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Author Topic: Generalized shell export: temperature-dependence  (Read 37106 times)

JanPio

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Generalized shell export: temperature-dependence
« on: June 13, 2018, 11:25:23 AM »
Hi,
we use ANSYS with HFEA and I noticed that the ASEC-beams, RECT-beams and SHELL-sections in the updated "..._i.cdb" have pointers on their respective material definitions, which are temperature-dependent (MPTEMP, MPDATA).
The GENS-shells, however, seem to have only one set of material properties. That means that all the shell elements of the updated FE-model will not have temperature-dependent material properties in the next analysis.
  • The properties of which temperature are used to calculate the generalized shell properties written to the new ANSYS file?
  • GENS-shells in ANSYS can actually have up to 6 different sets of mat-properties by reentering the SSPA, SSPD etc commands for different temperatures. Is there an option in HS to use this?
Thanks,
Jan

Stephen

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Re: Generalized shell export: temperature-dependence
« Reply #1 on: June 13, 2018, 12:30:37 PM »
Hi Jan,

You are correct that we are outputting a single set of generalized shell properties to the FEM when iterating with HyperFEA.

1. HyperSizer outputs properties corresponding to the temperature of the controlling loadcase for that component.
2. At this time, we do not support multiple sets of material properties for a single section in the FEM. If this changes in the future, we will be sure to state so in the update notes.

Let me know if you have any other questions!

-Stephen

JanPio

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Re: Generalized shell export: temperature-dependence
« Reply #2 on: June 14, 2018, 01:31:13 AM »
Hi Stephen,
thanks so far, this answered my questions.
Regarding your answer #2 my doubt is the following:
actually you do support this already for all the beam and layered/continuous shell sections (SECTYPE,...,SHELL) by exporting the temperature table MPTEMP,...,TEMP1,TEMP2,etc. This could lead to errors, e.g. the shell section has a constant Young's modulus for all temperatures while the adjacent beam changes stiffness or thermal expansion coefficient with varying temperature. Additional "phantom stress" would occur.

Jan

Stephen

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Re: Generalized shell export: temperature-dependence
« Reply #3 on: June 22, 2018, 09:51:06 AM »
Hi Jan,

You are correct that we do indeed export temperature-dependent properties to ANSYS for composite shells and bars. Unfortunately I do not have an immediate solution for you on this, but I have discussed with our developers and we will try to address it in a future release.

For now, one possible option is iterating with a single set of properties (copy materials and remove all but one temperature), before doing a final analysis and sizing cycle with the temperature-dependent properties.

Thanks,
Stephen