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simulating bimetallic effect

Creator
Creator

hello,

 

i want to simulate the bending because of different expansions of two materials which are connected with screws. But I've no idea how to do this with nx (which solver etc).

 

I calculated the elongation of the two materials and the amount of bending like here:

 

 

https://www.youtube.com/watch?v=131WPhKnFsA

 

 

the elongation was about 0,09 mm and the amount of bending about 0,11

 

I applied an enforced load on the ends of the two rails (0,05 left and 0,05 mm right) and fixed the girder with a few nodes in the middle (backside).

 

furthermore i connected the rails with a face gluing contact

 

clipboard-hp7440d4ubf[1].jpg

 

the bending in the result was also about 0,1 mm

 

clipboard-p10212nnu4n[1].jpg

 

 

but as mentioned above, i want to simulate it with temperature (delta T = 20K / alpha1=6 / alpha2 = 12). In the material properties i entered the thermal expansion coefficient, E-module, density and poissons ratio.

 

any suggestions how to proceed?

 

thanks in advance

2 REPLIES

Re: simulating bimetallic effect

Siemens Phenom Siemens Phenom
Siemens Phenom

If the materials have been defined appropriately (with different thermal expansion coefficients), then all you need to do is apply a uniform temperature difference.

 

In SOL 101 (linear statics), create an initial temperature with an appropriate default temperature (i.e. 20C). Create a temperature load with a different default temperature (i.e. 100C).

 

The solution will compute the expansion for a delta T of 80C.

Re: simulating bimetallic effect

Creator
Creator

tank you! This was easier than expected.

 

btw: I got a warning message because of the glueing connection

 

Unbenannt.png

 

dunno why :-/ edit: found it: https://community.plm.automation.siemens.com/t5/NX-Nastran-Forum/What-does-USER-WARNING-MESSAGE-4690...

 

 

is it practical to use this kind of connection (glue connection) to simulate the screw joints?

 

Its the only way the rails dont slide, even when I use surface contact with friction coefficient 5 and 7000N force to push the rail on the girder