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fmk wrote:
> yes.
>
> it's not one or the other, both are possible. it really depends on the
> structure and the load path. remember typically you just model the lateral
> system. if that frame is on the edge of a building, most loads might be
> coming to the column from the beams perpedindicular to the columns. If the
> frame was internal, the gravity loads could be coming from the beams in the
> system and the beams framing in from the perp. direction.


you mean that the load path of the gravity could change during the earthquake different from the static state, applying the gravity load on the beam-column node considers the change of load path in different frame? In the dynamic state, applying the gravity on nodes is more correct than on the beams? but I think the gravity load should be appled on the beams of the building whether in the static state or dynamic state, that feels more actual, isn't it?

fmk wrote:
> doesn't look like either is correct, though 1 would be closest!
>
> the gravity loads in the frame should only be those the frame will carry
> (otheriwse the axial forces in these members will be incorrect). leaning
> columns are provided for those bays to accout for mass and loads of those
> bays not accounted for.


Thank you for your reply!
you mean that the gravity load of force-resisting frame is only applied on the force resisting frame, and all the other gravity load of rest of the building is applied on the leaning column?
another question: some models simulate response of structures under earthquake, it usually applies the gravity load on the node, not the beams, does it mean doesn't consider the effect of beams applied gravity during the earthquake?

thanks a lot

hello，
I would like to use matlab call opensees to parameter analysis. However, I don't know how to update the model with parameters I interest, and how to automatic call opensees . Is there some examples or command about this?
thank you !

hello ， everyone
I used 2D model to represent a full frame, for example, there is ten bays in the full frame, and the 2D lateral force-resisting frame is only four of the ten bays. How to model the P-Delta effect? which one is the correct in the following two methods?
1、 the 2D lateral force-resisting frame presenting full building holds the weight of only half of the building, and some leaning columns represent half of the rest of the building. The gravity load is applied to the nodes with the mass in the lateral force-resisting frame and leaning columns.
2、 There isn't leaning column in the model, the 2D lateral force-resisting frame presenting full building holds the whole weight of the building , and gravity load is applied to the beams, using Geometric Transformation Command "geomTransf ColTransfType PDelta" to present P-Δ effects.
can you tell me which metod is correct to consider the P-Δ effects, or tell me any another way to model the building considering the P-Δ effects.

Look forword to your response, thank you.

hello, everyone:

I didn't use leaning columns to represent the PDelta effect in my model, I just used Geometric Transformation Command "geomTransf ColTransfType PDelta" , and the gravity load was applied to the elements(beams),
I don't know whether it is right to model the P-Δ effects. Is it the only way to model P-Δ effects with leaning columns?
Look forword to your response, thank you.

Dear moshref
can you send your TCL brace buckling code to my email?
11B933007@hit.edu.cn
Thanks