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  1. saburo

    Etabs Seismic Mass

    I think if you have a look at the " Assembled mass", scroll down to the bottom, there will be a summary of assembled mass for each level and the total mass. The seismic mass should be total mass minus mass at the BASE, as bottom half of lowest level does not count. I think you should get pretty...
  2. saburo

    ETABS SECTION DESIGNER

    Hi I have a query regarding the wall design. I use SD for the wall design(not to design but just check the capacity with given reinforcement). The wall is a C- shape + one of the flanges has a return wall. I have set up spectrum cases in ETABS to design. Now I have the axial load for EQ and M2...
  3. saburo

    Core wall out of plane design

    Hi I am designing a box shaped core wall surrounded by two rows of perimeter columns for a 40 storey building. The wall is predominantly taking in-plane shear/moment from the lateral force. The flexural and shear demand is not significant and easily dealt with. My question will be about the out...
  4. saburo

    Dynamic Concrete Modulus of Elasticity

    I am after some info on Dynamic Ecd value to use in ETABS. I may have seen Ecd = 1.35 Ec somewhere in New Zealand concrete code, but unsure where it was from because I have not got the code in front of me now. I have heard Ec(4700sqrt(fc') or whatever) in ACI is thought to be based on secant...
  5. saburo

    How do you guys check mass/weight in ETABS model

    Just wondered how you guys check mass/weight in ETABS model. And more to the point, how you do define the mass sources, "specified mass + self"??. the reason i ask is that the model i am dealing with at present has area mass representing sdl+some LL assigned to the floor. I thought it would be...
  6. saburo

    ETABS Floor seismic and wind acceleration

    Stressed Thank you very much for your input and sorry about my lack of study!! It seems you guys are well ahead of us. I was aware that ETABS can not generate dynamic wind loads for sure but did not know ETABS can handle TH wind dynamic analysis to be honest. I only have some experience with...
  7. saburo

    How to model cracked section in Etabs

    For beam/line elements, it is quite simple, I33 or whatever can be set to be 0.35. Fine. But for walls that modeled with shell elements, the problem is more complex. If the wall is one straight wall, tweaking f11, f12,f22 would make sense in a way.(I would not touch m11, m22 modifier because...
  8. saburo

    ETABS Floor seismic and wind acceleration

    Stressed, What I meant by "ETABS can not perform dynamic wind analysis" is that ETABS can not perform time history wind response analysis with time dependent wind pressure (each time step)around the building(building each face has different wind pressure/suction distribution at any given time...
  9. saburo

    ETABS Floor seismic and wind acceleration

    I am not sure about what you are using the accelerations for. Are you designing parts/portion of the building or you checking acceleration for wind sensitivity? ETABS can not do the dynaminc wind response so take it the former. In any case, you should be careful because the accelerations in the...
  10. saburo

    "Semi Rigid Diaphragm"

    I have read the old thread(802-169700)regarding the usage of "Semi Rigid Diaphragm" that became available from ver 9?(Im not sure from what version to be honest). The thread basically states that the only usage of semi rigid diaphragms is to define the extent of the diaphragm(building width etc...
  11. saburo

    Adding eccentricity using "coefficient lateral force"

    Hi Bugsfinder Speaking of eccentricity ratio, i have made 1 storey square building to check what this means, the ratio turned out to be the percentage of the building width perpendicular to the quake direction. If your buildding is 10m wide, eccentricity 0.05 gives 0.5m x external force that has...
  12. saburo

    Adding eccentricity using "coefficient lateral force"

    Thanks for your reply Lixx. I have contacted the guy in CSI regarding this and got the same answer as you have got. I finally had to put some diaphragms and chosen one of the corner points within the diaphragm and assigned the global torsional force to the point.
  13. saburo

    Adding eccentricity using "coefficient lateral force"

    HI there I am currentlly using version 8.3.5 and wanted to achieve the accidental eccentricity (10% of the building width perpendicular to the eq direction) that NZS4203 requires. I made some loadcase ecc+ and ecc- for x and y direction trying to get that, but it seemed that ETABS is not putting...
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