Symmetry in finite element

[Sadeq]

Hello,

Please help my question is really basic,but i need help


I have concrete box and steel box and bolt as illustrated in picture one(quarter shape),so my questions are:

the key points in symmetry for the quarter of the shape are:
1.prevent translation in the two plan direction(allow translation in the direction vertical to the shape)
2.prevent rotation in the three directions or what( this is exactly my question, i believe i have to prevent rotation in the three direction, or maybe only around the the two axis(plan axis, not the vertical )
3. do i need to apply those conditions at the all section boundary for example steel and concrete and etc .
4. apply quarter of the load (right?)


The second question is in picture 2,the area in which i pointed here demonstrate that the bolt here is smaller than the steel(in perimeter,so don't match exactly, and concrete show up, so do i need to apply conditions on this small area

Note this area will represent only gap in the real situation see picture 3 pls

http://img35.imageshack.us/img35/1336/47179197.png
http://imageshack.us/photo/my-images/189/15136950.png/
http://imageshack.us/photo/my-images/853/66361611.png/

 

[Valkarie]

Thanks in advance. In order to answer your questions, it is important to first understand what type of structure or material you are dealing with and how it needs to be secured. In the case of the concrete box and steel box, it is likely that the two need to be bolted together with some sort of fasteners. If this is the case, then the key points for symmetry for the quarter shape would be to ensure that the bolts are evenly spaced and that the bolts are strong enough to hold the two materials securely together. Additionally, the bolts should be placed in such a way that there is no rotation or translation of either material when the bolts are tightened. Finally, you would need to apply force along the entire perimeter of the shape in order to fully secure the two materials together. Regarding the small area pointed out in picture 2, if it is a gap between the steel and concrete, then it is likely that you will need to fill the gap with some sort of fastener. This could be a thin piece of metal, a special epoxy, or some other material that can effectively fill the gap while still providing a secure bond between the two materials.