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Materials and Temperature

I got this question from an Engineer today:


How does the NASTRAN NX material library address material temperature? Even if there actually IS a separately named file for each temper and form of each alloy (that’s a lot of files and a lot of complex naming), the reality is still that many of the most important material properties (Elastic Modulus, Shear Modulus, thermal expansion, specific heat, etc) are dependent on temperature.

The answer I am expecting (but would like confirmed) is that any temperature-dependent material property is left empty in the library files. It is up to the analyst to fill-in that data within the model per the needs of their particular analysis. Ergo, any and all materials added to a model from the library become independent from the library once they are added.


I suspect the answer he's expecting would be accurate. Can anyone confirm this?

Thanks
2 REPLIES

Re: Materials and Temperature


"ghayes" wrote in message
news:ghayes.4egxf0@noreply.bbsnotes.ugs.com...
>
> Two questions I got from an Engineer today:
>
>>
>> How does the NASTRAN NX material library address material temperature?
>> Even if there actually IS a separately named file for each temper and
>> form of each alloy (that's a lot of files and a lot of complex naming),
>> the reality is still that many of the most important material properties
>> (Elastic Modulus, Shear Modulus, thermal expansion, specific heat, etc)
>> are dependent on temperature.
>>
>> The answer I am expecting (but would like confirmed) is that any
>> temperature-dependent material property is left empty in the library
>> files. It is up to the analyst to fill-in that data within the model per
>> the needs of their particular analysis. Ergo, any and all materials
>> added to a model from the library become independent from the library
>> once they are added.
>>

>
> I suspect the answer he's expecting would be accurate. Can anyone
> confirm this?
Have you tried contacting GTAC with these questions?
--
John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
John.R.Baker@siemens.com

Re: Materials and Temperature

Hello!,
Well, NX Nastran do not manage any material library, is in NX AdvSim where
you define the material properties. NX includes a library of standard
materials, but you can also create new materials. Most of the materials
included in the NX Material Library comes already with information of
temperature dependency in some properties (you can see by yourself, click on
"Tools > Material" in the *.FEM file).
In NX, you can use fields to define certain material properties as
temperature dependent. If you create an Isotropic material, you can define
properties such as the Young's Modulus or Thermal Expansion Coefficient as
varying with temperature.
If you define any of a material's properties as being temperature dependent
to solve with NX NASTRAN, when you export or solve your model, NX AdvSim
writes out the MATx entry along with the appropriate MATTx and TABLEM1
entries. For example, in a structural analysis, if you create an Orthotropic
material with temperature-dependent properties, the software writes out the
MAT8, MATT8, and TABLEM1 entries to your Nastran input file.
If your model includes temperature dependent materials, you can choose not
to include the temperature dependence in certain solutions. Use the Ignore
Material Temperature Dependence option in the Create Solution dialog box to
ignore the temperature-dependent properties during a solution. With this
option, you do not have to make any modifications to the material itself.
When you select Ignore Material Temperature Dependence, NX does not write
out the MATTx or TABLEM1 entries to export the temperature dependence.
Instead, it evaluates the material's properties at the material's specified
reference temperature, which you define with the Temperature (TREF) option
on the Thermal/Electrical tab of the materials dialog boxes. If you do not
specify a value for the Temperature (TREF) option, NX exports the material
with a reference temperature of 0°.
Best regards,
Blas.
--
~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director
IBERISA
Edificio Ercilla
Rodríguez Arias 23, 3º - Dpto. 19
48011 BILBAO (SPAIN)
Tel. (+34) 94 410 65 50
Fax. (+34) 94 470 26 34
E-mail: info@iberisa.com
WEB: http://www.iberisa.com
"ghayes" escribió en el mensaje de
noticias news:ghayes.4egxf0@noreply.bbsnotes.ugs.com...
>
> Two questions I got from an Engineer today:
>
>>
>> How does the NASTRAN NX material library address material temperature?
>> Even if there actually IS a separately named file for each temper and
>> form of each alloy (that's a lot of files and a lot of complex naming),
>> the reality is still that many of the most important material properties
>> (Elastic Modulus, Shear Modulus, thermal expansion, specific heat, etc)
>> are dependent on temperature.
>>
>> The answer I am expecting (but would like confirmed) is that any
>> temperature-dependent material property is left empty in the library
>> files. It is up to the analyst to fill-in that data within the model per
>> the needs of their particular analysis. Ergo, any and all materials
>> added to a model from the library become independent from the library
>> once they are added.
>>

>
> I suspect the answer he's expecting would be accurate. Can anyone
> confirm this?
>
> Thanks
>
>
> --
> ghayes
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