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

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

Sye — Fri, 27 May 2016 17:37:28 GMT

We investigated the issue and found a bug that is causing the incorrect deflection check in this case. This has been logged with id# 460624 and will be fixed in the release of STAAD.Pro SS6 SP3 coming out at the end of June 2016.

As a temporary workaround, for the second set of design in your file dealing with serviceability, you may use the CODE AISC instead of the CODE AISC UNIFIED which would invoke the AISC 9th edition code for checking the deflection. As far as deflection checking is concerned, it should be the same for both codes. However we are getting the issue addressed in the AISC 360 UNIFIED code with top priority.

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

Sye — Fri, 27 May 2016 00:20:40 GMT

I do agree that the member should fail. I am looking into why it is not and will revert back shortly.

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

kannan as — Thu, 26 May 2016 11:51:35 GMT

Hi,

Please refer to the attached staad file. For example take Beam #133 (T-Support) the deflection ratio is very less. but if you check the relative deflection its huge. Can you please check and revert why its happening. Sometimes when I run the file its shows the failure due to deflection fot the T-support. Request you to update the status ASAP.communities.bentley.com/.../Sample.std

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

Sye — Thu, 12 May 2016 17:29:59 GMT

Ok sure. Will do. Also just wanted to inform you that whenever we release a new version of STAAD.Pro, the news is published in the STAAD News section that you see when you start up STAAD.Pro as shown next

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

kannan as — Thu, 12 May 2016 03:46:52 GMT

Thanks sye. Appreciate your reply in this regards. I would like to request you to inform or mail me whenever the update is released. My contact is askannancivil@gmail.com

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

Sye — Wed, 11 May 2016 19:03:26 GMT

We investigated the issue and found that deflection check as per AISC 360, IS 800, S16-14 codes are always reporting last load case in the serviceability envelope as critical load case for deflection check. The design however is correct and reports the correct critical ratio. It is just the reporting of the critical load case which is incorrect and that too when deflection governs. So for any design where deflection is not the governing criteria, this reporting error does not have any effect. This error is found to exist in version 20.07.11.70 and will affect versions 20.07.11.50 and 20.07.11.33 too. It will be addressed in STAAD.Pro SS6 SP3 version scheduled for release in Q2 of 2016. The issue is now reported with id# 438681 at

communities.bentley.com/.../22866.known-issues-in-staad-pro-ss6

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

Sye — Mon, 09 May 2016 23:27:14 GMT

Ok thanks. I am looking into it and will get back to you with my findings.

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

kannan as — Sun, 08 May 2016 11:58:57 GMT

communities.bentley.com/.../SKID14A_5F00_Inplace-Anlaysis_5F00_03052016.stdI used the latest version 20.07.11.70. But i am getting the same result for deflection the last load case in the envelope is only listed in the unity check. Please find the attached staad file.

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

Sye — Wed, 04 May 2016 18:55:07 GMT

The following wiki should be a one stop shop for all verification documents related to the AISC 360 implementation in STAAD.Pro

communities.bentley.com/.../28192.staad-pro-verification-documents-related-to-aisc-360-specifications

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

kannan as — Wed, 04 May 2016 06:03:40 GMT

Hi, Can you provide the link to download the validation maual for AISC code 360/10.

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

Sye — Wed, 04 May 2016 00:20:42 GMT

I think you are using an older version of STAAD.Pro. I vaguely remember that there was a discrepancy with reporting the critical load case for deflection in some earlier version. Try with the latest 20.07.11.70 version and you should not have this issue. I checked with 20.07.11.70 and the critical load case reporting seems consistent.

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

kannan as — Tue, 03 May 2016 09:33:51 GMT

communities.bentley.com/.../2402.2330.Structure1_5F00_rev.stdHi, If you check the output of the file in unity check Tab. You will notice for the deflection of member no #3 maximum deflection is for case 101 but in the unity check dialogue its showing 107. I noticed that for the deflection check envelope the last case load no only it is considering in the analysis or only for the output it is giving like that. If anyone had noticed this before please let me know the solution.

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

Sye — Thu, 07 Apr 2016 17:26:59 GMT

We do understand where you are coming from and the fact that with the way it is currently implemented, it could result in a significant amount of extra work in scenarios where the same load combinations need to be checked both for serviceability and strength. An enhancement request ( Id # 334336) has been filed asking for this to be modified.

