I wanted to know if anyone knows about any tests of WWII fighters that measured the actual wing bending while making horizontal sustained turns, roughly around the 3 G range or more, at various power levels or speeds.
I have been told about cockpit strain gauges, and would like to know how they work and how they are calibrated.
Wing bending tests of WWII fighters on the ground are also of interest, especially how they are used to calibrate the cockpit strain gauge.
I wanted to know if anyone knows about any tests of WWII fighters that measured the actual wing bending while making horizontal sustained turns, roughly around the 3 G range or more, at various power levels or speeds.
I have been told about cockpit strain gauges, and would like to know how they work and how they are calibrated.
Wing bending tests of WWII fighters on the ground are also of interest, especially how they are used to calibrate the cockpit strain gauge.
There are dozens of papers - both theoretical and practical - in the NACA archives on wing deflection, twist and the poroperties of various materials under load
Tensile elastic properties of typical stainless steels and nonferrous metals as affected by plastic deformation and by heat treatment NACA UK Mirror report description page
The effect of methods of testing on the ultimate loads supported by stiffened flat sheet panels under edge compression NACA UK Mirror report description page
The tensile elastic properties at low temperatures of 18:8 Cr-Ni steel as affected by heat treatment and slight plastic deformation NACA UK Mirror report description page
1944
The influence of the aerodynamic span effect on the magnitude of the torsional-divergence velocity and on the shape of the corresponding deflection mode NACA UK Mirror report description page
I recently learned they could not record wing bending data (with a "strain gauge") while in flight before or during WWII, and it follows from this that all the wing bending data from the 1940s and perhaps well beyond was thus obtained on the ground...
I would say that pretty much elliminates any notion that they really tested what is going on as to the actual wing-bending in flight of these old single-engine aircrafts unless flying tests have been done on them since... This is highly doubtful for nose-driven aircrafts, which tend to be light lower-development cost aircrafts, or just very old and flown by the book in flying museums...
I was very specific in what I wanted, and none of the above links are in any way relevant: The technology to record what I described in flight was probably barely available in the 1960s, or the 50s at best, by which point the aircrafts I am interested in were already museum pieces...
Also, contrary to what I was led to believe, there was never any wing strain gauge instrument in the cockpit of a small prop aircraft: The data is recorded to be deciphered later, assuming that ever was done for very small prop aircrafts in the first place.
In addition to all of the above, strain gauge results obtained on the vertical plane are irrelevant. Only sustained horizontal turns data matters.
I think you will find that it wasn't a case of 'could not record wing bending data (with a "strain gauge") while in flight before or during WWII' but more a 'chose not to put strain guages into the cockpit of WW2 aircraft'.
I read a report on this topic some time ago and the author asked why hadn't they put these into WW2 aircraft and was told that it wasn't deemed a priority.