date: Friday, 20 November, 2009, 6:57 PM

I encountered the same problem with Abaqus Standard when applying a static

load to a reinforce concrete element. What I did was:

1) At Step module, i used the Static-General Procedure

2) I click on Automatic Stabilization> Use Damping Factors from previous

general Step> Use Adaptive Stabilization with max ratio of stabilization to

strain energy: 0.05

3) Try to increase the minimum increment size to say 1E-09.

This does the trick for me. I do not get the "Too many attempts made for

this increment" anymore. However, I am not getting the right results (my

model seems to be too stiff). So I am not really sure if I am right. You can

try it out.

Rgds,

Joseph

--

View this message in context: http://old.nabble. com/Too-many- attempts- made-for- this-increment- tp26421238p26443 638.html

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Re: Restart option in Abaqus Explicit

2009-11-23T08:48:06Z

Over-riding the default time step size used in Explicit probably won't
help, unless the time step size is being controlled by elements
associated with the VUMAT, and the VUMAT is returning information that
results in the use of an incorrect stable time increment. In this case,
however, the VUMAT needs to be corrected. That particular error message
is often associated with severe deformations in an element. Have you
tested the shear stability of your VUMAT?

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

hibrunda wrote:

>
>
> Dear all,
>
> I am working on constitutive modeling using VUMAT (Abaqus explicit)
>
> I have a sheet specimen (thickness is considerably smaller compared to
> other dimensions) which is subjected to displacement boundary conditions.
>
> At about 80% true strain, the code stops working and I get the following
> error
>
> "the ratio of deformation speed to wave speed is 1.275 at increment...".
>
> Can restart option with reduced time step be a possible solution?
>
> Is there other ways to tackle the issue.
>
> Thanks in advance
> Brunda
>
>

Re: NODE NUMERATION

2009-11-23T08:39:26Z

This list doesn't allow attachments. You can post the image to a free
server like photobucket.com. The option should be there, and has been
there for several releases, I believe. Perhaps you are using an old
version? Note that you can also try editing your ABAQUS environment
file (abaqus_v6.env) to include the line: case_no_parts_input_file=on.
Alternatively, within the command line interface in CAE you can enter
the command: mdb.models[modelName].setValues(noPartsInputFile=ON).

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

Arane Etxezarreta wrote:

>
>
> Hello Dave!
> That is just what I need, but I dont find the selection that you
> mention. Attached is the image about the edit model attributes box. I
> don´t find "Do not use parts and assemblies in input files", where is it?
>
> Thank you very much, I will save a lot of time with this option.
> Regards
>
> --- El vie, 20/11/09, Dave Lindeman <ddlindeman@...
> <mailto:ddlindeman%40mmm.com>> escribió:
>
> De: Dave Lindeman <ddlindeman@... <mailto:ddlindeman%40mmm.com>>
> Asunto: Re: [Abaqus] NODE NUMERATION
> Para: Abaqus@... <mailto:Abaqus%40yahoogroups.com>
> Fecha: viernes, 20 de noviembre, 2009 22:07
>
> Within CAE go to Model->Edit Attributes->model name, and select the
> checkbox labeled "Do not use parts and assemblies in input files".
>
> Regards,
>
> Dave
>
> -------------------------
> Dave Lindeman
> Lead Research Specialist
> 3M Company
> 3M Center 235-3F-08
> St. Paul, MN 55144
> 651-733-6383
>
> Arane Etxezarreta wrote:
> >
> >
> > Hello to everybody!
> > I need to made a model with part assembly but dependent node numeration.
> > That is to say:
> > By default each mesh starts with a new numeration, so different parts
> > has for example a node number 1,2...(they have coincident node numbers).
> > I need to have different node numbers in the parts. If the part number
> > one last node is the node number 500, the part number two should start
> > with the node number 501. How can I do that???
> > This is very important because I have to modify the input file and I
> > need to have different node numbers in order to do my modification.
> > Thank you!
> >
> > [Non-text portions of this message have been removed]
> >
> >
>
> ------------------------------------
>
> Community email addresses:
> Post message: Abaqus@... <mailto:Abaqus%40yahoogroups.com>
> Subscribe: Abaqus-subscribe@...
> <mailto:Abaqus-subscribe%40yahoogroups.com>
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>
> Shortcut URL to this page:
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> <http://groups.yahoo.com/group/AbaqusYahoo>! Groups Links
>
> [Non-text portions of this message have been removed]
>
>

abaqus user subroutine into obj file

2009-11-23T08:39:24Z

Hi, guys:

