Prokon 1

[Melad Saad]

Hi Experts,, Hope this inquiry finds you all well
In Prokon last version 3.1, the connections of the structure (fixed, pine and roller) are appeared as (XYZ, XY, Y, XYZxyz, XYz, Yxz).
Can anyone explain to me which of them Pine and which roller. Also which should I used in the frame between beam and column if it is fixed connections.
Many thanks

 

[BAretired]

I have never used Prokon, so I'm not an expert, but would say that XY is the pin and Y is a horizontal roller. If the roller is vertical, it would presumably be labelled X. If the roller is on a slope, Y/X or X/Y would need to be specified.

BA

 

[BAretired]

Also which should I used in the frame between beam and column if it is fixed connections.

Ordinarily, frames do not have fixed connections between beams and columns. Usually the joints at each end of each member in a frame are free to rotate or translate, so that the X, Y and Z components are solved by the computer. It is only for supports that the designations are required to indicate what type of support it is.

BA

 

[BAretired]

I had a brief look at the tutorial. Either my hearing is getting a lot worse or there is no sound in the video. I'm not exactly sure what the XYZxyz designations represent but I expect upper case indicates a fixed component, i.e. an external reaction while lower case indicates releases within the frame...not sure.

Perhaps others can comment on this.


BA

 

[jayrod12]

In Risa, capital letters are global directions. Lowercase are local directions relative to each member.

For example if you had the global Y axis as your vertical axis, gravity would act in the negative Y direction. However for a beam, the local y direction would be an axial load applied to the beam.

Hopefully that makes sense.

Perhaps this program is similar.

 

[r13]

Interesting program.

Note that all supports are translation support only (XYZ).
If the grey beam is not meant to transfer the generated moment, the end conditions need to be released. If the end condition is changed to a torsional fixed end condition (xy release), the analysis is successful and the output corresponds to what is expected (shown in Figure 2).

Figure 2: Moment diagram, torsional fixed end condition.

 

[BAretired]

For example if you had the global Y axis as your vertical axis, gravity would act in the negative Y direction. However for a beam, the local y direction would be an axial load applied to the beam.

Hopefully that makes sense.

The designations XYZxyz seem to be referring to nodes, not members. Nodes do not have direction, so I would expect the upper case letters to apply. Don't know how to interpret the lower case designation and the tutorial is not clear about that.

BA

 

[Settingsun]

I also don't know Prokon specifically but node restraints are usually the 6 possible movements: three translational and three rotational. That's my guess and should be simple to confirm by a trial analysis.

 

[r13]

The diagram indicates XYZ are translation supports (restrains), xyz could be rotation supports (restrains).

 

[BAretired]

steveh49 & retired13,

I think you have both hit the nail on the head. I now realize that the tutorial I was viewing was for a 2D frame. For a 3D frame, it all makes sense now.

BA