Hello,
For the purpose of base plate design (LRFD), I don't get Mstrip and Beff values like I expext. I checked previous answers, but didn't get any clue. Please check attached pdf to see manuay calculated values and those from RAM.
Regards,
Here is a sample calculation from a prior question. The values don't match you case but it should explain how Ram Connection calculates Mstrip, Beff and Mpl. If it's not clear let me know.
In this sense we reproduce the calculations for the model:
Data.-
Pu = 39.4 kips (Uplift)
bf = 14.6 in
d = 14.2 in
N = 21 in
B = 21 in
Calculation.-
m = (N – 0.95*d) / 2 = 3.755 in
n = (B - 0.8*bf) / 2 = 4.66 in
For bending about the flange
Mpl = Mstrip / Beff
Mstrip = T*Arm
T = Pu/4 = 9.85 kips
Arm = m - Lev = 3.755 – 1.5 = 2.255 in
Mstrip = 1.85 kip-ft
Beff = Arm + Leh = 3.755 in (see the horizontal red line in the bellow figure)
Mpl = Mstrip / Beff = 5.91 kip-ft/ft
For bending about the web
Arm = n – Leh = 4.66 – 1.5 = 3.16 in
Mstrip = 2.59 kip-ft
Beff = Arm + Lev = 4.66 in (see the vertical red line in the bellow figure)
Mpl = Mstrip / Beff = 6.67 kip-ft/ft
So the most critical Mpl is for plate bending about the web line (the reported one) independently of the Analysis Axis Option.
Dear Seth,
Please can you explain what are the bending and yield line that RAM takes into account for the case when the anchors are "INSIDE" the column section (not outside). Please refer to DG1 2nd edition; example 4.5; figure 4.5.2. Also please find query.pdf in attachment.
This is very important to know, because RAM reports failure, and when I check it manual, I find it can pass (it differs a lot).
Thanks in advance.
I am seeing some different results in Ram Connection Stand-alone version 11.00.01.208 (see attached file). Please confirm that I have the forces, sections, materials and dimensions right. If so, and if the results still differ from Ram Connection in STAAD.pro, send me your STAAD file and confirm the version of that you are using.
Output:
File: BP_lrfd_UK_db_units.cnx
Base plate properties and tension force are in attachment.
I get some warnings if I use M30 bolts in those positions (too close to the weld line), but the Beff is still 81mm. It must be something about your version (or maybe the design code).
revised file: BP_lrfd_UK_db_units_M30.cnx