I want compile vumat into object file so that it can run in ABAQUS without exposing source code. When I use Intel Fortran to compile the vumat, it always says can't open 'VABA_PARAM.INC.

Does anyone knows how to get around this problem so that I get .o file?

Regards,

Wang

[Non-text portions of this message have been removed]

Re: Too many attempts made for this increment

2009-11-23T08:31:35Z

It means the problem isn't converging (ABAQUS is reducing the time step
size used for an increment repeatedly, but isn't achieving convergence).
You can try:

1) Reducing the initial, minimum, and, possibly, maximum time step sizes
defined on the *STATIC (or *VISCO, or whatever you're using).

2) Increasing the number of cut-backs allowed (*CONTROLS).

3) Using stabilization.

You should take a close look at your *msg and *sta files to see if you
can determine the source of the problem -- for example, is there chatter
in the contact solution (contacts opening and closing), is it having
difficulty achieving convergence in the forces (possible problems with
nonlinear materials), is the displacement increment oscillating or
suddenly increasing (possible buckling instability), etc.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

ariasef wrote:

>
>
>
> Hi dear friends,
> I have made my pile in soil model and I have defined the
> interaction(contact) between them. everything seems to be correct. but when
> I try to submit the job...it says "Too many attempts made for this
> increment" what does it mean? how can I get it fixed?
> please help me...I do need your help.
> Regards,
> Arian.
> --
> View this message in context:
> http://old.nabble.com/Too-many-attempts-made-for-this-increment-tp26421233p26421233.html
> <http://old.nabble.com/Too-many-attempts-made-for-this-increment-tp26421233p26421233.html>
> Sent from the Abaqus Users mailing list archive at Nabble.com.
>
>

Re: Calculating the simulation time for Explicit

2009-11-23T08:24:35Z

If the joint is bolted together, then the two plates should stay in
contact in the overlap region. I would perform the modal analysis
assuming bonded contact at the interface.

You mention that you intend to analyze the joint under tension. This
sounds like a static analysis that should be performed using Standard.
Is the load dynamic, or is there some other reason you intend to use
Explicit?

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

maajidchishti wrote:

>
>
> Dear All,
>
> I am modelling a single lap bolted composite joint under tension. I am
> aware that to calculate the simulation time for explicit analysis we
> have to run frequency analysis.
>
> I saw example in abaqus manual which suggests to remove the contacts,
> surfaces etc from the frequency analysis model and run the frequency
> analysis for the main part of the model.
>
> However, I have some doubts:
>
> My model has two composite plate attached using a bolt. If I follow the
> abaqus example, then I need to delete all the contacts etc. I am not
> sure if that is the correct way to do it?
>
> If I run the frequency analysis for the composite plate which is fixed
> in the model I get very small frequency and therefore very high step
> time. So I not sure if this approach is correct.
>
> It will be great if someone can tell me how should I do frequency
> analysis for my model to find the simulation time.
>
> Thanks in advance.
>
> Regards
>
> Maajid
>
>

Re: Reinforced Concrete Beam-Column Connection: Abaqus Standard

2009-11-23T08:20:03Z

The displacement history can be applied using *BOUNDARY in conjunction
with *AMPLITUDE. The reaction force can be retrieve by requesting
output of the variable "RF" at the appropriate node set.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

Joseph Tan wrote:

