Steel cross slenderness problem

I

inansas

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Hello there; Although I tried large sections, I could not overcome the slenderness problem. Am I making a mistake somewhere, I would appreciate it if you could help me
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Hello there; Sub-title slenderness problem appears on the scissors. To solve this problem, you need to use stability beams that pass through the middle joints of the subheads. Stability beams support your truss sub-heads in the lateral direction and reduce the buckling length in the lateral direction. The link to the previous training on solving the fragility problems is below, please check it out.
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Good work.
 
I'm already using the solution you mentioned for the subtitle. I forgot to write it was about the crosses that I actually asked. I am stuck with the slenderness criterion even though I enlarge the cross sections too much
 
Hello there; Stability beams were not modeled in the model you sent and there was a slenderness problem in the bottom of the truss, you stated that you know the solution. The situation in the crosses is the same, naturally the solution logic is the same. The slenderness formula is k*l/r where k is 1 and constant for braces, l is the net span of the element, and r is the radius of inertia of the section. According to our steel regulation, k*l/r should be less than 200 for pressure elements, while it should be less than 300 for tension elements. Considering the formula, you can identify alternatives for the solution. Even if your braces do not have problems in strength control, you have to meet the slenderness condition of the Steel Regulation. Good work.
 
Hello, there are cross members in my project that do not provide strength and slenderness control in cross design controls. how can i overcome this problem? and why don't they show up in the analysis report? I would be very happy if you would review the project in the example and let me know if you have any suggestions. Good work
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Hello there; There are 2 problems with your modelling. 1- Do not divide the beams from the area that fits the column. You can divide it at a suitable place in the opening and connect it by using the lap plate joint joint or the face plate joint. 2- If you choose the first and the last beam, not the purlins separately for each span, there will be no overlap in the joints. Divide at all intersections with the divide command. The items mentioned above have been applied to your project. To solve the problem in your diagonals, you should either shorten the cross section or increase the cross section. Good work.
 
I have one more question. Are stability beams needed on inner axles in the y direction? I was undecided whether or not to throw it away. If discarded, should these beams be attached to columns or IPEs? Or are crosses sufficient? If thrown will it help with the diagonal problem? Thank you, good work.
 
In order for the load flow in the system to be appropriate and to ensure the continuity of the structure, the columns should be connected to each other with beams on the inner axes. This addition will not solve your cross slenderness problem. The important thing is that the system works properly, which ensures that the beams to be added.
 
Have a nice day teacher. I cannot overcome the slenderness problem of the braces even though I have increased the stability beam, the number of braces and the diagonal profile dimensions. There are 2 different roofs, I made different applications to see the k*l/r difference, but I still couldn't get a very serious slenderness result. This project is my first project to be implemented, I would like you to see it, your ideas are very important to me, but I could not send it because the file size is large.
 
When my teacher enlarged the cross sections a little too much, the slenderness decreased below 200, but now the lovers have exceeded the deflection limit. I drew 2 projects of the same type, I did not encounter deflection with a smaller purlin cross section, but I got stuck on the truss lower cap strength. 2 projects are in the link. I would be very happy if you share both the source of the problems and your opinion about the project. If you can return early, it would be greatly appreciated, I have to deliver the project tomorrow. Good work
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Hello there; There is a problem with your model. After the analysis, it is necessary to check whether the structure behaves as expected in the vertical loads and modal results from the deformations sub-tab in the perspective screen analysis view. It looks like your diagonals are not attached to the scissors. I think you cloned in that region. Re-enter the diagonals. Pay attention to the high wall thickness of the cross sections you will use. Another solution for slenderness would be to reduce the size, you can try using 4 instead of 3 in a clearing. After the modeling errors are eliminated, start the control with the deformations after the analysis.
 
Thank you sir for your information. While defining the diagonals, I reduced the nodal points by 1, but when I used a cross section smaller than 114.3*3, I still encountered a slenderness problem. naturally, I defined the cross node points as 2 to get rid of the excess cost. I don't see any problem in the analysis right now. There is no problem in the account reports, but the purlin sections are not comfortable for me. They are defined as 60*120*4 - 5 mm and I think they are very large in cross-section. Is there any way I can lower the love sections? I do the bide crosses without cloning, but sometimes the junction points disappear by themselves, what is the reason? I have one last question. I put one end of my truss on the heb180 beams, which I defined with a gusseted joint on the curtains. How much can I trust this design?
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Hello there; If you enter the lovers in one piece, there is no problem. Since there are 3 openings, the analysis results become more positive in the gerber beam logic. You can use it this way. In order to make the scissors safer, you can try to connect the lower and upper heads separately to the curtain. For this, you need to remove the cover of the scissors, for your information.
 
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