How vehicle axle load is applied on the bridge deck in CSiBridge?

[netsonicyxf]

When defining vehicle load in CSiBridge / Sap2000, the axle load is input as point load.
I want to manully put the point load on the deck
But I can't assign point load to bridge deck (shell/plate) in CSiBridge / Sap2000.

So how this load is applied on the bridge deck in CSiBridge?

 

[MIKE_311]

Its been a while since I did it, it's not very intuitive, see if these help.

https://www.csiamerica.com/products/csibridge/videos

 

[netsonicyxf]

What I really want to do is manully putting the axle point load onto the deck.
but CSiBridge doesn't allow me to assign point load onto the area.

I want to know how CSiBridge "internally" assign the vehicle axle load onto the deck?

 

[STrctPono]

Are you running a grillage model or is the deck modeled with shell elements? For the latter approach... a shell element can only have forces applied at the nodes so my guess would be that the program distributes the load to the nearest surrounding nodes based on the location of the applied load relative to the plate. It will therefore be more accurate the more finely refined your mesh. I know that this is how MidasCivil does it so I would assume it is similar for CSiBridge.

 

[netsonicyxf]

Yes, I have to divide the shell at locations of point load.

BTW: Midas Civil allow you to define any load (point load, area load), and Midas can automatically distribute them to the shell
while user of CSiBridge need to divide area manually.

 

[STrctPono]

netsonicyxf,

That is unfortunate. One thing that I have done in the past when I have wanted to manually "walk" a moving load down the bridge is to model a flexible beam element along the line of the wheels. Even if the beam element doesn't coincide with a shell element node, you can then rigid link the beam nodes to the closest shell nodes. If done properly, it can save time and still produce relatively reliable results (so long as you are analyzing the superstructure and not the deck).

 

[netsonicyxf]

STrctPono,

Thanks you for the tip.