Analysis of elastic-plastic deformations in screw threads by optical measuring methods

Two different optical methods to measure and evaluate deformations, load distributions, stresses and pressures in elastic-plastically deformed screw threads are presented in the paper. The evaluation of deformation in an original screw connection up to the plastic state is determined by speckle photography. Load distributions are evaluated. The determination of stress fields and pressures on an elastic-plastically deformed plane thread model of steel is realized by a special hybrid method, a combination of moire and FEM. The development of the normal stress on the contact flank is presented as one important result. (orig.)