Hello, I´m designing a reinforced concrete "perimetral wall" (Not really sure that´s the name it would have in English) that has 2 different sections, the only change between sections is that one has a 30 x 40 cm "tie beam" (again,not sure that´s the name) and the other one a 25 x 90 cm tie beam. So my problem is this: when I check displacements at the top of the columns for one model I get 22.673 mm and for the 2nd model I get a max displacement of 25.43 mm wich I believe is a pretty big difference given the similarities. I´ve tried to make sense of this difference but haven´t been able to. If someone could point me in the right direction I´´d apreciate it. Here are both models. And if you see anything funny in the models apart from that feel free to let me know, any advice is good advice for me. Thanks in advance.
CERCA 2D SE PEONIAS.std CERCA 2E2 SE PEONIAS.std
Dear User,
I have some quick observation regarding your models. Though the models look similar but there are some basic differences as listed below.
1. The total height of the structures differs. In one model height of column is 4.875 & in other it is 5.025m.
2. As you have changed the size of the tie beam, the stiffness of both the models become different.
3. The total applied load (vertical & lateral) for different primary cases also differs which can be seen from output.
From the above point it is very clear that there will be obvious difference in deflection values. Please let me know if you have any more doubts.
Thanks for the reply, I understand the first two observations and I agree with you. However I´m not completely clear on that last one, the lateral loading of the structures should be the same, I get that the vertical is different from selfweight and also different load values but the wind loads are applied in the same way and with the same values for both models, or am I missing something in regards to this last part?
If you run both the files in output it prints the value of total applied load for every load case. Please go through it and you will find the difference. I am attaching 2 screen shots for reference.
This difference is due to the change of sizes for the tie beams & height of the structure. You may check the same.
Ok now I get it, thanks a lot for your help.