Problem with DFF command not check in steel design with STAAD Pro SS6 built 20071150 (Latest built)

What different of command?.
LOAD LIST 101 TO 107 and LOAD LIST ENVELOPE 1
which Envelope 1 include load no. 101 to 107 ?
I remember that I ever use this command in SS4 without define any envelope.
STAAD can check code and check the deflection.

Does it's mean in the SS6 we must define and evelope for check deflection limit

and for steel design code check we must define envelope or not for the correct result ?.

With most of my code only use LOAD LIST ... TO ... command.

Regard.

I check about load list command with or without ENVELOPE.
When I use code check command without deflection check as below
....
LOAD LIST ENVELOPE 1
PARAMETER 1
CODE AISC UNIFIED 2005
METHODE ASD 
CHECK CODE ALL
...
There are no result from steel design code check.
but if use
....
LOAD LIST 101 TO 107
PARAMETER 1
CODE AISC UNIFIED 2005
METHODE ASD
CHECK CODE ALL

...
There are stress ratio results from steel design check.

and for the deflection check
....
LOAD LIST ENVELOPE 1
PARAMETER 1
CODE AISC UNIFIED 2005
METHODE ASD 
DFF 240 MEM .....
CHECK CODE ALL
...
There are results from steel design code check of member with have DFF assign.
but for member without DFF there are no result.

This is an improvement? I think this make user confuse to use ENVELOPE or LIST and go backward.
For the member that need code check both stress ratio and deflection we must check code 2 times?
1 time for deflection only and another for stress ratio and which one controlled the design?


Regard.

** I add "METHODE ASD" to clear my question.

There has been an update in the program to specifically impel the users to create two different type of envelops- Service and Strength to cater two different aspect of design- deflection checking with Service Envelop and member design using Strength Envelop. This provides a clear vision on design aspect.

You need to create two different envelops- one for strength and another for service. Service load envelop is to be used for deflection check and Strength load envelops are to be used for member design where you will find the stress checking.

Please have a look into the following:

communities.bentley.com/.../92764

communities.bentley.com/.../23987.serviceability-and-strength-check-for-the-same-load-combination

You need to create two different envelops- one for strength and another for service. Service load envelop is to be used for deflection check and Strength load envelops are to be used for member design where you will find the stress checking.

Please have a look into the following:

communities.bentley.com/.../92764

communities.bentley.com/.../23987.serviceability-and-strength-check-for-the-same-load-combination

I have attached a modified file with SERVICE and STRENGTH envelopes which has subsequently been used to do a CODE CHECK.

Here are some points which should be noted.

1. For both service and strength and checks to be carried out, you have to have 2 separate envelopes. In the attached model, you will find 2 separate envelopes namely service ( cases 101 to 107 ) and strength ( cases 201 to 207 ).

2. The LOAD LIST ENV 1 2 has been used just before the design so that the design accounts for both envelopes during design.

3. DFF has to be specified as part of the design parameters if deflection check is to be carried out. This is in addition to defining the service envelope. Since you specified DFF for members 3 10 and 13, the deflection check will be carried out for these members only. If you need to check other members for deflection, specify DFF for those too.

4. Since you need the same combos to be checked for service and strength (ASD), you need to add the combos 201 to 207 which are basically same load combos as 101 to 107 but still needed as STAAD.Pro cannot consider same load combos for both service and strength envelopes.

I hope this helps.

2330.Structure1_rev.std

Hi all,
Im using SS6 20.07.11.70 version. I used DFF and service envelope in my design. But still it is not performing deflection check.

I have clearly defined service envelope then why STAAD showing the below warning.

**WARNING- Deflection check of member # 4 will not be performed as service envelope not provided.

Here is the code.

STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 07-Apr-16
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 5 0 0; 3 0 3 0; 4 5 3 0; 5 0 0 3; 6 5 0 3; 7 0 3 3; 8 5 3 3;
MEMBER INCIDENCES
1 1 3; 2 2 4; 3 3 4; 4 3 7; 5 4 8; 6 5 7; 7 6 8; 8 7 8;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 2.05e+008
POISSON 0.3
DENSITY 76.8195
ALPHA 1.2e-005
DAMP 0.03
TYPE STEEL
STRENGTH FY 253200 FU 407800 RY 1.5 RT 1.2
END DEFINE MATERIAL
MEMBER PROPERTY EUROPEAN
1 TO 8 TABLE ST IPE500
CONSTANTS
MATERIAL STEEL ALL
*
SUPPORTS
1 2 5 6 PINNED
*
LOAD 1 LOADTYPE Dead TITLE LOAD CASE 1
SELFWEIGHT Y -1
LOAD 2 LOADTYPE Live TITLE LOAD CASE 2
MEMBER LOAD
3 TO 5 8 CON GY -50
LOAD COMB 3 GENERATED AISC GENERAL 1
1 1.0
LOAD COMB 4 GENERATED AISC GENERAL 2
1 1.0 2 1.0
LOAD COMB 5 GENERATED AISC GENERAL 3
1 1.0 2 0.75
LOAD COMB 6 GENERATED AISC GENERAL 4
1 0.6
PERFORM ANALYSIS
*
DEFINE ENVELOPE
1 3 TO 6 ENVELOPE 1 TYPE SERVICEABILITY
1 3 TO 6 ENVELOPE 2 TYPE STRESS
END DEFINE ENVELOPE
*
LOAD LIST ENV 1 2
*
PARAMETER 1
CODE AISC UNIFIED 2005
DFF 500 MEMB 3 TO 5 8
FYLD 248213 MEMB 3 TO 5 8
FU 413688 MEMB 3 TO 5 8
CHECK CODE MEMB 3 TO 5 8
FINISH

You have created Service and Strength envelop with the same load case / combination. Please refer to the attached model.

2465.a1.std