Movable bridge bearing modelling

[Anonymous]

Hello.I am trying to model a double leaf balance beam bridge. The solution I 'd like to apply is as shown in the attached picture. This bearing is installed at the top of a tower. The problem I have come across is a way to model it in Robot to get expected results.

 

I need it to be a sort of force transition to get internal force in the tower which means that the resulting diagram of bending moment should look like in the pictures above). As could be seen,on the bar imitating the bearing, there is no bending moment displayed yet they transfer the load.

Any help would be appreciated.

[Rafacascudo · Accepted solution]

I built the model following the figures you sent.I didn´t know the exact bar properties ,but the results I got are pretty similar of those in your picture

Load 1

Load 2

Load 1+2

Your "dotted" bar should be  " compression only" type ( geometry/additional attributes/advanced bar properties) , Cable should be tension only. And the other pinned bearing should have a moment release on top of it.

Model attached.

[Anonymous]

Thank you for your replay. Finally, as it's a preliminary concept project, I have solved my problem by hand using basic statics. Nevertheless I will try to model it in Robot to verify the results and learn a new thing. 

I would appreciate a file with the above solution saved in an older versions of Robot. I am using the 2015 version and when I try to open it, some error is displaying. 

Thank you in advance.

Kind regards

[Rafacascudo]

it´s not possible to save in a previous RSA version like in autocad.

Try to open it in RSA 2015.It´s just a warning. I opened here and results are the same as in RSA2016

[Anonymous]

I thought so. Now it is running fine. I got an error several times before. 

Thanks for help once more

[Anonymous]

One last thing. Why the order of magnitude is lower than for the analytical solution? The results look like they are divided by 10 for some reason. Is there anyexplanation for that?

[Rafacascudo]

maybe they are using my "job preferences" where the forces are in tf

[Anonymous]

Yes indeed. The problem was in units. I have changed it and now it works fine

thanks again