Buckling Length Method

muratk

New Member
Hello, I am trying to model the ÇYTHY application guide sample 6.1.B. I can't find the moments and displacements in both the first order and the second order in the example. Where am I making mistakes in modelling? ÇYTHY 6.4.1 b also states that the coefficient of B2 should be 1.5 or less in order to use the buckling length method. How can we control this? At the end of this example, a buckling length is found by the floor stiffness method. Which method is used in the program? Have a nice day
 
Hello there; First of all, if we start with modeling; a- The freedoms you assigned to the node points in the program are not compatible with the figure in the grid. You have 2 different alternatives to harmonize and control quickly. 1- Entering the column foot joint into the columns and modifying this joint to be hinged 2- Selecting the columns, entering their properties with ctrl+e, and editing them to form the joint from the freedoms sub-tab b- In case of reanalysis after the incompatibilities in the modeling are eliminated For example 6.1 in the Guide You can check that the 1st order analysis results for YDKT on pages 21 and 24 match exactly under the fictitious combination. c- 6.4 - Buckling Length Method is used for Stability Design in the program. However, in current version 8.62, the fictitious loads used for second order effects are not calculated automatically by calculating. According to the principles specified in 6.2.2.2, you can define these loads and affect the structure in combination and design the structure. d- As of Version 9, Section 6 of the Steel Structures Regulation - 6.3 - General Analysis Method for Stability Design will be used. General Analysis Method; It is the most inclusive method among the 3 methods in the regulation and can be applied to all steel structures without any limitation. For this reason, thanks to our preferred method, all Steel Structures you produce with ideCAD Steel will be evaluated with the most realistic results. As of version 9, you will be able to examine detailed calculations in accordance with the General Analysis Method. e- With the 6.4 - Buckling Length Method in version 8.62, it can be used in systems where vertical loads are covered by vertical frames, columns and shear walls. In short, it is a suitable method for the structures you produce with the ideCAD Steel program. Due to the lack of calculation of the b2 coefficient in the current version, you cannot see the details about the second order effects. B2 coefficient; In case of using Central and External Braced Support Systems, it is not effective because the system is held in the lateral direction.
 
In this case, as I understand it, it is necessary to switch to version 9 in order to analyze the moment-transmitting frame whose horizontal translation is not prevented, as in the example in the application guide. Because ÇYTHY requires the B2 coefficient to be compared with 1.5 in order to use the buckling length method. In the general analysis method, the problem is solved since the buckling length coefficient is used as 1.0.
 
Hello there; Likewise, it is necessary to switch to version 9 for structures above a certain floor, where second-order effects are important in moment-transmitting frames whose horizontal translation is not restrained.
 
Anyway, the 2016 earthquake regulation has been approved today, it's just a matter of time before it will be published in the official gazette.
 
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