Stress Analysis of Helical Coil Springs

Abstract

Many investigations have been hitherto reported as to the stress caused in coil springs. All of them, however, didn't take pitch angle or torsion of coil into consideration precisely. The authors have formulated, from Wittrick's formula, an analytical method applicable to coil springs with a large pitch angle and also confirmed its validity by experiments. The authors' investigation treated a case where the maximum principal stress occurs, contrary to the traditional concepts, at the surface of outer coil of spring.