marque13, I have noticed that and it is quite annoying when displaying moments on beams since it will give large moments to walls (displayed as beams now) and you have to zoom in to be able to see moments on actual beams.
I would love to know how to get rid of that.
drawoh,
so you're predicting a numerical error? This is kinda like a practical analysis tho, where loads and spans are pretty reasonable, deflections are small but a 15% difference in stress is surely not accurate enough, don't you think?
JStephen, at midway along the beam the stresses are almost identical. Does that mean it can't be shear stresses at the support causing the difference? I have modeled the fix end by fixing all nodes at the support in all directions. By parallel to the beam you mean normal stresses? Yes I know...
bookowski, yeah M/S by hand calcs. Without refining the mesh and just releasing the vertical restraints except the bottom, I get very close stresses to the theoretical values. Thanks :)
IDS, Yes it is a 2D analysis with plane stress elements.
If I restrain only the base node vertically, the...
Hi all,
To test out a FEA software, I modeled a cantilever beam 6m long and 0.7m deep with a concentrated load at the tip of the beam. I compared the stresses at the support from FEA to those obtained by simple bending theory (Euler-Bernoulli), I got a difference of about 15% (FEA is larger)...
Hmmm, I fiddled around with it today at work. I am not sure we add immediate+long term sustained cracked. Maybe long term cracked in SAFE is the total long term deflection accounting for creep and shrinkage.
Hopefully someone has some insights on this.
Hey guys,
I am just wondering what load combinations am I supposed to be using when conducting a non-linear cracked analysis for determination of immediate and long term deflections on SAFE 14?
I added 6 load cases, Dead-Immediate (Cracked), SDL-Immediate (Cracked), Live-Immediate (Cracked)...
Hello everyone,
I have seen in the SAFE 14 manual that they use an equation for the depth of the compression block in concrete according to AS 8.1.2.2, I could not find the equation in the code, and I tried to get at it without much luck. The equation is a = d - sqrt(d^2-(2M*/0.85f'c*phi*b))
I...
Hi all,
I have a three-span continuous bridge. I am undertaking a project which involves comparing the live load distribution factors obtained by AASHTO LRFD formulas to the distribution factors obtained by finite element analysis. I have obtained the distribution factors from LRFD, and I have...
Thanks for all the responses guys. Its good to know that I am not alone!
I find myself wanting to read books from cover to cover in case I miss something however I never get to finish them as I get sick of them, some earlier than others. Will start looking through and browsing for chapters...
Hi all,
Just a quick question, when you guys read a book to enhance your knowledge, do you read the whole book from start to finish or pick and choose what you wanna read? Or any techniques you guys use to get the most out of your reading?
Cheers
Hey, thanks for your reply.
Yeah the bending moment results are half of what I am expecting. What is the correct position of the centroid of the slab w.r.t centroid of the girder? Shouldn't they coincide?
Thank you!
Hello,
I have used Strand7 to model a simple span I-girder bridge using plate elements for deck and beam elements for the girders with centroids of both coinciding. I am getting good results for analysis of bridge under dead load however when I add a truck load, I get very different results...
