Project involves design and fabrication of support beam to provide temporary shoring of heavy equipment during a rigging and placement operation. As is often the case in heavy rigging the support beam will span across blocking. Any concerns regarding stability of the blocking? I am required to...
Does anyone have any reference or research literature for additional resistance factors for a specified corrosion allowance compatible with AISC design criteria?
ASME specifications have methods to handle a corrosion allowance. I have a structural specification and looking for a method other...
Risa 3D - Non-Building Structures Webinar
At the 52.19 mark in this video there is a discussion about interpreting the plate element results in comparison to code checks. This particular example was run with Allowable Strength Load Combinations, so the von Mises stress was compared to the yield...
For a situation with grillage beam assembly with several beams sitting cross wise on a carrier beam I have used rigid links connected between the centroid of the shapes to model the behavior. At the node that ties to the carrier beam I have released all moments as my initial attempt without...
I have read through many of the threads from 2007 to about 2013 regarding the implementation of the Dynamic Analysis Method and Risa 3D. I have done several example problems on this topic and would like to finalize my understanding of the current state of the software.
I have an application...
Imagine a single bay portal frame designed with rigid girder to column connections and base considered pinned. In reality the base is composed of a standard 4-bolt base plate connection to a concrete pedestal.
No leaner columns or additional frames for support. If the base plate is considered...
I am working on designing several large brackets to anchor to an existing concrete structure. The brackets are anchored to a wall near the top edge with design loads ranging from 50 kip, 100 kip, and 200 kip. Load is applied at approximate 12" eccentricity to the face of wall. Anchors must...
What happens when management is just ignorant?
After working at engineering company for several years I am realizing that a greater portion of our workforce knows very little about the engineering requirements in our designs. It appears that the engineering department has been stuck in a vacuum...
I have a fabrication that requires CJP welds for moment connections in a grillage type frame. (Basically welding two wide flange shapes perpendicular to each other.) The intended use of the fabrication is underwater and we typically call to seal weld all joints to minimize corrosion. The CJP...
When calculating anchorage forces for mechanical equipment, is the total design lateral seismic force, Fp, the actual numerical value to be used to determine the anchorage forces?
No other inclusion of Fp into load cases needs to be included. Now this is an ultimate load; so using LRFD...
If two motors of different size are compared in an existing installation - one larger and one smaller should not they both require the same power to perform the work unless there was a great difference in efficiency?
Therefore the current draw would be the same?
All motors are 3 phase / 460 V...
A consulting engineer has specified 3/4" DIA headed studs welded at a 45 DEG angle to a flat plate. I have searched and called around to our stud suppliers and they do not seem to have studs and ferrules available for this application. They suggest welding straight and then bending over. The...
I am writing to inquire for you thoughts on paint on embedded steel. I currently have two particular situations the first is a wide flange that is completely embedded in concrete. I have called for this item to not be painted. Consulting Engineer has questioned this item and has made reference...
Does anyone have a reference or derivation for basic allowable crane rail loadings?
Whiting Crane Handbook (p. 66,67)provides:
P = (A) X D X W
A = Varies between 1600, 1400, 1200
Manufacturers also list this value as a function of the Brinell Hardness.
D = Diameter of the wheel
W =...
See link below:
http://www.mi2g.com/cgi/mi2g/frameset.php?pageid=http%3A//www.mi2g.com/cgi/mi2g/press/210610.php
http://www.reuters.com/article/idUSTRE65L6IA20100622
Is there any technical credence to this? I would at least believe that buoyancy could be an issue?
Does anyone have a reference or derivation for basic allowable crane rail loadings?
Whiting Crane Handbook (p. 66,67)provides:
P = (A) X D X W
A = Varies between 1600, 1400, 1200 manufacturers also list this value as a function of the Brinell Hardness.
D = Diameter of the wheel
W = effective...
Does anyone have a reference which specifies the limits for columns with a slenderness ratio greater than 200?
I have read several of the column posts and have referenced most of my textbooks and the best information I have found states "columns bounded by l/r < 200".
I have a safety factor...
See attached sketch of simple frame in a single plane. No other support is provided out of plane. Frame is part of machine equipment with force applied to the horizontal framing member that acts bidirectional in the vertical direction. Magnitude is 100,000 lbs. Now for basic analysis in...
I realize there are numerous discussions regarding this and I have read most of the threads. The thread below is close to what I am looking for.
http://www.eng-tips.com/viewthread.cfm?qid=147500&page=3
I am in a similiar situation, currently working mainly in AutoCAD creating 2-D drawings of...
I have a casting with an 1.25" DIA hole that has been drilled 1" from its correct location. The assembly consists of mating flanges and the mating component has already been machined correctly. The section thickness at this point is approximately 8". Material is ASTM 126 CL B. If the section was...
