Ron:
Can you pass on to the team that looks after the VSIX for the Fortran to VS integration that in the latest VS 2022 Preview, the text editor turns on keyword completion and so it fixes everything, badly.
I found it and turned it off, but it would be better to turn it off in advance as they code the VSIX for this latest VS.
I use this version because my instruments talk C#.
The sun warming a bridge with almost zero traffic in Northern Iowa. 85 cps, the strain gauge picks up the data needed for a good FFT.
Over the years I have talked about ULARC the Plastic Analysis program from Powell's group at UCB circa 1970, I now have a bridge made in the 1930s that has pinned tension members and whilst ULARC's manual shows how to allow for them, the author allows you to directly code the stiffness matrix from input data, (he was a brilliant Fortran Programmer in 1970 - died young), I am now fixing the plastic analysis code to allow for a tension only member so it does not interfere with the rest of the analysis.
New term for the week, the engineering drawings show 21CB 85# as an example, CB is the term for a Carnegie Beam what we now call a W beam. I had to borrow a 1928 bridge design book from TAMU to find out. In 1929 they used simple statics to design the steel bridges.
It is a lot of fun.
Two seconds in the age of the universe, I understand what you said, but I cannot think of any physics or engineering experiment that would get to that level of data accuracy and be meaningful. Engineers are taught that this movement above is static.
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Jim:
To get permission to do something on the bridge is difficult, the paperwork is interesting the committees are endless.
I will try.
A bridge somewhere with the traffic, fairly standard acceleration. If you want to see a good analysis of this read Fryba's books, pity he died. (They all die - except this board). I have a number of Fortran programs from his ideas.
I had to zip the FFT.
From many measurements we know the world's bridges are degrading about 30 to 1500 microHz per day on the main frequencies, 30 is good, 80 is ok I am going to talk to the client about it and 1500 - tell the client I hope you do not want to be on CNN.
Assume it is concrete, the concrete is breaking slowly inside, so if we have an air bubble in the concrete the high point stress on the cement paste pops into the bubble, no one sees it, but the noise is at violin level, so we see the sort of high noise you see on the FFT.
Yes there are lots of other noise, but the working hypothesis is that some of the high level noise has meaning and one day we will get to it. Of course if you have a timber deck as in Brunel Bridge in England you have a lot of noise.
At the moment, the 80 is the issue not the 200 to 450 Hz, only so many days.
