I contacted AWWA directly and they confirmed that there is a typo is equation 13-18. Ri should be Rc. I edited the original post to reflect the correct equation for searching purposes. Thanks everyone.
ASCE 7-10 15.7.6 is similar but equation the ASCE equation 15.7-6 doesn't even have an (R) in the denominator. I think this is why there is Section 15.7.7.1 for ASCE 7-10 which directs me to AWWA D-100 specifically for what I am doing. Thank you.
Hello everyone,
I am developing the seismic forces on a ground-supported, mechanically anchored water storage tank. I am currently at Section 13.2.9.2 where I calculate the impulse design acceleration (Ai) and the convective design acceleration (Ac). I noticed that equation 13-18 for (Ac) asks...
Hello All!
A customer wants me to check an existing equipment skid for operating load cases and a hoisting and rigging load case. This post is about the hoisting and rigging load case only and the application of ASME BTH-1.
The equipment skid is comprised of various pumps, compressors, pipes...
At MikeHalloran:
Thank you for the reply. The fabricator has already been selected and has experience with welding aluminum. I am checking their preliminary design to make sure it works. I am aware of the lower allowable stresses for welded aluminum in the HAZ, referencing the Aluminum Design...
Hello All,
I have an 8' x 8' platform I am designing with 6061-T6 aluminum channels, square tube perimeter, and diamond floor plate. The platform is not designed with support posts. It will instead be lifted and placed onto an existing ledge support on all 4 sides, like a cover. The assembly...
Hello Everyone! I am a structural engineer and work for an engineering firm that is looking into providing detailing services for structural steel and concrete rebar. We are considering Tekla Structures. My firm would like to provide these extra services to projects we have already designed...
Thank you, dik! I have some CISC references at work and didn't think to check them. Your references do shed more light on the partially composite beam analysis than I had before.
Hello everyone. I was wondering if I can get some guidance on a composite beam analysis task that I have. I have an existing steel beam (c. 1924 construction) that had shear connectors and a 5” concrete slab added to it during a renovation in 1981. I followed some design examples and referenced...
I am working on retaining wall structures (2 walls forming a containment area) where the load cases are dictated to be saturated soil to a level 3 ft. above the wall OR filled with water. I understand the soil pressures are calculated using Ra = 1/2 * ka * p.soil * g * H^2, where p.soil * g =...
I know about analyizing anything with a fixed end. But I need the boundary conditions to size my groove welds. Otherwise, yes, I would use 'simply supported' to analyze the plate. I ended up suming the point loads and putting that force on a small circular area in the center. I have to increase...
Thank you for the responses. I will have to look up the Timoshenko when I get a chance. I have tried the 'Uniform load over a small eccentric circular area of radius ro; edge fixed' in Roark's but I can't justify using it. I have 2 point loads and they are about 2-1/2 in. from the edges on a...
Hello All,
I have a flat circular steel plate that has 2 point loads (in the form of lugs) spaced symmetrically and along the centerline of the circle. The edge is fixed along the circumference. I had searched through Roark's 6th Edition to find examples of how to analyze the stress on this but...
Thanks! After working through the equations w has to be in lbs/in. Mr and Mt are simply in lbs, in my case. I don't know how that equates to the moments I am looking for. But on page 398, I can calculate the stress = 6M/t^2. That's psi or ksi in my case. M has to be in lbs. I just don't see how...
Ok that helps. The w is in lbs in my case (and in the equations). It is as if the FBD is a slice of the plate. The units make more sense to me now. And that takes care of the other questions because I am only concerned with the boundary values. Thank you again!
I'm wondering if someone could point me in the right direction. I'm designing a flat circular plate (fixed edges) with a uniform annular line load on it. I am using Roark's 6th Edition, Case No. 9b. I'm interested in calculating the bending moment at the center, bending moment at the outer edge...
I am having some trouble understanding how to apply Chapter Section H1.3 Doubly Symmetric Members in Single Axis Flexure and Compression. Below is my interpretation of that section. I could not find this section used in an example so I will provide some paremeters and my interpretation of what...
