sponton
Structural
- Nov 11, 2014
- 139
Hiya,
I am designing a steel building with eccentrically braced frames [picture attached], the analysis was performed using RAM Structural System [my first time using it, i am a SAP/ETABs User]. The thing is that because of silly architectural requirements we are not allowed to use full frame bracing so we will have to turn the chevron braces into K-braces. Now the problem is that RAM doesn't really model these type of braces (I think) and it seems not to allow the creation of nodes for me to make the braces at the required locations with the desired configuration. I was wondering how off would i be if I use the shear frame forces provided for the original given configuration. The diaphragm is modeled as semirigid (I can't really manage to run it as flexible for some reason) so shear transmission is partially dependent on the stiffness of members.
My train of thought was to use the shear story forces from the first calculation, since the bracing configuration was the same [ heights and bay widths and bracing are composed of the same members (or I can make them)] so this would sort of permit a distribution more inclined towards geometric configuration rather than stiffness. Until that point everything seems to be making sense, but when I re-design the frame and modify the frame stiffness then the forces won't distribute in the manner they were designed for, is there anyone who has come across either designing braces like this or knows how to get it done in RAM?
thanks in advanced!
I am designing a steel building with eccentrically braced frames [picture attached], the analysis was performed using RAM Structural System [my first time using it, i am a SAP/ETABs User]. The thing is that because of silly architectural requirements we are not allowed to use full frame bracing so we will have to turn the chevron braces into K-braces. Now the problem is that RAM doesn't really model these type of braces (I think) and it seems not to allow the creation of nodes for me to make the braces at the required locations with the desired configuration. I was wondering how off would i be if I use the shear frame forces provided for the original given configuration. The diaphragm is modeled as semirigid (I can't really manage to run it as flexible for some reason) so shear transmission is partially dependent on the stiffness of members.
My train of thought was to use the shear story forces from the first calculation, since the bracing configuration was the same [ heights and bay widths and bracing are composed of the same members (or I can make them)] so this would sort of permit a distribution more inclined towards geometric configuration rather than stiffness. Until that point everything seems to be making sense, but when I re-design the frame and modify the frame stiffness then the forces won't distribute in the manner they were designed for, is there anyone who has come across either designing braces like this or knows how to get it done in RAM?
thanks in advanced!
