WWII single engine fighter wing bending while in flight measurements

[Gaston]

Hello everyone.

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.

Thanks in advance.



Gaston

[Jabberwocky]

Hello everyone.

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.

Thanks in advance.

Gaston

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

Some of the more relevant

1939

Acceleration, stress, and deflection measurements on the XB-15 bomber in gusty air
NACA UK Mirror report description page

Comparison of theory with experiment in the phenomenon of wing flutter
NACA UK Mirror report description page

Experimental and analytical investigation of a monocoque wing model loaded in bending
NACA UK Mirror report description page

1940

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

Structural tests of a stainless steel wing panel by hydrostatic loading
NACA UK Mirror report description page

The frequencies of cantilever wings in beam and torsional vibrations
NACA UK Mirror report description page

1941

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

Stresses and deflections in thin shells and curved plates due to concentrated and variously distributed loading
NACA UK Mirror report description page

Tests of a gust-alleviating wing in the gust tunnel
NACA UK Mirror report description page

An analytical study of wing and tail loads associated with an elevator deflection
NACA UK Mirror report description page

1942

Bending of rectangular plates with large deflections
NACA UK Mirror report description page

Flutter calculations in three degrees of freedom
NACA UK Mirror report description page

Square plate with clamped edges under normal pressure producing large deflections
NACA UK Mirror report description page

Square plate with clamped edges under normal pressure producing large deflections
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


ect
ect
ect

[Gaston]

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.

Gaston

[Glider]

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.