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Tensile Test MAT25

Altair Forum User

Hello,

I'm trying to create a simple model of a tensile test for composite material. I have data from a real tensile test and i want to compare the data of the force/strain diagramm with the simulation model. To realise that i tried to read the output data of the nodes with the /TH/NODE card for die displacement and the /TH/SECT card for die forces. My problem is that i don't get any data for the forces in the T01 file. The Question is now: Is my defintion for the cross section incorrecton?

Greetings

Eugen

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Altair Forum User

Hi Eugen,

Please share the model file (_0000.rad) so that we can review the defined cross section.

Altair Forum User

Hello George,

here is the .rad data.

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Altair Forum User

Hi Eugen,

The imposed velocity load is not assigned to any node groups. Please reassign the imposed velocity load and check.

Altair Forum User

Hello George,

i fixed it, but still i dont get any results from the th/sectio outputblock. In the .out data there are only rows wtih 0 and it says that no nodes are connected to the section ( start at row 629, Im opening the files with the Programm Notepad++)

Do I have to to set a GNODS for the definiton of the Crosssetction?

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Altair Forum User

Hi Eugen,

There is no need to define GRNOD set also.

Please find a simple model with a cross section defined.

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Altair Forum User

Hello George,

how you defined the Crosssection excatly? I tried it my self with an axe system wich i defined by nodes und a group of elements. But i still dont get any results. I looked in the output file and there a no nodes connected:

Your Crosssection:

SECTION 1 ID 1
---------------
TYPE . . . . . . . . . . . . . . . 0
FILENAME . . . . . . . . . . . . .
DELTAT . . . . . . . . . . . . . . 0.000000000000
ALPHA. . . . . . . . . . . . . . . 0.000000000000
FRAME TYPE . . . . . . . . . . . . 0
NUMBER OF INTERFACES . . . . . . . 0
INTERFACES:

NUMBER OF NODES. . . . . . . . . . 26
NODES:
450 447 419 451 458 284 459 500 497 501
509 508 510 693 690 657 694 702 701 703
747 744 748 756 755 757

NUMBER OF BRICK ELEMENTS . . . . . 0
BRICK N1 N2 N3 N4 N5 N6 N7 N8

NUMBER OF QUAD ELEMENTS . . . . . 0
QUAD N1 N2 N3 N4

NUMBER OF SHELL ELEMENTS . . . . . 25
SHELL N1 N2 N3 N4
161 1 0 0 1
163 1 0 0 1
164 1 0 0 1
176 1 0 0 1
178 1 0 0 1
179 1 0 0 1
226 1 0 0 1
229 1 0 0 1
241 1 0 0 1
242 1 0 0 1
245 1 0 0 1
246 1 0 0 1
436 1 0 0 1
438 1 0 0 1
439 1 0 0 1
451 1 0 0 1
455 1 0 0 1
456 1 0 0 1
506 1 0 0 1
508 1 0 0 1
509 1 0 0 1
521 1 0 0 1
522 1 0 0 1
525 1 0 0 1
526 1 0 0 1

NUMBER OF TRUSS ELEMENTS . . . . . 0
TRUSS N1 N2

NUMBER OF BEAM ELEMENTS . . . . . 0
BEAM N1 N2

NUMBER OF SPRING ELEMENTS . . . . . 0
SPRING N1 N2

NUMBER OF 3 NODES SHELL ELEMENTS . 0
SHELL N1 N2 N3

________________________________________________________________________________________

My Crosssection:

SECTION 2 ID 2
---------------
TYPE . . . . . . . . . . . . . . . 0
FILENAME . . . . . . . . . . . . .
DELTAT . . . . . . . . . . . . . . 0.000000000000
ALPHA. . . . . . . . . . . . . . . 0.000000000000
FRAME TYPE . . . . . . . . . . . . 0
NUMBER OF INTERFACES . . . . . . . 0
INTERFACES:

NUMBER OF NODES. . . . . . . . . . 0
NODES:

NUMBER OF BRICK ELEMENTS . . . . . 0
BRICK N1 N2 N3 N4 N5 N6 N7 N8

NUMBER OF QUAD ELEMENTS . . . . . 0
QUAD N1 N2 N3 N4

NUMBER OF SHELL ELEMENTS . . . . . 0
SHELL N1 N2 N3 N4

NUMBER OF TRUSS ELEMENTS . . . . . 0
TRUSS N1 N2

NUMBER OF BEAM ELEMENTS . . . . . 0
BEAM N1 N2

NUMBER OF SPRING ELEMENTS . . . . . 0
SPRING N1 N2

NUMBER OF 3 NODES SHELL ELEMENTS . 0
SHELL N1 N2 N3
SUMMARY OF POSSIBLE INCOMPATIBLE KINEMATIC CONDITIONS :
-----------------------------------------------------

NO TRUE INCOMPATIBLE KINEMATIC CONDITION

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Altair Forum User

Hi Eugen,

Create an element set (/GRSHEL/SHEL) and recall the same in the grshel_ID option in crosssection card. In Frame_ID option, recall the system you have created.

