Prediction of Stress Relaxation for Compression and Torsion Springs

摘要

An analytical technique was developed to predict the stress relaxation forcompression and torsion springs. The technique uses uniaxial tensile-generated stress-relaxation data for spring wires. Based on the tension-induced stress-relaxation data, the technique was applied to compression springs, where shear stress dominates in predicting the stress relaxation. This report documents the developed prediction method for stress-relaxation of compression and torsion springs and demonstrates the technique using experimental data. When applied to a V-band compression spring made of 302 stainless steel wire, a predicted 2.6% load reduction was obtained after 1000 hr loading as compared with the experimentally measured 2.1% load reduction. Since residual stresses play a significant role over the maximum operating stress range in compression and torsion springs, the calculation method of residual stress is also presented. (MM).