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Calculation of Kz, Ky, Ly and Lz
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PTHVKM7
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PostPosted: Sun Jul 22, 2018 9:30 am    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

Better understanding of Flexural unsupported length will get from bending moment diagram. The sign is changing from possitive to negative near ridge because it is compression ridge. So flexural unsupported length will become half span.


See attachment





-- Original message --
From: srinivasan_vasudevan <forum@sefindia.org>
Date: 22/07/2018 12:10 (GMT+05:30)
To: general@sefindia.org
Subject: [SEFI] Re: Calculation of Kz, Ky, Ly and Lz

     If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as the length .

Vasudevan




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org)> wrote:

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tanpriti
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PostPosted: Sun Jul 22, 2018 12:30 pm    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

Hi Vasudevan,


25m is correct. If you draw the deflected shape you will see the reason.  

Regards,



Tanmay Biswas  BCE, MSc, CEng, PEng, FIE




From: srinivasan_vasudevan <forum@sefindia.org>
Sent: 22 July 2018 12:40 AM
To: general@sefindia.org
Subject: [SEFI] Re: Calculation of Kz, Ky, Ly and Lz  

If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as the length .

Vasudevan




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org)> wrote:

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srinivasan_vasudevan
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PostPosted: Sun Jul 22, 2018 5:30 pm    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

Hi agree that 25 mts span is correct 

Vasudevan 




On Sun, Jul 22, 2018, 10:12 PM pankaj.gupta <forum@sefindia.org (forum@sefindia.org)> wrote:

Quote:
           Ly should not be 1.5 but distance between the braced nodes. UNL can be 1.5
Lz is ok at 25 m if there is a moment connection at the ridge.

Sent from my iPhone

On 22-Jul-2018, at 12:10 PM, srinivasan_vasudevan forum@sefindia.org (forum@sefindia.org))> wrote:


Quote:
           If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as the length .

Vasudevan




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org (forum@sefindia.org) (forum@sefindia.org (forum@sefindia.org)))> wrote:

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krane
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PostPosted: Sun Jul 22, 2018 6:30 pm    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

Well he is not talking about out of plane bending. He is talking about in plane bending (Lz). In gable type frames, low slope up to 1 in 30, ridge point can suitably considered as support point, therefore Lz can be considered as 25m. 

50m would be very conservative approach. 

Regards, 
K K Rane 


On Sun, Jul 22, 2018 at 12:10 PM, srinivasan_vasudevan <forum@sefindia.org (forum@sefindia.org)> wrote:
[quote]            If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as  the length .

Vasudevan 




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org (forum@sefindia.org))> wrote:

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Fahim_Pathan
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PostPosted: Sun Jul 22, 2018 7:30 pm    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

I want to learn the design of peb shade pls give me any reference or any lead will be appreciated.

On Sun 22 Jul, 2018, 10:08 PM tanpriti, <forum@sefindia.org (forum@sefindia.org)> wrote:

Quote:
           Hi Vasudevan,


25m is correct. If you draw the deflected shape you will see the reason.

Regards,



Tanmay Biswas BCE, MSc, CEng, PEng, FIE




From: srinivasan_vasudevan
Sent: 22 July 2018 12:40 AM
To: general@sefindia.org (general@sefindia.org)
Subject: [SEFI] Re: Calculation of Kz, Ky, Ly and Lz

If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as the length .

Vasudevan




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org (forum@sefindia.org))> wrote:

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sktrisal
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PostPosted: Mon Jul 23, 2018 12:30 am    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

it sounds funny that we have lost the capacity to design a50m truss without Stad.i think it is shameful and the continuous debate ever so


On Sun, 22 Jul 2018, 22:08 tanpriti, <forum@sefindia.org (forum@sefindia.org)> wrote:

Quote:
           Hi Vasudevan,


25m is correct. If you draw the deflected shape you will see the reason.

Regards,



Tanmay Biswas BCE, MSc, CEng, PEng, FIE




From: srinivasan_vasudevan
Sent: 22 July 2018 12:40 AM
To: general@sefindia.org (general@sefindia.org)
Subject: [SEFI] Re: Calculation of Kz, Ky, Ly and Lz

If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as the length .

