Head Plate Bolted Joint

M

memorandum

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Greetings, Professor Ruhi Aydın's Steel Structures book in compliance with AISC 360-10 Regulations has a connection example with Bolt and Head plate on page 251. While I was examining this example, I noticed some differences while checking the solution in the program. 1- For the yield strength of the steel column or section 275 mpa rupture 430 mpa (S275), the program only takes the fu value of 0.41 kn/mm2. There is an option to change it, but why does it automatically see 0.41? 2- In general, although the formulas are the same, there are differences in the calculation of the sheet net cross-sectional area (for example, Afn). He said to use the Mn formula, but the program used the Mn formula directly in the calculation. 4-For reference [1] Muir, LS and Hewitt CM (2009). Design of Unstiffened Extended Single-Plate Shear Connections. Considering that you gave Engineering Journal, 2nd Quarter, 67-79, I think that's why there are differences. I could not obtain this publication in pdf or by purchasing. Where can I get the Engineering Journal book? 5-There is a shear and moment load in the combination that the program automatically finds the most unfavorable loading. How can we give the moment and shear force we want to this independent combination? Good work.
 
Hello there; 1- Yield and rupture strengths of steel materials are given within a range in the standards. The minimum breaking strength for S275 is 410 N /mm^2. In the attached image, you can see the yield and tensile strength ranges of steel classes. Therefore, these values can be interfered with in the program. As far as I understand, Ruhi Hoca used an average value. The important thing is to comply with the ranges given by the standards. You can find this table in the resources of IMO or in various textbooks. 2- Plate net cross-sectional areas are calculated in accordance with AISC 360-10. Make sure that the example in the book and the example you created in the program are exactly the same. Since I do not have the book of Ruhi Hoca, I cannot speak clearly, but in the preface they stated that the book includes the changes in the draft regulation of AISC 360-16. If there are some small coefficient differences in the formulas, the results may not match exactly. You can find, compare and manually solve the relevant items in the AISC 360-10 regulation, the results of the combinations have passed the tests successfully. 3- Professor Ruhi gave an explanation about the substance and if you examine the attached AISC 360-10 F13-1 section, the regulation states that there are 2 different situations and if the value expressed with Yt is fy/fu<= 0.8, Yt=1, in the other case Yt= 1.1 If the product of the net area at the tensile head is greater than or equal to the yield strength and the total area of the tensile head, there is no need to calculate Mn, not for Fy/Fu < 0.8, this condition only determines the value of Yt. If you examine the book in detail, there is definitely an explanation beforehand. 4-
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. 5- The program calculates the forces acting on the joint according to its own analysis results. If you want to make it independent, open a new project. If you are going to use this combination again, draw a column and beam and define the combination between them. Then look at the column-beam joint number in the Analysis model structure section. Find the relevant joint no. under the joint point title in the structure tree, select the add joint load with the right button on it, and enter the desired load or moment value. It will be helpful if you follow the attached images 1-6 starting from 1. Good work.
 
Hello, Since I saw the attached values for yield and breaking strength in the 1-Regulation, 430 mpa seems appropriate for breaking. But I think it is correct for 410 mpa min. I had not paid attention before. 2- While calculating the net cross-sectional area of the drawing head, 2025-2*20*16.2 = 1312 mm 2 is taken in the book. Afn = 1247.4 mm 2 in the program. Can you give a brief explanation of how you got this value? I think it is 2025- 2*24*16.2=1247.4 mm 2, but why is d= 24 mm? 3- Since the values in Afn and fu are different, the book did not calculate Mn because it was larger than fu*Afn>yt*fy*Afg in the book, I misunderstood when I was asking myself. Thanks to İdeçelik, our horizons have been opened. control is good. Thanks again for your attention. Good work.
 
Hello there; 2- Anet calculations are made with effective hole diameters as per the regulation. The attached images contain information about how the account is made and the standards. Good work.
 
Hi, The point I want to draw attention to is Afn=Drawing head calculating the net cross-sectional area, d=24 mm for M20, d=26 mm for M22, d= 29 mm for M24, d= 32 mm for M27, d= 35 mm for M30. It does not accept d+2 or d+3. good work.
 
Hello there; I guess you didn't review the image named bolts. If we explain with an example, bolt diameter db= 20 mm, standard bolt diameter db+2 mm =22 mm, de=dh+2 mm = 24 mm for M20 bolt. For this reason, in the example you created, M20 8.8 bolt is used in the calculation and Afn=24 mm is used in the calculation. The same is true for the bolts you type in the other order. If you wish, you can also review the New Turkish Steel Regulation. The same situation and tables are available.
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Good work.
 
db, bolt diameter dh, hole diameter de, effective hole diameter (AISC 360 stipulates that the bolt hole should be taken as dh+2 mm when calculating the net area. This is because the hole wall may be damaged while drilling the bolt hole. See attached image) In your example, for M20 bolt : db = 20 mm, dh = db+2 = 22 mm, de = dh+2 = 24 mm.
 
Greetings, Ms. Nurgül, Mr. Emre, 1-Which unit we work with in the calculation of Sheet Bending Buckling, the results of this part appear as ksi and in 2-Support Welding strength calculation w= weld arm length varies according to the weld thickness. What is the source, document that you can guide to calculate this? 3-We have calculations such as px, py, and eccentric in the beam bolt slip calculation (in the tutorial), but what do we use them for and what are your suggestions for calculation logic? good work
 
Hello there; 1- The error has been noted. 2- Weld thickness (a) = weld arm length (w) * 0.707. The visual figure explains why it is multiplied by a coefficient of approximately 0.707. 3-
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, especially Chapter 7 simple combinations, Chapter 8 Eccentric Joints will clear many question marks in your mind. Other than that
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If you search for the combinations you want to get information from FEMA's site, you can find many documents. Good work.
 
Hello, a few additions to what Ms. Nurgül wrote: 1-Metric units will be written in the Plate Bending Buckling calculation starting from version 8.505. If you look at the reference document provided, when calculating lambda, the original formula used "ksi" for tension and "in" for length (as you know, imperial units are used in the United States). When we convert these to N/mm² and mm, the coefficient 0.381 precedes the original formula. 2-You enter the fillet weld thickness while modeling the joint (since weld thickness is generally used in our country). The weld arm length is used in the calculation (as it is in the literature). Nurgül Hanım explained how the two would be transformed into each other. 3-In the joint design options, you can choose one of two methods for bolt shear calculation (instantaneous center of rotation and elastic method). Both methods take into account eccentricity (eccentricity effect). Elastic method is a more known and preferred method because it is easier to calculate. In this method, it is considered that the stress-strain relationship of the bolts is linear (elastic) and the yield stress is not exceeded. However, at the instantaneous center of rotation, the nonlinear stress-strain relationship is defined based on experiments and the strength of the bolts is calculated with some empirical formulas. You can find detailed information about these calculation methods in the AISC Design Manual 14th edition, in addition to the references given by Ms. Nurgül. Although the regulations are tried to be written comprehensively and clearly, we engineers may need helpful books that explain them with examples. In this context, I recommend the following resources for the design of elements and calculation of combinations according to AISC 360-10 and New Turkish Steel Regulations: William T. Segui, Steel Design 5th Edition Louis F. Geschwindner, Unified Design of Steel Structures 2nd Edition
 
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