Instability at a Joint in the MZ direction

Obiajulu Onyemeh — Thu, 17 Jun 2021 09:17:34 GMT

Hello,

I was carrying out an analysis for a frame and was informed of instability at a joint. Although i have two pinned joints in 3D model space , i have included releases to take care of out of plane moments and torsion on the top beam. However, the structure seems to be unresponsive and still shows up warnings of instability. Kindly help.

STAAD SPACE GOAL POST ANALYSIS
START JOB INFORMATION
ENGINEER DATE 16-Jun-21
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 0 1.1 0; 3 0 0 2.8; 4 0 1.1 2.8;
MEMBER INCIDENCES
1 3 4; 2 4 2; 3 2 1;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 2.05e+08
POISSON 0.3
DENSITY 76.8195
ALPHA 1.2e-05
DAMP 0.03
TYPE STEEL
STRENGTH RY 1.5 RT 1.2
ISOTROPIC STEEL_275_NMM2
E 2.05e+08
POISSON 0.3
DENSITY 77
ALPHA 1.2e-05
DAMP 0.03
TYPE STEEL
STRENGTH FY 275000 FU 410000 RY 1.5 RT 1.2
END DEFINE MATERIAL
CONSTANTS
MATERIAL STEEL_275_NMM2 ALL
MEMBER PROPERTY BRITISH
1 TO 3 TABLE ST UC203X203X46
SUPPORTS
1 3 PINNED
MEMBER RELEASE
2 START MZ
2 END MZ
LOAD 1 LOADTYPE Dead TITLE DL1- PIPING AND FRAME S/W
SELFWEIGHT Y -1.1
MEMBER LOAD
2 CON GY -2.33 0.158 0
2 CON GY -0.27 0.533 0
2 CON GY -4.47 1.048 0
2 CON GY -0.66 1.625 0
2 CON GY -0.71 1.802 0
2 CON GY -0.65 1.981 0
2 CON GY -0.66 2.27 0
2 CON GY -0.23 2.464 0
2 CON GY -0.23 2.586 0
2 CON GY -0.25 2.924 0
LOAD 2 LOADTYPE Dead TITLE DL2 - CABLE TRAY LOAD
MEMBER LOAD
2 CON GY -3.5 1.5 0
LOAD 3 LOADTYPE Live TITLE LL1 - WATER LOAD
MEMBER LOAD
2 CON GY -1.4 0.158 0
2 CON GY -0.04 0.533 0
2 CON GY -3.68 1.048 0
2 CON GY -0.15 1.625 0
2 CON GY -0.15 1.981 0
2 CON GY -0.15 2.27 0
2 CON GY -0.16 1.802 0
2 CON GY -0.03 2.464 0
2 CON GY -0.03 2.586 0
2 CON GY -0.03 2.924 0
LOAD 4 LOADTYPE Live TITLE LL2 - THERMAL
MEMBER LOAD
2 CON GX -0.34 0.158 0
2 CON GX -0.03 0.533 0
2 CON GX -0.73 1.048 0
2 CON GX -0.07 1.625 0
2 CON GX -0.08 1.802 0
2 CON GX -0.07 1.981 0
2 CON GX -0.07 2.27 0
2 CON GX -0.02 2.464 0
2 CON GX -0.02 2.586 0
2 CON GX -0.03 2.924 0
LOAD 5 LOADTYPE Live TITLE LL3 - FRICTION
MEMBER LOAD
2 CON GX -0.9 0.158
2 CON GX -0.07 0.533
2 CON GX -1.96 1.048 0
LOAD COMB 6 SLS 1
1 1.0 2 1.0 3 1.0 4 0.6 5 0.6
LOAD COMB 7 SLS 2
1 1.0 2 1.0 3 0.6 4 0.6 5 1.0
LOAD COMB 8 ULS 1
1 1.35 2 1.35 3 1.5 4 0.9 5 0.9
LOAD COMB 9 ULS 2
1 1.35 2 1.35 3 0.9 4 0.9 5 1.5
LOAD COMB 10 ULS GEO
1 1.0 2 1.0 3 1.3 4 0.78 5 0.78
LOAD COMB 11 ULS GEO 2
1 1.0 2 1.0 3 0.78 4 0.78 5 1.3
PERFORM ANALYSIS
DEFINE ENVELOPE
6 7 ENVELOPE 1 TYPE SERVICEABILITY
8 9 ENVELOPE 2 TYPE STRENGTH
8 9 ENVELOPE 3 TYPE CONNECTION
10 11 ENVELOPE 4
END DEFINE ENVELOPE
PARAMETER 1
CODE EN 1993-1-1:2005
CHECK CODE ALL
PARAMETER 2
CODE EN 1993-1-1:2005
STEEL TAKE OFF ALL
FINISH

Beam -Column Haunch connection - translating design from Staad.Pro to RAM connection

Obiajulu Onyemeh — Sat, 31 Oct 2020 22:28:34 GMT

Hello,

Working on a steel framed structure on Staad pro. and I am currently trying to carry out a beam-column connection for the rafter- column connection using a haunch. When i try to create the connection in the RAM module within staad pro, using the Bolted End Plate BCF (haunched) for Eurocode option, i get a reply saying the connection cannot be assigned due to an error of the BCF being less than the maximum allowable value. Vertical angle (deg).

Please see attached snap shot.

question then is , what caused this error?, are there limits to the slope or skew that Ram connection can take?. How can i get the Rafter- column connection fixed without rework?.

Is possible to design this type of apex haunch on staad pro or ram connect edition

hakeem olokunola — Tue, 30 Jul 2019 03:19:09 GMT

I was working on a portal frame and I need to design this type of apex haunch on staad pro or ram connection

pictures attached below

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Sat, 31 Oct 2020 11:40:42 GMT

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Instability at a Joint in the MZ direction

Beam -Column Haunch connection - translating design from Staad.Pro to RAM connection

Is possible to design this type of apex haunch on staad pro or ram connect edition

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