Automate an option of effective length and effective length factors for Steel as well as RCC structures

-->Summary of effective length factors for steel & RCC columns as per Indian codes as below:--> 1: Annexure-D , clause: 7.2.2 of IS 800-2007 (Ky & Kz of steel columns) 2: clause 8.3 (Table-15) of IS 800-2007 (Kx). 3: Annexure D-2.1 & D-3 of IS 800-2007 (Ky & Kz for stepped columns) 4: Annexure-E , clause 25.2 of IS 456-2000 (Ky & Kz of RCC columns). -->Refer following snaps, all of above requirements should be implemented as mentioned in a single revision like other softwares, so that deliverables of staad pro software can be enhanced.

The feature of automatic effective length factor ky and Kz has implemented, but effective length factor for lateral torsional buckling (Kx) or LLT has not been implemented till now, it strongly needs to implement as per clause 8.3 and table 15 of IS 800 2007 code.

Automatic effective length factor calculation is almost completed for all code, including annexure D-1 D-2 of IS 800:2007 . Now it is the nice time to implement automatic effective length factor calculation for RCC columns/members, particularly as per Annexure E of IS 456:2000.

Staad pro takes node to node distance for member design as Ly and Lz , irrespective of inspecting whether member break in any of its direction or not, this member length value true for one of the axis but may be incorrect for other direction,this problem need to resolved in staad.

Automatic Effective length/ effective length factor of RCC/steel column should be incorporated as below . 1- For RCC structure, Annexure- E of Code IS:456 2000, 2- For steel structure, Annexure-D of code IS:800 2007 & Annexure D-1 and D-2 of IS 800:2007

Effective length factor Ky and Kz should also be incorporated for "single stepped" or "double stepped" columns, as per Indian code IS: 800 2007 annexure : D-2 & D-3.

Thank you, we are adding this idea for adding a tool to calculate effective length of steel members to the product backlog. If this proves well adopted, then we will lok to expand with an option for concrete members.

Dear All,

With reference to the above constraint in calculating the KZ parameter for Moment Resisting Frames, a Macro has been developed.

This macro is aimed at..

1. Minimum manual inputs to Macro, which shall minimized the calculation checking efforts of engineer.

2. User is only responsible for correct modelling of staad file. Thus the checking efforts are limited to staad input file. Minimal efforts are then required to verify that the correct inputs are entered on to the Macro screen.

3. User shall initiate a design of Moment resisting sway frame by assuming KZ parameters (May be by approximating the end conditions with the standard diagrams given in code).

4. Once the preliminary section sizes are determined the exact KZ parameters can be entered which the Macro calculates in automised way.

5. The Lengths and Section properties are taken from Staad file itself and no manual efforts are required.

Since all (Most of the inputs) the required inputs are obtained from Staad file itself, a similar approach can be adopted in staad engine and this way the user intervention can be completely eliminated to achieve both accuracy and Saving of time and efforts.

Users, please note that the attached macro is prepared considering the requirements/formulae as per Eurocode National Annex - Nedelands.

Similar Macro can be developed for other codes as well.

The detailed video for "how to use" the macro & flowchart can be viewed at below links

https://www.youtube.com/watch?v=QfMJcA2wiAA&t=12s

https://www.youtube.com/@CivilBotsforBeginners/featured

Regards,

Pravin Agashe.

Thank you for posting your idea. I hope you dont mind, but I have added the description based on your comment as you didnt do that when posting it. There has been requests for having some form of automation provided for defining the effective length factors, but there are different rules for different codes and in different countries. What are the rules that you are advocating? How would the expect the program to know how the rules should be applied? Is the starting point determining the physical object and then where restraint points are ion the model. On steel structures that often means providing some information about the connection type. Is the connection to the web or one/both flanges, etc. That is currently not part of the analytical model so much more information would need to be added to the analytical model before using automation rules.

Sir For steel structures,when we are going to assign the Design parameters especially Ly,Ly,Lz and kx,ky,kz , we have to give much manual efforts ,like first we have to identify member length, it's end conditions etc..then we apply effective length and it's factors,it is to be applied for each and every members,it is very tedious,time consuming and error prone process,inspite of giving such efforts,the applied factors like 1.5,2,.65 etc is not accurate but it is approximate values, we want an automate option for Lx,Ly,Lz and Kx,ky,kz in staad pro CE as per members end conditions. Moreover for RCC structures there is also much more manual efforts for applying ELY,ELZ parameters for each and every beams and ELY,ELZ,ky,kz for columns, though RCDC automatically calculates effective length and it's factors,but we want this automatic option in staad pro CE ,rather moving towards RCDC,kindly add this feature in upcoming version of Staad pro CE.thanks...