In the previous paper, we reported on our experiments about the coiled springs of steel wire under pulsating compressive load (mean compressive stress τm is equal to stress amplitude τa). In the present tests, the fatigue strength and the deformation due to fatigue were obtained with regard to the cases when various mean stresses were applied. Further, the creep deformation under static load was obtained and compared with that under repeated load.
The results were as follows:
(1) A residual shear strain of coiled springs under repeated compressive load was largest in the pulsating test (τm=τa) and became lower in proportion to an increase of mean stress, but little variation was observed where τm/τa=0.6.
(2) Fatigue limit (Maximum stress) got higher with an increase of mean stress.
(3) A stress amplitude at endurance limits decreased showing a straight line in accordance with addition of mean stress, and that in a deformation limit did not vary on the whole as if it were constant when τm/τa=1-0.6, but began to decrease rapidly when mean stress was made beyond such a range.