Polygon Columns...

M

Mirza

Member
Mr. Levent Özpak... The ductility level is mixed in a selected structure; Is it normal that a polygon column (Alphas) does not contribute to the calculation? In the design made as a polygon column, there is a frame whose alphas value is less than 0.40 in the direction of the major axis of the polygon (in the Y direction) (think of the polygon column here as L-shaped, 200/55/25 dimensions), which is closed by two symmetrical polygons in this way, but in the alphas calculation it is 0, 40 value cannot be exceeded (Alphas y=0.27)... Second case; When we delete the polygons without interfering with the other curtains of the project, replace them with two curtains of 200/25 size, and perform the analysis, the Alphas Y value exceeds 0.40... Question: Can't the program detect the polygon as a curtain? In the column application plan, (200/55/25) polygons hurt like columns.... the drawing part is not very important, but I wonder if there is a defect or a pro in the calculation part of the program? Or are we misinterpreting? Even if it's a polygon, shouldn't the calculation of a curtain element be done like a curtain, that is, the ratio of shear forces (Alphas ratio)? I am waiting for your comments and suggestions... thank you in advance for your interest and wish you success in your work...
 
Merabalar, unfortunately, there is no definition of polygon curtain in the v5 version we use. In order for your L or U type curtain shapes you want to enter to be included in the "alpha"s calculations, each arm must be entered as a separate panel. You include it in "alpha"s accounts and you also receive your expansions as curtains. however, you need to combine the expansions and correct the header areas and stirrup lengths in 2d drawings. at the end you will get the opening of each bar separately in the printouts. You need to change the stirrup sizes according to the way you enter the project. In v6 dada there is currently no change related to this issue. Secondly, I know that there is a lot of work at the moment for column application in v6. We talked to our programmer friends that in future versions, LU or other types of curtains will be given ready-made in the drawings. In this way, this type of curtains will be able to be entered more easily and directly reflected in the account, and we will not waste time due to corrections during the drawing stage. I wish you good work.
 
Hello there; Friends, if we want polygon columns to be included in the alpha s calculation in V5 and V6, we should check the P box at the end of the relevant line under the Reinforced Concrete/Column heading and perform analysis. I am attaching a picture related to the subject, I hope it will be useful. I know that this kind of polygon columns are being studied to make them like curtains in the drawing. Especially for elevator curtains, such drawing details are needed.
 
I didn't know that you had to click the p button to add it to the alfas account. Thank you for your information. however, it is not enough to just join the alfas account. Such curtains should be taken as curtains in the drawings. As a result, it meets the curtain requirement even if it is in a polygon due to its length of l. Therefore, it must have head and middle regions. Therefore, it is necessary to enter all the arms in the form of panels and make corrections in the drawings. When you enter the pitch as a polygon column, I think the program does not take the arms into account separately. However, it is necessary to effect all arms separately in x and y directions. Except for the calculation, when the curtain system is entered as a column in the drawings, we get a drawing consisting of a single heading instead of headings (3 or more headings are required because it is a polygon) and middle regions. The accuracy of this is debatable. good work.
 
Thank you for your interest and comments... fixed, if we do as you say, our polygon screen is participating in the alpha calculations as far as I understand? Now I want to ask one more question... (L/b>=7), the regulation says it will be equipped as a curtain. Question: An element with a width-to-width ratio in the plan is less than 7, for example, a ratio of 5~7... Would it be wrong to equip this element in accordance with the curtain reinforcement arrangement rules? Then, as you said, if we mark P from the Reinforced Concrete/Column tab, will this element be included in the Alphas calculation for the mentioned element (for example: 25/150 curtain-column)? I'm also waiting for comments on this, is it wrong? Thanks in advance for your comments and shares...
 
For example, let it be a type l polygon curtain, one arm of it is 100, the other arm is 100 and the thickness of both arms is 25. Now, since these arms do not provide the ratio of 1-7 one by one, the program does not define them as a head. In these cases, I enter both arms as panels. Thus, it enters the alfas calculations and participates in the calculations in both branches separately. As for the drawings, since the program does not define a title in the drawings and gives it like a normal panel, I draw caps on the end points and intersection points, change the reinforcements and stirrups, under the conditions specified in the regulation, different from rigid floors and non-rigid floors. In the colon application, I combine both branches and add them to the plan. It's a little troublesome, but I guess that's the way it is. As Levent said, the program will do it in future versions without us having to do it.
 
"...these arms are a curtain with a total length of 200 L and a thickness of 25 providing a ratio of 1-7." would the expression be correct? As far as I know, shear walls are defined as the ratio of the length in the direction of earthquake impact to the width of the body, and as far as I understand from what you said, the plan lengths of the polygonal curtains you designed in the direction of each earthquake are 100 cm and their bodies are 25 cm. It does not need to have the necessary equipment arrangements. (end region, body region...etc) while the regulation sets limits for curtains, if L/b>=7, some conditions have run... If our carrier (L/b =4 like the project in your hand) is below this rate, Curtain design conditions can not apply has not brought a limitation. Would it be wrong to recognize and model this type of carriers as curtain-columns? How accurate would it be to ignore the contribution of these carriers to the AlfaS calculation? For example, if the minimum screen size is 25/175, it contributes to Alfas, but a vertical carrier with 25/170 does not contribute, how consistent is this approach? *As for the program part of the work. If we choose the dimensions 25/175 from the Column tab, we introduce curtains and there is no problem in the calculations. In fact, whatever the length in the plan, the panel elements contribute to this account. I hope I am not misunderstood, the purpose is not to question, but to learn by sharing... thanks for your suggestions and sharing, success in your studies... *Note: It is not my place to comment on the program, I apologize to the connoisseurs. However, I tried to explain what I know, if I made a wrong or incomplete comment. I seek your indulgence...
 
