Delta IV launch question

[Luke Pemberton]

A bending moment of 80,000 lb-ft was typical in a Saturn V flight.  When you look at the construction, the miracle is how something that looks so flimsy can be so frakking strong.

Am I correct in my understanding that the thickness of metal varied along the length of each stage which caused unique welding problems, which made it even more of a miracle that it stayed together?

[JayUtah]

Along the length and around the circumference, with resonances and varying elasticity in nearly every dimension in which vibration could occur.  This is why aerospace is the in high priesthood of both engineering and manufacturing.

[Luke Pemberton]

Along the length and around the circumference, with resonances and varying elasticity in nearly every dimension in which vibration could occur.  This is why aerospace is the in high priesthood of both engineering and manufacturing.

...and all designed without modern computers in the 1960s. I bet that was easy 

Would tensor analysis featured heavily in the design?

[JayUtah]

It featured heavier in the guidance math than in the vehicle design.  But yes, in the mid-1960s tensor analysis was one of the sexy mathematical techniques in high-end engineering.

[Luke Pemberton]

It featured heavier in the guidance math than in the vehicle design.

I'm guessing tensors would be used in guidance math to store and process the parameters that describe postion and motion. I have seen them used in rotational dynamics. Would they also have been convenient from the perspective of making efficient computing algorithms given how powerful tensors are? While notoriously horrendous, I would imagine that their functionality and the operations that can be carried out on them make them convenient and very powerful for computing.

But yes, in the mid-1960s tensor analysis was one of the sexy mathematical techniques in high-end engineering.

Sexy??? Sexy??? Have you momentarily lost your mind? Having ploughed through a course of general relativity, the words sexy and tensor were never used in the same sentence... ever!!!

[JayUtah]

While notoriously horrendous, I would imagine that their functionality and the operations that can be carried out on them make them convenient and very powerful for computing.

That's the thing.  Do the horrendous math on the chalk board in order to devise correct and simple control laws for the computer.

Sexy??? Sexy??? Have you momentarily lost your mind?

I'm channeling Dr. Elaine Cohen, one of my advanced math professors in graduate school.  That was her term for any technique or branch of mathematics that was especially powerful in what it could attain for practical purposes.

[Luke Pemberton]

I'm channeling Dr. Elaine Cohen, one of my advanced math professors in graduate school.  That was her term for any technique or branch of mathematics that was especially powerful in what it could attain for practical purposes.

Yes. Quite often ideas that are tricky to begin with prove to be extremely powerful and easier to use in the longer term. It is worth persevering. I found Lagrangian mechanics to be quite tricky when I first met it, but I put that down to the awful lecturing where we spent 3 lectures running through some esoteric mathematics. By that point I was switched off, but now understand the beauty and power of the Lagrangian. Anyway, this is running well off topic.

[scooter]

What an absolutely incredible discussion.
Where else would one find something like this....thanks to all.