Parishith J's Communities Activities

What members to release in a truss space frame?

Karl R. — Mon, 29 Apr 2019 08:52:09 GMT

I'm performing analysis of 3D space truss of an existing structure. My current specs are truss spec for diagonal and vertical member. While I let both top and bottom chords as continuous member. I used ACI 360-10 for code check. There is also a carrier truss which are perpendicular to the truss with failed top chords. I defined the unsupported length of bottom chord as the spacing of horizontal strutts. My question is, what members should be released? Is my current released members correct?

Warning when applying Response Spectrum Analysis

Parishith J — Fri, 25 Dec 2020 05:50:58 GMT

Hello Experts,

While analyzing the model by response spectrum analysis, I do receive the following warning while specifying seismic direction as "Y".

***WARNING : EARTHQUAKE MODE IS NOT AVAILABLE FOR X AND Z DIRECTIONS ****

Whether this can be neglected?

Regards,

Parishith Jayan

Optimization using OpenSTAAD

Parishith J — Tue, 03 Nov 2020 11:34:14 GMT

I am recently using openSTAAD for automating my steel design works. I am aware that applying loads and load combinations are possible using openSTAAD.

OpenSTAAD documentation does not elaborately shows how to apply design parameters for steel design or I could not interpret how to apply design parameters using openSTAAD. I am trying to optimize my steel design automatically using openSTAAD functions. Kindly clarify, whether it is possible to do that?

Also, show some insight regarding applying design parameters in openSTAAD, so that i could design some simple steel beams using openSTAAD functions.

Kindly revert back ASAP...

Regards,

Parishith Jayan.

Response Spectrum Analysis as per Eurocode

Parishith J — Thu, 24 Dec 2020 12:02:40 GMT

Hello Experts,

I am not well versed with the dynamic analysis, since we could not perform linear static analysis for seismic load application as per Eurocode, Someone please guide me how to apply the response spectrum properly as per Eurocode.

I tried with the example EC8 frame from STAAD installation folder and did like that. Getting some of the following warnings.

*****************************************************************************************************************************************

***WARNING: NO RIGID FLOOR DIAPHRAGM EXISTS FOR THE STRUCTURE.
RESULTS ON EARTHQUAKE MODE IN USER-INTERFACE MAY BE APPROXIMATE.

*** Note: ALL MASS RELATED WARNINGS, IF ANY, WILL BE WRITTEN IN _MASSEURO.TXT FILE.

** WARNING : NO MASS IS DEFINED AT LEVEL 12.00 MET . OUTPUT RESULT MAY BE ERRONEOUS.

** WARNING : NO MASS IS DEFINED AT LEVEL 23.70 MET . OUTPUT RESULT MAY BE ERRONEOUS.

** WARNING : NO MASS IS DEFINED AT LEVEL 33.43 MET . OUTPUT RESULT MAY BE ERRONEOUS.

** WARNING : NO MASS IS DEFINED AT LEVEL 34.56 MET . OUTPUT RESULT MAY BE ERRONEOUS.

*****************************************************************************************************************************************

I was in a confusion that, whether I can neglect these warnings or how to get rid of them. It will be helpful if some Experts throw some light into this topic.

And for your reference, this is my input.

*****************************************************************************************************************************************

