The Photoelastic Investigation of Three-dimensional Stress and Strain Conditions
A 1937 technical report from NASA's Technical Reports Server, a scientific study of photoelastic stress patterns in three-dimensional bodies, aimed at engineers and researchers. The pictures are black-and-white photographs of fringe patterns: concentric rings around loaded points, and banded, looping fringes across strips under load. A designer might take their bold concentric and wave-like banding as abstract graphic texture.
