Josh,
I did just now have another project that I am using member area distribution and the transient loads were wonky so I tried your method for changing the mesh and it does appear to make a significant difference. Still has some weird things like loads to e^-17 but much more accurate. Thanks...
Thank you both for your input, but that's not exactly what I am seeing in the handful of projects I've started using this feature for. Most projects I have used this feature on have had spaces larger than 10', smaller than 10', or a mix of both spaces. Even spaces as little as 2' O.C. have...
It hit me this morning that the load is applied in the appropriate direction but because my "quadrants" are more trapezoidal shaped rather than square/rectangle that the girders are in the load path. I was able to test this on a simple model. And if I think about it that would be the appropriate...
Good Afternoon All,
This is the second model I have run into this issue on. I am using member area loads (Parallel to A-B) to distribute a load one way to my floor beams which should then carry the loads to their girders, seems pretty straight forward.
But when I look at the transient loads...
I agree. And unfortunately I'm probably the heaviest user of RISA in my office and never really got any formal training on it so I'm kinda learning as I go.
By 3D effects I mean other members deforming causing additional deformation of the member in question. Some of which is accounted for in the supporting members and is easy to take out. Other engineers in my office use the same term and I assumed that's also what they meant but not entirely sure.
Thank you all. Turning the adjust stiffness off on the individual beam gave me my hand calc answer, and turning it off globally gave me the correct answer minus some 3D effects. So basically you would want to leave that on for strength calcs and then turn it off when checking service deflections?
Does RISA take something into consideration when calculating deflections that simple hand calcs do not? I've had other projects where hand checks have yielded similar results but I always chalked up the difference to 3D effects. But for my current project an issue caused me to run a beam simply...
So I have determined why the results between Elements and Risa are so different. Risa uses thick plates as the link JoshPlum shared above states, and Elements uses thin plate assumptions. The difference in my moment magnitudes between the programs is similar to those shown in one of the figures...
Somehow all my plates got renumbered after I compiled my spreadsheet, but from what I recall from yesterday it was the plates closest to the supports and center. The plate forces for the plates in between those areas varied with some of them having the highest magnitude. The ones with the high...
Thank you both for the responses.
JAE: Risa and spMats have 1.0 factor with the one point load and self weight turned on. I'm not too familiar with Ram Elements, but best I can tell that is all that is being considered as well. All models have a 1.0 factor from what I can tell (couldn't figure...
I am trying to model a section of a retaining wall that is very close to an elevator pit and some steel columns in Risa 3D. I believe that my model is correct but the engineer I am doing this for is not sure about the Mxy result and more specifically adding it to Mxx and Myy for reinforcement...