>
>
>
> Hi, can i ask how do you apply a displacement history at the tip of
> cantilever and get the corresponding load in Abaqus?
>
> Thank you very much for the reply.
>
> With Regards,
> loo yong
>
> To: Abaqus@... <mailto:Abaqus%40yahoogroups.com>
> From: m.quzhe@... <mailto:m.quzhe%40gmail.com>
> Date: Mon, 23 Nov 2009 08:13:01 +0800
> Subject: Re: Re[ABAQUS] inforced Concrete Beam-Column Connection: Abaqus
> Standard
>
> A better choice is to control the loading by displacement rather than force,
>
> i.e. to apply a displacement history at the tip of your cantilever. This
>
> gives you much better convergency and is also what we actually do in the
>
> experiment.
>
> I believe turn on the NLGeom has nothing to do with your current problem and
>
> will make the convergency evern harder.
>
> A mesh of 0.025m is fine enough for the modeling of concrete and too fine a
>
> mesh will introduce unneseccary damage concentration in your model which may
>
> lead to analysis fail. Try to look into the parameters in you concrete
>
> damaged plasticity model for the reasons of unconvergency. This is usullay a
>
> tricky job. Good luck!
>
> On Wed, Nov 18, 2009 at 2:48 AM, looyong <looyong@...
> <mailto:looyong%40hotmail.com>> wrote:
>
> >
>
> >
>
> >
>
> > Dear all,
>
> >
>
> > I am a graduate student working on my thesis. I am trying to use Abaqus
>
> > Standard to model a RC beam-column connection subjected to a column load
>
> > and
>
> > tip load at the end of the cantilever beam. I am using Concrete Damaged
>
> > Plasticity Model for my concrete and solid beam elements for my
>
> > reinforcement. I am embedding the reinforcement in my concrete.
>
> >
>
> > Using a coarse mesh of 0.1m, static/general procedure, NLgeom OFF, 10
>
> > increment of 0.1sec: Abaqus Standard was able to complete the
> analysis but
>
> > the tip deflection of the beam is very small (0.4mm compared to 6.1mm in
>
> > the
>
> > actual experiment).
>
> >
>
> > So I tried to use a finer mesh of 0.025m element, this time the program
>
> > stops and I have errors of negative eigenvalues and numerical
> singularity.
>
> > I
>
> > tried to change the time step; reviewed and change my boundary conditions
>
> > but the msg still persists. I also turned on NLgeom ON as I think I have
>
> > material non-linearity. I still get the same msg and the program stops
>
> > running.
>
> >
>
> > I will post the input file of my finer mesh (0.025m element) with NLgeom
>
> > ON.
>
> > I really hope someone can offer me advice on how to approach the issues I
>
> > am
>
> > facing.
>
> >
>
> > Appreciate your time to read the post.
>
> >
>
> > Thanks and Regards,
>
> > looyong http://old.nabble.com/file/p26391747/1inchMesh-NLgeom_ON.inp
> <http://old.nabble.com/file/p26391747/1inchMesh-NLgeom_ON.inp>
>
> > 1inchMesh-NLgeom_ON.inp
>
> > --
>
> > View this message in context:
>
> >
> http://old.nabble.com/Reinforced-Concrete-Beam-Column-Connection%3A-Abaqus-Standard-tp26391747p26391747.html
> <http://old.nabble.com/Reinforced-Concrete-Beam-Column-Connection%3A-Abaqus-Standard-tp26391747p26391747.html>
>
> > Sent from the Abaqus Users mailing list archive at Nabble.com.
>
> >
>
> >
>
> >
>
> --
>
> Qu Zhe
>
> -------------------------------
>
> Dept. of Civil Engineering
>
> Tsinghua University
>
> Beijing, 100084
>
> China
>
> --------------------------------------------
>
> http://www.quzhe.net/en.htm <http://www.quzhe.net/en.htm>
>
> [Non-text portions of this message have been removed]
>
>
> __________________________________________________________
> Windows 7: Find the right PC for you. Learn more.
> http://windows.microsoft.com/shop <http://windows.microsoft.com/shop>
>
> [Non-text portions of this message have been removed]
>
>

