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Interpolation - Stress Strain Curves

Hi,

I am trying to do a Simulation for a Plastic intake manifold subjected to different temperatures for Analysis. I have the stress strain values at 120°C and 150°C respectively from the material supplier. However I am interested in calculating at 130°C. Does anyone know how to key in so that the optistruct can interpolate at 130°C. Thanks in advance for your replies.

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Rahul Rajan_21763

Do you want to carry thermal stress analysis?

Rahul Rajan_21763

Please find attached .fem deck using Optistruct solver.Tables1 & Tablest for temperature dependent stress strain curves.

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Altair Forum User

Thanks for the attachment Rahul. I tried the same considering your model, however I came across following error no. 3012. I have attached the screenshot below. Awaiting for your reply?

<?xml version="1.0" encoding="UTF-8"?>

Rahul Rajan_21763

Looks like error is because of Tables1 enteries.How many enteries you have in Tables1 card?

Altair Forum User

Thanks for the reply. I have 12 entries in each tables. I have attached the screenshot below. Everything is in the ascending order but couldn't figure out the error.

Rahul Rajan_21763

Could you share us out file & if possible share .fem file aswell.

Altair Forum User

Hi. I have shared the .out files .

Rahul Rajan_21763

Could share screenshot of Tables1 enteries?

Rahul Rajan_21763

Also you have defined total strain or plastic strain?

Altair Forum User

I have defined plastic strain

Altair Forum User

Screenshot of tables1 entries

<?xml version="1.0" encoding="UTF-8"?>

Rahul Rajan_21763

Remove 0 in X & Y enteries and run.

Rahul Rajan_21763

I mean start curve from .0025 & 7.25.

Altair Forum User

I did but comes the error doesnt satisfy Zero non Zero requirement. I changed the typstrain to off so as to avoid conflict but doesn't work either.

Rahul Rajan_21763

Did you refer the deck which i have shared?

Altair Forum User

Of course I did but seems there is some other Problem which leads to error. I have one question from your fem model, the value of Limit1 as 100 because I don´t see the Initial yield Point as 100 in the tables which you have used. Thanks.

Rahul Rajan_21763

OS considers only those value given in the TABLEM1, TABLES1 and TABLEST values.Please share us the error you are currently getting.

Altair Forum User

I used MATT1 for temperature dependent material and the Simulation did run this time without any Errors. Thanks for your promt replies.

Rahul Rajan_21763

Thanks for the update.

Diogo Torrão

"I have the stress strain values at 120°C and 150°C respectively from the material supplier. However I am interested in calculating at 130°C. Does anyone know how to key in so that the optistruct can interpolate at 130°C."

Thats also a question that I have on my head. I have multiple material curves for different temperatures but, as obviously, temperature varies across the part I am studying. How the solver chooses the correct curve to apply if there are temperatures between the temperatures used to define the curves ?

Maybe you can explain that.

Thanks in advance.