53 
56 
57 
58 
COMPLEX STRESS DISTRIBUTIONS IN ENGINEERING MATERIALS, 207 
stroke than the (unfixed) end of the specimen engaging with it. The length 
of the slot could be varied so as to give various proportions of impact (?) 
with the bending. The stroke of the die could also be varied. 
Speeds, 150 to 700 (double) strokes per minute. 
Specimens, $ inch diameter and 8$ inch long. 
The maximum stresses were higher than the tensile elastic limit. 
Material, cold rolled steel, carbon 0-1 per cent., annealed at a red heat. 
Within the limits of the experiments it was found that the endurance 
was independent of the proportion of the ‘impact’ factor in the bending. 
It is doubtful whether there was any dynamic effect at all at the moment 
of highest stressing. See Nos. 65 and 83. The nature of the surface of the 
specimen, whether turned, filed, or ground, had a marked effect. The 
polished and the ground specimens showed an increased resistance over the 
turned ones of 45 per cent. to 50 per cent. See also No. 23. 
An attempt is made in a second paper (Int. Cong. for Testing Materials, 
1912) to find the stresses in the above experiments by observation of the 
strains (beyond the elastic limit) and stresses in static bending tests, and of 
the strains and stresses in a tensile test of the same material. 
Lenoble, E. 1900 Permanent Deformation of Metallic Wire (Hysteresis 
Loop). ‘Journ. de Physique,’ 9, Oct. 1900. ‘ Sci. 
Abs.,’ 1901, No. 7. 
A hysteresis loop was obtained for a wire which was gradually loaded 
and unloaded. 
Lilly, W. E. 1910 A New Torsion-testing Machine. ‘ Proc. Inst. C.E. 
of Ireland,’ Nov. 2, 1910. 
A machine for direct and reverse torsion worked by hand ; stress strain 
diagram automatically drawn. 
Do. 1911 The Elastic Limits and Strength of Materials, ‘ Proc. 
Inst. C.E. of Ireland,’ Dec. 6, 1911. 
An account of some experiments on the machine of No. 53. The results 
are believed by the author to confirm Bauschinger’s theory. 
McCaustland, 1906 Effect of Low Temperature on the Recovery of Steel 
: from Overstrain. ‘Am. Soc. Min. Eng, Bull,’ 9, 
May 1906. ‘Sci. Abs.,’ 1906, No. 1176. 
The results are similar to those of No. 17. 
Memuler, K., 1910 Temperature Measurements during Repetition of Stress ; 
and experiments with Pipes. ‘Kgl. Material-Priifungs- 
Schob, A. amt. Mitt.,? 28, 6, pp. 307-33. ‘Sci. Abs.,’ A, 
1910, 1382. 
See Report, Appendix I. 
Milton, J. T. 1905 Instit. of Naval Architecture, July 1905. Milton 
mentions cases of failure of plates by fatigue. Also 
‘ Engineering,’ Aug. 4 and 11, 1905. 
Pearson, Karl 1905 On Torsional Vibrationsin Axles and Shafts. ‘ Drapers’ 
Company Memoirs,’ Technical Series IV. 
It is suggested that there may have been much higher stresses than those 
calculated in Wohler’s tests with + alternate stresses, because the loadings 
were repeated before the stress-waves set up by the previous loadings had 
ceased to be of importance. Thus the real maximum stresses would be 
the sum of effects due to several successive loadings. Since L. Bairstow 
(No. 4) has obtained results corresponding quantitatively to Wéhler’s (about 
60 per minute), with a rate of loading of only two per minute, it seems probable 
that stress accumulation can only have been a very minor factor in Wohler’s 
results. Supposing a small number of successive peaks of stress to occur, 
the duration of the peak stresses would be very short and unlikely to give 
appreciable non-elastic strain (see No. 43); and moreover, though such 
non-elastic strain (cleavage slipping) may be produced, yet, unless the stresses 
producing these strains are many times repeated, cracking in the crystals 
would not be produced (No. 82). The fact of possible stress accumulation 
