On the concept of an equivalent column in the stability problem of compressed helical springs

Abstract

A more exact equivalent column for buckling of helical springs is introduced. It accounts for the pitch angle and possible buckling in two planes. Non-linear compression rigidity, local bending and shear rigidities as well as lower bounds for the mean values of these rigidities are established. The problem of anisotropy of buckling of helical springs is investigated in detail.