warning instability at joint (STAAD) - Printable Version +- Civil Engineering Association (https://forum.civilea.com) +-- Forum: Software (https://forum.civilea.com/forum-65.html) +--- Forum: Software Installation Problems & Bugs (https://forum.civilea.com/forum-106.html) +---- Forum: Archive Problem (https://forum.civilea.com/forum-28.html) +---- Thread: warning instability at joint (STAAD) (/thread-3172.html) |
warning instability at joint (STAAD) - repsol - 08-31-2009 Hi guys ..i found this site very informative..I model a structure USING STAAD software but this warning keep on appearing in out put file..any help to solve this problem will greatly appreciated..thanks in advance.hope for your reply RE: ****warning instability at joint xxx(STAAD) - engr1900 - 09-01-2009 Hy can u post the staad file, error may be due to support condition chek it again whether fixed, hinge or roller bye RE: ****warning instability at joint xxx(STAAD) - jaks - 09-01-2009 Hi, The particular error may be due to the type of the model you are working with(Space/Plane). Suppose if you are working in a single plane and the model is Space, then this instability will be there. And suppose if you are working in a Space model and there are certain horizontal forces applied, you need to see that the loads are transferred to the bases. If your base supports are say pinned then you may need bracings/moment connections, likewise... I hope this might answer some of your problem if not all. Regards, # Upload your model/file if you are facing problem other than the above. RE: ****warning instability at joint xxx(STAAD) - repsol - 09-03-2009 engr1900,sent to your email the STAAD INPUT FILE of the said project...HOPE you can help me.A lot of thanks in advance hi jaks,thanks also for your reply.... RE: ****warning instability at joint xxx(STAAD) - engr1900 - 09-04-2009 Hy u can check there shud not be any multiple structures go to tools, check multiple structures, coz almost all softwares checks stiffness between elements try to change the column section coz beam has to transfer the load to columns, beam section must be equal or less second thing is as follows There are 2 important checks that should be carried out if instability messages are present. a) A static equilibrium check. This check will tell us whether all the applied loading flowed through the model into the supports. A satisfactory result would require that the applied loading be in equilibrium with the support reactions. b) The joint displacement check. This check will tell us whether the displacements in the model are within reasonable limits. If a load passes through a corresponding unstable degree of freedom, the structure will undergo excessive deflections at that degree of freedom. One may use the PRINT STATICS CHECK option in conjunction with the PERFORM ANALYSIS command to obtain a report of both the results mentioned in the above checks. The STAAD output file will contain a report similar to the following, for every primary load case that has been solved for : hope it will help u to sortout problem byee RE: ****warning instability at joint xxx(STAAD) - dynamics - 09-05-2009 Instability warning will usually occur when some of the members degree of freedom are released and forces in the structure are flowing in all axis i.e. by declaring the member as truss, compression or tension only but there other members connecting to that member in orthogonal direction thus transfer of loads from the orthogonal direction is not restrained by any other member because of the member specification of the other. There are several ways to address this issue depending on the type of structure declared in the analysis i.e space, plane or truss. Kindly attach your file so that I can check it and try to resolve your issue. RE: ****warning instability at joint xxx(STAAD) - engr1900 - 09-05-2009 instability in joints in staadpro
info: Hy u can havae more details reg your problem here Download Links: Code: *************************************** Generate By Civilea PostGen V1.3 RE: ****warning instability at joint xxx(STAAD) - repsol - 09-06-2009 hy guys, i just resolve the problem and now no instability messages occured.I also noticed that equilibrium exist base from the report of STATIC check.Big thanks for those email and advise.....more power to this site |