Re: please help me...I am getting mad with this error

2009-11-23T07:45:45Z

Have you tried using automatic time stepping rather than fixed time
stepping? The error indicates the code can't converge to equilibrium
using the time step size you've defined.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

ariasef wrote:

>
>
>
> Dear Friend http://old.nabble.com/file/p26478993/strip.cae
> <http://old.nabble.com/file/p26478993/strip.cae> strip.cae ,
> My thesis is about pile response to lateral spreading phenomenon. I have
> started learning abaqus since 1 month ago. Now I am trying to simulate one
> strip pile raft footing in clay soil. I have defined surface to surface
> contacts and I don't know why I face with this error:
> "fixed time increment is too large"
> I attached my file.
> for God's sake please help me!
> I really appreciate your taking time to answer me
> Best Regards,
>
> Arian,
> MS student of geotechnical engineering,
> Sharif University of Technology,
> Tehran,Iran.
>
> --
> View this message in context:
> http://old.nabble.com/please-help-me...I-am-getting-mad-with-this-error-tp26478993p26478993.html
> <http://old.nabble.com/please-help-me...I-am-getting-mad-with-this-error-tp26478993p26478993.html>
> Sent from the Abaqus Users mailing list archive at Nabble.com.
>
>

Re: how can I plot complete stress strain curve

2009-11-23T07:26:35Z

The variable LE should give you the total strain.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

Mohammad-Javad Esfandiary wrote:

>
>
> dear friends,
>
> I want to plot stress-strain curve in abaqus for a damage plastic
> concrete.
> I model the concrete. I know that I must use combine() to gain
> stress-estrain curve but in field output I have EE for elastic strain
> and PE for plastic strain. But I want to have i single stress- strain
> curve that I can compare it with exprimental curves.
> in other word, how can I achive complete Stress-strain curve from S-EE
> and S-PE curves?
> regards
>
> [Non-text portions of this message have been removed]
>
>

please help me...I am getting mad with this error

2009-11-23T06:26:08Z

Dear Friendstrip.cae,
My thesis is about pile response to lateral spreading phenomenon. I have started learning abaqus since 1 month ago. Now I am trying to simulate one strip pile raft footing in clay soil. I have defined surface to surface contacts and I don't know why I face with this error:
"fixed time increment is too large"
I attached my file.
for God's sake please help me!
I really appreciate your taking time to answer me
Best Regards,

Arian,
MS student of geotechnical engineering,
Sharif University of Technology,
Tehran,Iran.

Re: RES: Keep nods on the plane during deformation

2009-11-23T04:57:43Z

Another Possibility is to use a Local coordinate system if this plane is not aligned in the Global system and constrain the nodes to translate and rotate only in and about this plane respectively.

Hope this helps.

--- On Sun, 11/22/09, Daniel B. Ferreira <danielbf.ufrj@...> wrote:

From: Daniel B. Ferreira <danielbf.ufrj@...>
Subject: RES: [Abaqus] Keep nods on the plane during deformation
To: Abaqus@...
Date: Sunday, November 22, 2009, 12:33 PM

Take a look at kinematic coupling. It will be better if you read the documentation than if I explain it to you here.

--

Daniel B. Ferreira

Graduation Student on Materials Engineering

Federal University of Rio de Janeiro - UFRJ - Brazil

De: Abaqus@yahoogroups. com [mailto:Abaqus@yahoogroups. com] Em nome de Nan Guofeng
Enviada em: domingo, 22 de novembro de 2009 01:23
Para: Abaqus@yahoogroups. com
Assunto: [Abaqus] Keep nods on the plane during deformation

Dear all,

I have a model and part of itis a plane surface. I want tokeep the elements initially onthis plane remaining on the same plane during the deforming process, but the plane as a whole can rotate or translate, how to achieve this?

Many thanks & kindly regards,
Song J.

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]