Notion load factor for 0.002 or 0.003

RE: Notion load factor for 0.002 or 0.003

淵鈞張 — Thu, 22 Jun 2017 01:24:46 GMT

hello Sye ,

very very thank you about your answer again and again.

Regarding the matter that you taught me as shown below.

answer of 3.

Your pdf shows reactions for load cases 141, 143, 101 etc.

--->

actually I selected the load case from 101 to 243,

and check the max values, but no any effects in the results.

You need to add notional load to cases as appropriate and then check the results.

--->

ok , I will try to do this again, really thank you very much.

very very
thank you and appreciated.

RE: Notion load factor for 0.002 or 0.003

淵鈞張 — Thu, 22 Jun 2017 00:54:40 GMT

hello Sye ,

very very thank you about your answer again and again.

a few of queries still remain.

When I specifying the notional load , and which direction should be applied in staad ?

for example , moment frame or braced frame.

Is any specific rule for these ?

sometimes I heard about

"" Ni is not applied when the actual lateral load is larger than the calculated notional load.""

but in AISC360-16 , I can not find this kind of specification, I thought that is the specification of AISC360-05 or 10.

do you have any idea about that ?

very very
thank you and appreciated.

RE: Notion load factor for 0.002 or 0.003

Sye — Thu, 22 Jun 2017 00:10:42 GMT

1. I chose load 208 randomly just to explain how the notional load generation works. You need to choose appropriate load cases.
2. Correct
3. Your pdf shows reactions for load cases 141, 143, 101 etc. I had just included the notional load for case 208 and so these reactions will not be affected by what I did. You need to add notional load to cases as appropriate and then check the results.

RE: Notion load factor for 0.002 or 0.003

淵鈞張 — Wed, 21 Jun 2017 05:06:06 GMT

hello Sye ,

very very thank you about your assistance again.

very sorry , I still have some queries that need your help and advice.

"A notional load is a lateral load (horizontal load) which is derived from an
existing vertical load case."

according to this concept , and you use the load case 208, is that right?

(load case 208 is carried about primary vertical load)

because , in the beginning I have no idea why you choose load case 208.

(load case 208 is bundle pulling for maintenance)

"Multiple load items can be specified under any NOTIONAL LOAD and there can be
one or more blocks of NOTIONAL LOAD command(s) in any load case."

as this rule, I can also add the blocks of notional load in load case 209 to 211

or other load case that carried about primary vertical load.

do I right ?

About Result

I`ve run the staad and compare the result of reactions.

I found the reactions are the same , there are noting changed in staad result.

Or there are other way to verify the result ?

I attached the results, does anything that I make mistake ?

very very
thank you and appreciated.

RE: Notion load factor for 0.002 or 0.003

Sye — Tue, 20 Jun 2017 17:40:43 GMT

Regarding 1, in Direct Analysis the Taub values are determined iteratively based on the axial force in the member. When you set the notional load factor to 0.003 these iterations are not carried out and Taub is considered as 1 which is what the code recommends.

Regarding 2, Added the notional load in X direction for your load case 208. Modified file attached communities.bentley.com/.../Notional_5F00_load_5F00_0003_5F00_syntax_5F00_modified.STD

Regarding 3, the direct analysis implementation in STAAD automatically handles that. There is nothing additional that you have to do.

RE: Notion load factor for 0.002 or 0.003

淵鈞張 — Tue, 20 Jun 2017 03:39:15 GMT

hello
Sye , very very thank you about your assistance.

I still have some questions.
Sye `s answer as shown below , and I wrote my queries as well.

1. Correct.
--->
I read some technical reference and it is said :

***f3 = Notional Load Factor. Default is 0.002. If 0.003 or greater is
entered, then τb will be set to 1.0 and no iterations will be performed.
and
***If f3 is greater than 0.00299, the program sets the iteration limit to 1
and does not perform any additional iterations.

no iterations will be performed <--- what will happen in my staad results ?
and what is the meaning of "does not perform any additional iterations or no iterations will be performed"

2. What you specified is correct but in addition, you need to add the notional loads too. More details in the wiki below
--->
yes , I tried to do that way, but I just got the command of NOTIONAL LOAD FACTOR 0.0 in my staad.
I am very sorry , I will send my staad data for you , could you please teach me how to add the notional loads in my staad.
I need to know what I am doing the correct command in staad.

3.
The purpose of direct analysis :
***Reduce Axial & Flexure stiffness to 80% for members selected in the Define
***Direct input. The 80% applies only to analysis.*****

Is any way can make sure that in my staad ? or I need to write some syntax in staad ?

very very
thank you and appreciated.

RE: Notion load factor for 0.002 or 0.003

淵鈞張 — Tue, 20 Jun 2017 03:37:41 GMT

hello
Sye , very very thank you about your assistance.

I still have some questions.
Sye `s answer as shown below , and I wrote my queries as well.

1. Correct.
--->
I read some technical reference and it is said :

***f3 = Notional Load Factor. Default is 0.002. If 0.003 or greater is
entered, then τb will be set to 1.0 and no iterations will be performed.
and
***If f3 is greater than 0.00299, the program sets the iteration limit to 1
and does not perform any additional iterations.

no iterations will be performed <--- what will happen in my staad results ?
and what is the meaning of "does not perform any additional iterations or no iterations will be performed"

2. What you specified is correct but in addition, you need to add the notional loads too. More details in the wiki below
--->
yes , I tried to do that way, but I just got the command of NOTIONAL LOAD FACTOR 0.0 in my staad.
I am very sorry , I will send my staad data for you , could you please teach me how to add the notional loads in my staad.
I need to know what I am doing the correct command in staad.

3.
The purpose of direct analysis :
***Reduce Axial & Flexure stiffness to 80% for members selected in the Define
***Direct input. The 80% applies only to analysis.*****

Is any way can make sure that in my staad ? or I need to write some syntax in staad ?

very very
thank you and appreciated.

RE: Notion load factor for 0.002 or 0.003

Sye — Tue, 20 Jun 2017 03:02:06 GMT

1. Correct.
2. What you specified is correct but in addition, you need to add the notional loads too. More details in the wiki below
communities.bentley.com/.../20964.does-specifying-the-notional-load-factor-as-0-002-automatically-define-notional-loads