CUT OFF MODE SHAPE 50
LOAD 1 LOADTYPE Seismic TITLE SEISMIC X
JOINT LOAD
1 FX 5.38
5 FX 6.54
18 FX 59.65
22 FX 55.84
35 FX 59.6
39 FX 54.2
52 FX 5.58
56 FX 8.27
69 FX 12.44
73 FX 12.44
86 FX 12.42
90 FX 12.42
103 FX 14.02
107 FX 14.03
120 FX 12.44
124 FX 12.44
137 FX 12.33
141 FX 12.33
163 FX 23.53
164 FX 24.16
165 FX 24.16
166 FX 23.53
2 FX 220.98
4 FX 215.71
19 FX 313.11
21 FX 304.23
36 FX 301.61
38 FX 294.23
53 FX 210.41
55 FX 206.72
70 FX 208.66
72 FX 208.65
87 FX 274.69
89 FX 274.68
104 FX 264.62
106 FX 265.24
121 FX 208.58
123 FX 209.22
138 FX 207.51
140 FX 207.51
**
1 FY 5.38
5 FY 6.54
18 FY 59.65
22 FY 55.84
35 FY 59.6
39 FY 54.2
52 FY 5.58
56 FY 8.27
69 FY 12.44
73 FY 12.44
86 FY 12.42
90 FY 12.42
103 FY 14.02
107 FY 14.03
120 FY 12.44
124 FY 12.44
137 FY 12.33
141 FY 12.33
163 FY 23.53
164 FY 24.16
165 FY 24.16
166 FY 23.53
2 FY 220.98
4 FY 215.71
19 FY 313.11
21 FY 304.23
36 FY 301.61
38 FY 294.23
53 FY 210.41
55 FY 206.72
70 FY 208.66
72 FY 208.65
87 FY 274.69
89 FY 274.68
104 FY 264.62
106 FY 265.24
121 FY 208.58
123 FY 209.22
138 FY 207.51
140 FY 207.51
**
1 FZ 5.38
5 FZ 6.54
18 FZ 59.65
22 FZ 55.84
35 FZ 59.6
39 FZ 54.2
52 FZ 5.58
56 FZ 8.27
69 FZ 12.44
73 FZ 12.44
86 FZ 12.42
90 FZ 12.42
103 FZ 14.02
107 FZ 14.03
120 FZ 12.44
124 FZ 12.44
137 FZ 12.33
141 FZ 12.33
163 FZ 23.53
164 FZ 24.16
165 FZ 24.16
166 FZ 23.53
2 FZ 220.98
4 FZ 215.71
19 FZ 313.11
21 FZ 304.23
36 FZ 301.61
38 FZ 294.23
53 FZ 210.41
55 FZ 206.72
70 FZ 208.66
72 FZ 208.65
87 FZ 274.69
89 FZ 274.68
104 FZ 264.62
106 FZ 265.24
121 FZ 208.58
123 FZ 209.22
138 FZ 207.51
140 FZ 207.51
SPECTRUM CQC EURO 2004 ELASTIC RS1 X 1 ACC DAMP 0.05 LIN DOMINANT 1
SOIL TYPE D ALPHA 0.12 Q 1.5
********************
LOAD 2 LOADTYPE Seismic TITLE SEISMIC Y
SPECTRUM CQC EURO 2004 ELASTIC RS1 Y 1 ACC DAMP 0.05 LIN
SOIL TYPE D ALPHA 0.12 Q 1.5
********************
LOAD 3 LOADTYPE Seismic TITLE SEISMIC Z
SPECTRUM CQC EURO 2004 ELASTIC RS1 Z 1 ACC DAMP 0.05 LIN
SOIL TYPE D ALPHA 0.12 Q 1.5
*****
PERFORM ANALYSIS
CHANGE

********************************************************************************************************************************

Thanks in advance.

Composite Beam Design as per IS Standards

Parishith J — Mon, 06 Jul 2020 06:17:11 GMT

Is it possible to design a composite beam as per IS standard? If it is so, kindly attach a technical reference to work with.

Modelling Portal Bracing in a steel multi storey building?

Parishith J — Fri, 13 Mar 2020 11:57:59 GMT

I am designing a STG building in STAAD Pro connect edition. In actual case, i do have portal bracing for full height of the building (say 18m). How to model this portal in the STAAD model. Kindly revert back as soon as possible.

If someone have an example model, kindly attach the model for the reference.

Query regarding mismatch of results for design of Steel Beam-Column as per IS:800-2007

Parishith J — Fri, 28 Dec 2018 11:02:11 GMT

Sir,

I hereby attached a staad frame and a pdf file. I have tried to design one beam column from the staad file manually. While doing so, there is a mismatch between the staad result and my manual result. Why is that happening. I have done the same design strength checks from specified clauses.

I checked the design calculation for member no. "8" from the attached staad file. The result comparison and manual design calculation for that particular member is in the pdf file. Please go through the attached staad and pdf file and clarify me why there is such deviations between manual and staad results.

Thanks in advance,

Parishith Jayan.

communities.bentley.com/.../Frame_2D00_1.std communities.bentley.com/.../Beam-Column_2D00_-IS-800.pdf

How to provide a support condition for mezzanine beam which is supported by a anchor rod?

Parishith J — Thu, 07 Jun 2018 07:52:11 GMT

I am designing a roof structure which is about to be supported by a mezzanine platform. The whole platform is supported on a anchor rod at different locations It will be like, there are anchor rods at several locations on the mezzanine beam, which is hanging on the support of the anchor rod. How do I assign this support in STAAD ?

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