Vasudevan




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org (forum@sefindia.org))> wrote:

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sathiyaseelann
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PostPosted: Mon Jul 23, 2018 1:30 am    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

Dear all,  The following is not w.r.t stadium but conceptwise


If the flexural torsional buckling  is the concern, then 25mtrs will result in huge section I suppose so we can use purlin spacing  as lz through flange bracing provision. Because, it is the LTB governs the flexural design so distance between the flange bracing can be used for flexural design about major axis. For minor axis, no issue since there is all through support via roofing. 
If anything wrong, please correct me. 


Thanks. 



On Jul 22, 2018 12:12 PM, "srinivasan_vasudevan" <forum@sefindia.org (forum@sefindia.org)> wrote:[quote]            If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as  the length .

Vasudevan 




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org (forum@sefindia.org))> wrote:

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SATYAPAUL
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PostPosted: Mon Jul 23, 2018 2:30 am    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

in my opinion Lz shall be 25 M.CROWN OF PORTAL FRAME SHALL BE CONSIDERED AS NODE SUPPORT.BUT when  calculating strength of rafter i.e design Lz shall be 25M.because half span i.e rafter is fixed at  crown.PLEASE SOLVE THE STRUCTURE ON PRINCIPLES OF STRUCTURAL ANALYSIS.FIND THE MOMENTS AND STRESSES AT  EACH NODE POINT.THE PICTURE WILL BE CLEAR.PLEASE REFER PAGE 450 TO 459 OF BOOK"STRUCTURAL DESIGN IN  STEEL" BY SALWAR ALAM RAZ PRINTED BY NEW AGE INTERNATIONAL(P) LIMITED PUBLISHER. REGARDS SATYA PAL   On Sun, 22 Jul 2018 14:59:36 +0530 "srinivasan_vasudevan"  wrote >                   If the roof profile is of Gable type with a ridge at the centre , then with a tie member of  sufficient stiffness , the out of plane bending can be considered with 25 mts as  the length . >  > Vasudevan  >  >  >  >  > On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry wrote: >  >       --auto removed--

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sathiyaseelann
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PostPosted: Mon Jul 23, 2018 3:30 am    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

Dear all, It's staad not stadium... Typo error.... 


On Jul 23, 2018 6:55 AM, "Sathiya Seelan" <sathiyaseelann.s@gmail.com (sathiyaseelann.s@gmail.com)> wrote:[quote]Dear all,  The following is not w.r.t stadium but conceptwise


If the flexural torsional buckling  is the concern, then 25mtrs will result in huge section I suppose so we can use purlin spacing  as lz through flange bracing provision. Because, it is the LTB governs the flexural design so distance between the flange bracing can be used for flexural design about major axis. For minor axis, no issue since there is all through support via roofing. 
If anything wrong, please correct me. 


Thanks. 



On Jul 22, 2018 12:12 PM, "srinivasan_vasudevan" <forum@sefindia.org (forum@sefindia.org)> wrote:[quote]            If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as  the length .

Vasudevan 




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org (forum@sefindia.org))> wrote:

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hemraj chanchal
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PostPosted: Mon Jul 23, 2018 8:30 am    Post subject: Calculation of Kz, Ky, Ly and Lz Reply with quote

Dear vasudevan
Ly Can be consider 1.2m but distance between the braced nodes. UNL can be 1.5m
Lz is ok at 25 m if there is a moment connection at the ridge.Also you can consider 1.2m
distance is safe.

Hemraj Chanchal
BSc(physics), MTech(structure)
M/S. HC construction & Consulting Engineers Pvt. Ltd.




On 22 July 2018 at 12:10, srinivasan_vasudevan <forum@sefindia.org (forum@sefindia.org)> wrote:
[quote]            If the roof profile is of Gable type with a ridge at the centre , then with a tie member of sufficient stiffness , the out of plane bending can be considered with 25 mts as  the length .

Vasudevan 




On Fri, Jul 20, 2018, 12:33 AM Kalpesh Mistry forum@sefindia.org (forum@sefindia.org))> wrote:

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