I am running through some calculations on an aluminum structure. In the longitudinal direction it is a braced frame and the lateral direction it is a moment frame. The frame is not the typical column/ beam connection. The column I believe would be what they refer to as a lean to. Where it is a...
I have a situation where the one side of a fabric building wall is seeing suction when the exhaust fans are running. The wall seeing the suction is opposite of the exhaust fans. There is a hybrid system being used in that the supply is natural and the exhaust is mechanical. I feel like the...
I have a contractor telling me that I am responsible as the structural engineer for determining if we can switch from a IIB construction type to a IIIB. Is this correct, I see this as an architectural item, aside for designing the structural members for any loading due to fire.
We currently have a building that is classified as a construction type IIB, the client wants to change it to a IIIB because he has another structure sitting 5ft away that has a type IIIB classification. The code official told him to just make our building (IIB) a IIIB structure my question stems...
I have a connection where a 3" long cantilevered plate is loaded 2.5" out causing a moment force on the connection point. The connection point is a round tube that sits between two other round tubes. There is one bolt that makes the connection. So the connection appears to be a pinned connection...
I have a question regarding Thermal breaks on Steel buildings. I am not sure if a mechanical engineer usually deals with this but since it affects R values and hvac performance I figure that it would be a HVAC topic. If you have a steel building with roof and walls with R values of r-30, instead...
I was hoping soemeone could point me in the direction of where in ASHRAE does it dictate free air space requirment calculations. I ran the calcs for CFM but the client wishes to install a passive system. So the CFM calc means nothing, right?
CFM = Volume *3/60 (3ACH/60min/hr) = 80CFM
My international supplier is substituting S355 for A572 grade 50 that was originally specified. I am running through the properties and noticed that the S355 has higher Mn, Si, Cu and N values at 1.6%, .55max,.55max,.012max (respectively) compared to 1.35%, .40,0,0.
I believe this is a...
I am reading through the AISC360 Section M5.5 Identification of steel and it states that "The fabricator shall be able to demonstrate by a written proceduer and by actual practice a method of material identificaion, visible at least through the fit up operation, for the main structural elements...
I have a fabric structure that consists of aluminuim material. It is an arched moment frame in the transverse direction and a braced frame in the longitudinal direction. There are rectangular tubes used as braces between the arches.
I have several questions on this. First the arch member is...
I have a frame where the axial header (horizontal member) is connected to the beam/column (vertical member). The connection consist of a simple shear connection at the web of the horizontal member and a more rigid (3 bolt) face plate connection to the vertical member. Is there guidlines used to...
I am looking for some clarity on Section F2 of the 13th edition of the AISC. I am designing a compact I shape with the Mn/omega = FyZx for yielding and my unbraced length lies between Lp and Lr. It is a simple beam with governing wind loads applied to the strong axis.
Reading further...
I have recently heard of fillers being used in oversized holes but am not familiar with this application unless they are speaking of plate washers or finger joints. Are there other techniques to fill an oversized hole, in order to transfer shear?
I have been reading alot about welding for cold formed memebers (11 and 13 gauge)have found that they recommend GMAW,SMAW and FCAW. I also read in AISC 13th edition that fillet welds do not prequalify for GMAW. I have some shop dwgs with fillet welds shown all over the cold formed connections...
I believe ASTM F 844 is one of the standard washer types, however, as I was reading up on this washer it does say that the engineer must approve of this type of washer. Could anyone inform me of the differences between this washer and the other standards. The only think I have found thus far is...
I have been going through some calculation sets where I have found in the longitudinal direction wind design the end condition values were overlooked. Is there a resonable explaination for ommiting these values on a MWFR building.
One explanation the engineer offered is that the building is...
I recently had an engineer question me on a building that is being installed at an international airport on backwash wind design. I am not sure how to approach this.
The building is designed for the correct windspeed and exposure C. The only other factors that I could take this issue into...
I have two instances where I have an oversized hole with a bolt that is 1/4" to 3/8" oversized. The first is an anchor hole, there is a 3/4" bolt in a 1 1/8" hole. If I have checked the bolt and base plate to resist the shear, fatigue is not an issue due to the low frequency of the building and...
I am specifically looking to know this for the state of NY but would like to know in general where do I look to find this information? I already tried the NY DOB and didn't find anything.
Thanks
I have a 100x160ft long 1 story fabric building located in Watsonville California. I am trying to compare the base shear from the seismic analysis to wind design. I have a value of 16426.7lb for seismic and 54510.4lb for wind. This seems impossible to me. I thought that in that area seismic...
