Good morning,
I have problem with my steel truss bridge design, i've used member specification release MY;MZ and truss. Then this message came after i am running the analysis.
***WARNING - INSTABILITY AT JOINT 490 DIRECTION = MZ
PROBABLE CAUSE SINGULAR-ADDING WEAK SPRING
K-MATRIX DIAG= 3.4113601E+05 L-MATRIX DIAG= 5.8207661E-11 EQN NO 366
***NOTE - VERY WEAK SPRING ADDED FOR STABILITY
Then i change my member specification release to just MZ, but i am not sure this correct to describe my design with actual connection. Although the warning sign not shown anymore.
How do i have to solve this problem with "Very Weak Spring Added for Stability", do i have to change the direction of release specification member into MZ only or any suggestion regarding my design?. I attach my design file, the first is DESIGN-001-MYMZ.std with release MYMZ and the second is DESIGN-002-MZ. Hope you guys can help me to solve my problem. Thanks in advance!
Kind regards,
Muhammad IqbalDESIGN-001-MYMZ.stdDESIGN-002-MZ.std