About Analysis Time and Semi/Full Rigid

A

AtalayKivanc

New Member
Good day . We have been trying to complete the attached unfinished project for some time . However, when the size of the project is added to the fact that the analysis time is too long, it causes great trouble for us. I have a few questions about this subject 1.) In which situations should we choose semi-rigid or fully rigid flooring? If we have chosen semi-rigid slab, do we have to choose the option to consider earthquake effects in slab design? Can a fully rigid selection be made in this project? 2.) Semi-rigid - Analysis time exceeds 100 minutes including earthquake effects. Is there an option to reduce this time? (Analysis time at full rigid is 25 minutes) (i7 - 3.6 ghz - 8 gb ram) 3.) We are analyzing using Ritz method, do you think this is the right choice, can we change the number of modes in the Ritz method? 4.) There are some parts of my mind about the shutter ratio control. In the 2007 regulation, Curtain Ratio was called for systems with 'curtain only' carrier system. In the 2018 regulation, the phrase 'only' in the curtain ratio section was removed and the carrier system was arranged as curtains. Do I need to consider the screen ratio calculation control in this project? Because the file was large, I was able to download it via wetransfer [url=https://wetransfer.com/downloads/b965f8789f55644b6c0fbb3b11ea739720190712094013/7b8d62cefc263ba34469d91f53868f8720190712094013/f84aatransferl...
 
Good day , I can not solve the questions in my mind , I would be glad if you could help I changed the finite element width, the analysis got relatively short. But my questions in the theory part continue. Good work
 
Hello there; 1) The semi-rigid diaphragm solution is the closest to reality. In the semi-rigid diaphragm solution, the slabs are modeled with shell finite elements. In the rigid diaphragm solution, on the other hand, it is assumed that the in-plane stresses of the floors are small and the structure moves as a whole on the floor basis. The semi-rigid diaphragm solution can be chosen for any type of structure. The assumption of a fully rigid diaphragm can be made when certain floors are of sufficient thickness and there are no gaps in the floors. According to TBDY 2018 Article 4.5.6.3, it says that full rigid diaphragm can be accepted in regular structures in the plan where there is no A2 and A3 irregularity. Apart from this, it does not allow the acceptance of a rigid diaphragm in non-beamed floors. If I give a little more detail, since the floors are modeled with shell finite elements in the semi-rigid diaphragm solution, the stiffness of the floors are solved together with the structure. For this reason, the effects of the floors can be seen in the full sense. If in-plane stresses occur in floors due to earthquakes, you can only see this with a semi-rigid diaphragm solution. Since the rigid diaphragm is accepted as the assumption that the slabs do not receive stress for the plane, the in-plane deformations (hence the stresses) are zero and this means that the in-plane effects of the slabs are canceled. If the rigid diaphragm acceptance and the semi-rigid diaphragm solution are close to each other (this occurs in buildings without A2 and A3 irregularities), a rigid diaphragm can be assumed. Checking the option to consider earthquake effects in slab design will give you serious advantages in terms of slab stress controls. In the semi-rigid solution, the design you make according to the earthquake effects will be the closest solution to the reality. 2) You can make your preliminary design as a rigid diaphragm to reduce analysis time. After determining your sections, you can solve the final analysis as a semi-rigid diaphragm. Another reason why your analysis time is long is that it is a building with a basement. Apart from this, our work on accelerating continues. 3) The analysis with the Ritz method is a type of modal analysis, just like the analysis of eigen vectors. As in your project, ritz and eigen vector solutions will not make a difference in structures containing only reinforced concrete elements, as they give the same results. You can change the mod number in the "modal analysis" section of the build tree. 4) TBDY 2018 has given a ratio in Article 7.6.1.3 for buildings whose carrier system consists of shear walls. However, since your project is curtain and frame, you do not need to consider this control. The main control that should be done about the curtains is the overturning moment control. Best regards...
 
Good afternoon Mr. Oguzcan, Thank you very much for your valuable answers. We were having some problems with the municipalities, especially regarding my 1st question. That part was important to us, it was pretty self explanatory. Good work.
 
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