My apologies for the late response, notifications for this thread were hitting my spam folder.
@dhengr, you're right, I did not offer a great detail, please see attached for greater context.
@KootK... always with a killer detailed response, thank you. Because the deck is very long, the...
Good afternoon,
I am dealing with a pretty unique situation and it seems that the use of split rings is my only option.
In CSA O86, the "J" factors for split ring capacity deal with end/edge distances. If I am looking to install a 4" split ring in a vertically nail laminated 38x140 deck face...
Good afternoon,
I am in the process of reviewing some drawings for a bridge abutment repair/rehab. The front edge of the abutment back wall has a steel nosing angle, which attaches to the concrete via alternating (vertical/horizontal) nelson studs.
Does anyone know of a design criteria for...
@HotRod10
Thank you for the reply. The reason I am asking, is that, if you had, say, a vertical, diagonal, and top chord (at the end of the truss), for example, with the diagonal in tension, the top and vertical chords would be in compression. Would that not limit the propitiation of the...
@dhenger
I have attached an example gusset plate for the truss bridge I am working on.
I have already completed the fatigue checks for the incoming channels. My confusion lay in what stresses (Whitmore tension only? Block shear? Some other tension area?) should be checked, if any, for the...
Good afternoon,
I can't seem to find any literature on the fatigue analysis of bolted, slip critical gusset plates. My initial assumption was that I would be comparing the stress calculated at both the Whitmore Section and the Block Shear failure plane and compare it against the category B...
So quite some time ago @tennist had a post asking for help calculating the Warping Constant (Cw) of back to back channels:
https://www.eng-tips.com/viewthread.cfm?qid=367554
I have used the equation cited, but also compared it to the formula out of Roark's Formulas for Stress and Strain...
Wait a minute... I'm now looking at Galambos' assumed use of rx = 2*rx...
rx comp. for two side-by-side members be the same as rx for the single member.
A comp = 2*A
Ix comp = 2*Ix
rx=SQRT(2I/2A) = SQRT(I/A)...
I am beginning to believe that I have used this formula beyond it's function...
Thank you all so much for the information.
I have been comparing the values derived from the formula given in Roark's to the ones given in the excerpt I posted originally.
The formula in Roark's is given in the attachment for anyone reading this in the future, or whom may be interested now...
Using the values given for w-sections, does it stand to reason that back-to-back angles would be approximately 1.2A/Af and toe-to-toe angles A/Aw?
I see that my local university library has a copy of Pilkey that I am going to try and snag tonight.
@JoshPlum
Thank you for the reference, I am still seeing what I can dig up for Pilkey.
Do you have the section or page at hand?
I am seeing that
Buckling Strength of Metal Structures - Bleich
Steel Structures - McGuire
Both list n = 1.2 for rectangular sections and approximately 2 for w...
Good morning,
I am currently working through the analysis of a series of laced/battened columns. I am using:
Guide to Stability Design Criteria for Metal Structures - Galambos
Behavior of Laced and Battened Structural Members - Lin et. al. 1970
Both the book and the paper utilize a Shear Shape...
@OldBldgGuy
That was my first thought... After sleeping on it I've come to the conclusion that the code tossed this clause in in a sloppy, ill explained way. I believe that the code covers the "selective 1.0 m strip" approach by requiring detailed fabrication drawings. It also notes that the...
Good afternoon,
I'm plugging away on the design of a nail-laminated wood bridge deck today and have come across two clauses that state that shear need not be checked for vertically laminated wood decks.
From CSA S6:
"Cl.5.5.8 Transverse wood deck
Only the transverse moment need be analyzed...
Good morning,
I am working on the design of a nail-laminated bridge deck and don't understand the Butt Joint Stiffness Factor, kb.
kb = (Nb - 1)/Nb
Where "Nb = a measure of the frequency of butt joints in laminated wood decks, being for any 1.0 m wide band perpendicular to the laminates, the...
@dik, I get the same result using your numbers.
@OldBldgGuy, The deck is laminated in the transverse direction, so the swelling would be perpendicular to the grain. Using your chart for eastern white pine... unless the percentage should be represented by a decimal? If that's the case, 9 mm...
Good afternoon,
I am currently looking at a nail laminated bridge deck with 2x longitudinal running boards as a wearing surface.
I have already calculated the shrinkage/swelling of the deck due to changes in relative humidity. The total deck (~42m) will experience a dimensional change of...
@GregLocock
My apologies for not using more precise language. What I meant by 'primary natural frequency' was frequencies which have the highest mass participation. The point I was circling was, as the frequencies increase, less of the mass participates, and you may be exciting specific...