Please review the model I've sent before.

Altair Forum User

Hello George,

after some adjustments on the model i finaly got a workin simulation with the data i want. But the results dont match with the real tests.

Now i want to check if my inputs for the material data is incorrect or the mat law i choosed is not compatible. To do that i want to simplify the model. First to cut the elements to only 13 and set the same conditions before. The problems is that i get an error 760 and i dont know how to handle it. Here are the Error and the model file:

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Altair Forum User

Hi Eugen,

The component in the model is not assigned with any property or material. Assign Part card image to the component and assign the material and property and try running the analysis.

I m sorry I have to realize tensile test analysis for cfrp composite specimen how to obtain load - displacement and stress - strain curve

I modeled 1/4 of composite specimen

I uploaded .rad file

I dont know force output displacement output stress and strain output

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Altair Forum User

Hi,

By creating time history output for elements it is possible to output stress and strain for the elements.

Go to Analysis>Output Block> elements, select elements. Card edit the created output block and change the keyword accordingly. Use DEF keywprd to output the default outputs.

Please go through the Help Menu on Output Blocks which describes about the various outputs available in Time History.

Also please go through ths webiniat at https://www.youtube.com/watch?v=Ef7Spn-j7fA&list=PL1u26y75SCrA_BOCLaSewVCNY7xRvCTnA&index=6 which describes about creating output blocks.

Using cross plot option you can crate load-displacement curves...etc. The steps for cross plotting is shown in an example file below. Please go through the documents attached.

Unable to find an attachment - read this blog

Hi,

By creating time history output for elements it is possible to output stress and strain for the elements.

Go to Analysis>Output Block> elements, select elements. Card edit the created output block and change the keyword accordingly. Use DEF keywprd to output the default outputs.

Please go through the Help Menu on Output Blocks which describes about the various outputs available in Time History.

Also please go through ths webiniat at https://www.youtube.com/watch?v=Ef7Spn-j7fA&list=PL1u26y75SCrA_BOCLaSewVCNY7xRvCTnA&index=6 which describes about creating output blocks.

Using cross plot option you can crate load-displacement curves...etc. The steps for cross plotting is shown in an example file below. Please go through the documents attached.

in hypergraph, which file, I have to open? (.h3d, .out or t01) for plot

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Altair Forum User

Hi,

Open the T01 file in HyperGraph for plotting the curves.

when I defined a crossection I recieve only force output but not stress, strain or displacement

I want to recieve stress strain and displacement output how to realize?

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Altair Forum User

Hi,

I'm attaching a sample similar model where these options are used. I recommend you to go through the files.

In HyperView we have an option, build plots panel which allows user to construct multiple curves. User has to select the required element and using this option plots can be created.

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in time history output for shell, F1 F2 variable are force or stress?

Altair Forum User

Hi,

Please go through the Help Menu on /TH/SHEL which explains about Time History output variables for Shell Elements.

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I have looked at this table however

when modelling of composite, I can obtain true stress in second direction (F2) why?

how to define or change fiber direction ?

Altair Forum User

Hi,

Please go through Composite Properties topic in the Help Menu where different modeling methods for composites are explained, which includes defining plies where user can specify different material direction.

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I cannot get strain data however I can stress data where stress datas are f1 or f2 right?

how to get strain data?

Altair Forum User

Hi,

You can input /ANIM/SHELL/TENS/STRAIN/N, where N is the layer number (eg:/ANIM/SHELL/TENS/STRAIN/1 for strain in layer 1), keyword in the engine file for extracting strain for each ply.

ok, thanks

however how to obtain strain data for HYPERGRAPH

Altair Forum User

Hi,

You can create an output block for the elements and the time history output include plastic strains, strain rate...etc

Hi George,

while defining the cross section.What is the purpose of grnod_id (node group identifier), What these nodes do with results?

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Altair Forum User

Hi Karthic,

In HyperMesh, when crosssection is defined user has to create a set for the elements and also a node set which should be recalled here.

Hi George,

set for the elements and also a node set which should be recalled here.

So the node set contains the nodes that belong to the elements of element set?? I am correct

And how to create System with FRAME/MOV, FRAME/MOV2 ????

The system which i create is always FRAME/Fix by default.

so once when i select the system in /SECT, i am getting a message that ' Selected entity fails filter: Filter by system type/FRAME/MOV

Altair Forum User

Hi Karthic,

Yes Karthic, even I think you can create the section without creating node set.

For FRAME/MOV, select the card edit option and select the system created and select FRAME type option.

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Thankyou George

Hello,

I actually had a question about the output requests of RADIOSS solver 2018. I want to see 1). the changes in the fiber orientation and 2). % Thinning as outputs after running stamping simulations using MAT LAW 25 and Stack Prop 51. Currently, I am unable to see these outputs in Hyperview 2017.3. I am aware that these results are solved for in case of MAT 58 which is a Fabric law but are these outputs not available in case of MAT 25?

Thanks in advance!

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