After further reading (page 4-7) I realize Table 4-12 is the application of the Sakla procedure for single angle compression members when section 5E cannot be met, as WillisV said. Thanks again WillisV.
Therefore if my previous calculation is correct there will be a 60% increase in capacity...
I'm still having trouble with this. I've been trying to calculate column loads for angles per the part 4 tables.
For example Table 4-12 for a L3x3x1/4 angle with KL=4' shows an allowable strength of 9.55 kips.
By my calcs: L/rx = 48/.842 = 57
per equation E5-1: (for a planar truss)
L/r = 72...
engstructural:
That sounds like what I've been doing up to now, calculating compression stress based on principle axis rz, then translating Mx into Mz and Mw moments, all for use in the combined stress equation. This produced a significant drop in capacity over concentric loaded angles...
I haven't used the AISC 13th Edition at all yet for design, I'm still using ASD 9.
Today I've tried to understand Section E5 concerning Single Angle Compression Members. Their logic for x-axis buckling makes a lot of sense, but it seems the new design procedure is based on equations E5-1...
Thanks for the comments. I'm going to modify my design calcs to use the eccentricity between the top chord angle cg and the surface where the two angles are welded together. Since in my opinion this will overestimate the bending moments in the top and bottom chords I'll have to come up with a...
For the diagonal bracing I solve as if they were concentrically loaded members. Since the CGs don't line up the members obviously aren't concentrically loaded so I use the technique in the AISC on page 3-55 for Single Angle Strut design and calculate the z and w axis bending stresses. As I...
Visual Basic isn't really obsolete but the newest version VB.net doesn't support the GOSUB statement which wrecks almost every VB program I've ever written. Last year I downloaded Visual Basic Express from Microsoft and it was free. It's actually pretty cool, but I still use VB6.
I use...
I'm reviewing the design of several truss conveyors constructed from angles. These have been modeled and solved using Multiframe. There are no gusset plates in these trusses, the angles are welded together by overlapping the legs and welding, creating an eccentrically loaded connection...
Try looking at the following... thread507-126960
They aren't really compatible methods but a while back I tried to work out an equivalent. Note that most comments in the thread did not support what I was trying to do. What I wanted was to develop a rule-of-thumb as a general guideline. It...
Here's a link to the Ryerson warehouse stocklist which indicates to me that there still could be a lot of A36 being shipped. Any opinions?
Regards,
-Mike
Back in the 80s I wrote a FORTRAN program to do a dynamic analysis of a mechanical system using modal analysis. I borrowed a lot from programs that the professors had available, but it was still a huge amount of work. Now I use Mathematica with all the matrix math and eigenvalues capabilities...
