Originally Posted by
stressmerchant
Thanks for some good info - I remember the drawing offices at my old work filled with lots of boards and hard working men and women. No computers ;-)
My impression is that the CAD tools sometimes separate us from the reality of design. The old designers may not have had the fancy software, but they had a lot of common sense behind them. I battle daily with young engineers who will blindly believe the numbers that the computer spits out.
A few recent gems:
"I don't care what the flight test results say, my prediction is correct. I looked up the formula in Roskam and I've double checked my maths!"
"OK, so we designed to the finite element predictions, and the finite element overpredicted the stresses by 50%. At least we know the structure is strong enough".
"Yes, but it's overweight"
"And the problem is??"
"But the diagonal tension field didn't show up on NASTRAN, how am I meant to know about it? "
Children of Magenta?
Anybody else ever come across a dH era structures professor called Dennis Mead at Southampton? I recall him once saying in a lecture "The trouble with aerodynamicists is that the can assume absolutely anything, except for responsibility".
When I ran an airworthiness office I was often presented with elaborate FE predictions built upon sand. If all else fails, my standard response was "thanks, that's given me confidence that we can now go and build and test a sample structure to destruction on your budget".
The other classic quote there was "The difference between theory and practice? In theory it's right, in practice it isn't."