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

DSANJU — Thu, 07 Apr 2016 13:52:23 GMT

You can try the following:

DEFINE ENVELOPE

1 3 TO 6 ENVELOPE 1 TYPE STRESS
1 3 TO 6 ENVELOPE 2 TYPE SERVICEABILITY
END DEFINE ENVELOPE
*
LOAD LIST ENV 1 2
*
PARAMETER 1
CODE AISC UNIFIED 2010
DFF 500 MEMB 3 TO 5 8
FYLD 248213 MEMB 3 TO 5 8
FU 413688 MEMB 3 TO 5 8
TRACK 2 ALL
CHECK CODE MEMB 3 TO 5 8

communities.bentley.com/.../a1t.zip

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

Sudip Narayan Choudhury — Thu, 07 Apr 2016 12:10:29 GMT

I can answer the part on why the limitation has been set - In general the codes have distinct load combinations for Serviceability and Strength Limit States - this is true for all the codes I can think of - Indian, Eurocode or BS. Refer to clause 2.5 of BS 5950-1:2000 for an example.

For the part of the said inappropriate message, we will advise the developers to put in a more reasonable one.

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

vivekshine — Thu, 07 Apr 2016 11:10:44 GMT

OK thanks.
Dont know why such a limitations.

Either STAAD has to remove the limitation or should trigger proper warning (**WARNING- Deflection check of member # 4 will not be performed as service and service envelope has same load combinations)

Current warning "service envelope not provided" will confuse the users.

Currently I copied the load combination and just changed the load combination numbers used in stress envelope.

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
*
LOAD COMB 11 GENERATED AISC GENERAL 1
1 1.0
LOAD COMB 12 GENERATED AISC GENERAL 2
1 1.0 2 1.0
LOAD COMB 13 GENERATED AISC GENERAL 3
1 1.0 2 0.75
LOAD COMB 14 GENERATED AISC GENERAL 4
1 0.6
PERFORM ANALYSIS
*
DEFINE ENVELOPE
1 3 TO 6 ENVELOPE 1 TYPE SERVICEABILITY
1 11 to 14 ENVELOPE 2 TYPE STRESS
END DEFINE ENVELOPE
*
LOAD LIST ENV 1 2
*
PARAMETER 1
CODE AISC UNIFIED 2010
DFF 500 MEMB 3 TO 5 8
FYLD 248213 MEMB 3 TO 5 8
FU 413688 MEMB 3 TO 5 8
TRACK 2 ALL
CHECK CODE MEMB 3 TO 5 8

FINISH

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

Rajat — Thu, 07 Apr 2016 10:42:24 GMT

The load cases that are assigned to the serviceability load envelope happen to be the same as the ones that are assigned to the strength envelope. Thus, both envelopes have the same set of load cases. The AISC 360 design module in STAAD is current not set up to handle this situation currently. In other words, the load cases in those two envelopes need to be distinct and have no commonality. This limitation is expected to be removed in a future version.

So, here is what you can do presently. For each of the cases 1 and 3 to 6, create load combinations that are simply 1.0 times the respectives cases (Load combination 11 = 1 * LC1, Load combination 13 = 1 + LC3 and so on). Then, assign those combination cases to one of those envelopes.

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

vivekshine — Thu, 07 Apr 2016 10:00:25 GMT

Thanks.

In service and stress load combination will be same so I used same load combinations in different envelopes.
In engineering calculation there is no restrictions to use one combination for different type of designs. The why STAAD is restricted?

Even if that is restricted how it shows "service envelope not provided". 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.

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

DSANJU — Thu, 07 Apr 2016 09:37:35 GMT

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

communities.bentley.com/.../2465.a1.std

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

vivekshine — Thu, 07 Apr 2016 05:09:32 GMT

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

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

Sye — Tue, 09 Feb 2016 01:21:53 GMT

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.

communities.bentley.com/.../2330.Structure1_5F00_rev.std

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

siwalak khamnurak — Mon, 08 Feb 2016 23:42:00 GMT

Please see my first code.
If I prefer to use ASD not LRFD why I must use "STRENGTH ENVELOPE"?
Do you understand me?
Regard

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

DSANJU — Mon, 08 Feb 2016 13:13:35 GMT

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

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

siwalak khamnurak — Mon, 08 Feb 2016 12:17:56 GMT

OK. This is an improvement and I need one more thing about this.
As I mention above LOAD LIST ENVELOPE ... can only used for check deflection but cannot used for stress ratio check.
Please make this command can used for both to avoid confusing.
Regard.

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

DSANJU — Mon, 08 Feb 2016 08:34:56 GMT

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.