Learning Forum

[Erik Brendel]

Hello,

in my mechanical Model i need to take expansion of concrete into consideration and also the thermal expansion through hot and cold temperature. But at first I modelled the expansion of concrete, that happens because of the ingredients of it. I took it into account with a body temperature, afterwards I added also the thermal expansion, but it collides. The whole model consists of granite, sandstone, concrete and everything has a body temperature and the concrete also needs to get the expansion in every dimension through the expansion reaction. Is it possible to consider this in Ansys?

The green marked solid needs both expansions (through temperature and through the chemical reaction).

Any help is appreciated.

Thanks in advance!

Erik

[dlooman]

This is a difficult analysis to do accurately because some of the chemical heating during curing occurs before the concrete has its full strength.  If I understand you, you want to do a second thermal analysis of the concrete after it is cured, but temperature load were already applied in the initial analysis of curing.  One idea is to separate the two analyses.  You do a separate analysis of the curing and write the stresses to file.ist by issuing INISTATE,WRITE before the solve.  Then in a completely separate analysis you read those initial stresses with INISTATE,READ and apply the in service thermal loads.  

[Erik Brendel]

See below my answer, forgot tobdo this as reply

[Erik Brendel]

We have a static system that is changed much through an unwanted chemical reaction in the concrete 50 years after building it, so the concrete has ITS strength, so now I want to have results where the changed system through unwanted Expansion of the concrete and the normal temperature is included. The Expansion of concrete ist about 50 to 200K compared to the other parts and I need to consider that the building is Like 40 degree Celsius in top and 30 in bottom. I don't know If this helps. Thanks in advance.

[dlooman]

It might not be possible, but if you want to use thermal strain to simulate the effect of the unwanted chemical reaction you can do it in a separate analysis as I described before.  Before solving in the first analysis you issue INISTATE,WRITE.  This will write the stresses to a file name file.ist.  Then in a completely new analysis you can issue INISTATE,READ to read those stresses into the 2nd analysis and input the 40/30  deg temperature.

[Erik Brendel]

Okay, is this enough, wenn I use this command: inistate, write, 1, , , , ,s !  in the first model and INISTATE,READ, file, ist, 'path' in the second one? This only exports and imports stresses, right? In the end, is there any difference when I do this with strains?

[dlooman]

Yes, when I used this procedure to model curing concrete I just wrote the stresses as you show above, not the strains.