RISA Loading question

[AuEng99]

I am fairly young engineer, but I still insist on checking a lot of the program's results with hand calcs. This is always beneficial, because I checked the RISA results for a plate loading on a metal building. I noticed that the plate load was not being distributed correctly. From the old days of hand calculations, I new that 0.02 ksf distributed over beams 20 feet long @ 3 feet O.C. should give a Shear (V) result that is (0.02 ksf * 3 feet * 20 ft)/2 however the results are not even close to this.

When I apply a distributed load of 0.02 ksf over the beam, I get a Shear (V) equal to approximately (0.02 ksf * 3 feet * 20 ft)/2.

Can anyone help me find out what I need to do to get the plate loading to show up correctly?

 

[JoshPlumSE]

FYI: There is a RISA Technologies: RISA-3D forum. That might be a better place for a question like this that is more about program function than about structural engineering in general.

Without seeing your model, there is no way to know for sure why this would be. However, my suspicion is that you have not correctly meshed your plate elements. The first time anyone uses plate elements the tendency is to us one large plate and apply an surface load to the area of that plate. But, plate elements only have connectivity to their corner joints. So, they do not behave well unless they have been sub-meshed. Without that sub-meshing, the plate will probably carry the load directly into the support bypassing the beam completely.

 

[Eldorado]

I agree with Josh's assessment. Start by checking the reactions of your supports and verify the total of you reactions is as expected. If this is good, work your way back up to your plate connections and find out where the loads went.