To explain the program's assumptions about the screen: If your element is entered as a rectangular column and the L/b ratio is greater than 7, the program considers it as a panel, equips it and adds it to the alphas calculation. If your element is entered as a rectangular column and the L/b ratio is less than 7, the program considers it as a column and does not do anything about the panels. If you enter it as a 2-point panel element, it will consider it as a panel regardless of the L/b ratio and add it to the alphas calculation. (Whether or not the head reinforcement is made depends on whether the element is a critical panel and the regulation conditions. Head reinforcement is not created for those with L/b ratio less than 7.). If you enter the polygon as a column and tick the p box as Sabit Bey said in the reinforced concrete dialog, the shear force contribution is taken into account in the alphas calculation even though the polygon is equipped as a column. Here, only the columns with l/b>=7 are treated like panels, because it is more practical to enter some geometries with a column (single-point element) and to allow the panels to be defined with "elements entered as columns".
 
I agree with Mr Mirza's approach. Just as a column with L/b>7 transforms into a panel and contributes to the alpha s value, and if the regulation foresees a ratio of 1/7 for this contribution, shouldn't it be considered as a column in a 25/50 panel element with 1/2 ratio and modeled as a panel? ?? (Bo forum has become a milestone in my opinion; if the user-programmer interaction continues like this, the program will quickly be able to respond to our dreams.)
 
First of all, I wish everyone a happy new year. After reading your articles, I went through some books for these l and u type curtains and asked someone who I believed to know the subject well and as far as I understood; Article 3.6.1.1 of the regulation states that "curtains are vertical structural elements with a ratio of at least 7 to the thickness of their long side in plan". here he does not say anything about L and U type curtains. it just says something about the ratio of the long side to the thickness. What the regulation says about polygon curtains is not very descriptive. As I wrote above, I was looking at the total length of L. As a result of my research today, there is a conviction that this is partly true, rather false. like this. For example, a L-type 150*150*25 vertical liver (not 100*100*25, each arm is closer to the curtain) looking at the alphas is >0.4, so if we are not going to switch our system from ductile to mixed, there is no harm in entering curtains. or if all the carriers are going to decrease R to 7 because we entered a column and R while we were entering 8, it would be wrong to enter a polygon column, but it would be best not to enter them as a polygon column and not add them to alfas. This is a bit contradictory to what I wrote before, but (I was looking at the total length L anyway), I am thinking of creating the system as a polygon column from now on, as long as it does not provide the 1-7 ratio of at least 1 arm. I'm waiting for the ideas of my fellow programmers on this subject... As for why the 170*25 dimensions Syn Mirza said are very close to the screen, but why it does not participate in the calculation of alfas, yes, it is very close to the screen. In the past, they even accepted 25*150 as curtains (I don't remember, but the old designers say) but the fact is that the whole system is designed according to certain assumptions and the behavior of the building is tried to be predicted. 1-7 is an acceptance and 1-69 is very close to 1-7. I think it would be wrong to think whether it should be considered a curtain, because according to someone else, the ratio of 1-5 is a close ratio. I wish you good work....
 
Mr. Fixed, First of all, I wish you a happy new year... I hope that the subject we discuss here is not limited to Ide's solutions and approaches, let's continue to discuss engineering... Now, as you said, the rate of 1/5 compared to others is more According to another, 1/4 ratio may be considered close, maybe you are right. It is a relative situation after all... However, I think there is a gap in the boundaries of whether a vertical bearing element is a curtain or a column... Namely; for columns defined as bxh>=25x30... (b: short side, h: long side) for walls, defined as L/b>=7... for columns the ratio of long side to short side (h/ b) Is there a maximum limit value in the regulations? (I couldn't find it, if anyone knows, please help us, I would be grateful if they could tell us which regulation it is in...) However, there is a recommended value for this limit. Some of our professors say that this value (h/b) should not exceed 3 ~ 3.5... the main question arises here by itself... how do we approach the elements above this limit value but also below the 1/7 ratio? Curtain pattern, ratio less than 1/7. If you look at it as a column, the h/b ratio is greater than 3.5... (weak column, buckling problem, slenderness... etc.) Elements whose contribution to the limitation of the relative storey drifts cannot be neglected can be said to be almost as effective as the curtain... I think that there is a gap. In my opinion, the regulation approaches with very sharp rules and a straight (Aristotelian Logic) logic "either you have a curtain or a column"... well, is there any in-between? can't it? In my opinion, approaching the event with Fuzzy Logic will lead to more flexible solutions. For example, choosing the Ductility level as Karma; While it limits the relative storey drifts in the lower floors in curtain walled structures, these offsets increase as one goes to the upper floors... In framed structures; While the relative displacements on the lower floors are very high, these displacements towards the upper floors decrease. This approach underlies the fact that the mixed system is both an economical and flexible solution. We do not limit the event with sharp lines, we do not say High or Normal ductile. We said; Let my high ductile shears work on the lower floors, limit the displacements, on the upper floors my curtains are weak against the displacements, so Normal ductile columns should come into play, limit the offsets and the construction should be flexible and economical... I think that such an approach should be added to the regulations regarding the elements mentioned. Thank you for your patience... Best regards...
 
You must log in or register to reply here.
Back
Top