83 
84 
85 
86 
87 
88 
89 
90 
oF 
COMPLEX STRESS DISTRIBUTIONS IN ENGINEERING MATERIALS. 211 
High carbon steels have superior endurance, thus agreeing with Nos. 23, 
48, 62, 90, 93. 
The effect of ‘rate of change’ of section of test pieces demonstrated, 
and the endurance of various forms (screwed, &c.) compared. See Nos. 
23, 74, 75 and 93. 
Strong evidence was found that the primitive elastic limits are fre- 
quently unstable under alternating stress; also evidence concerning the 
coincidence of the Wohler limiting range and the ‘ natural’ elastic ranges. 
See also, notably, No. 4. 
Fracture occurs by cracking in one of the localities where slip bands are 
massed together. Fracture goes through ferrite crystals, not only in iron 
(No. 27), but also in medium carbon steels. This is in accordance with 
Nos. 62 and 63. See also No. 66. 
The mode of fracture is the same whether the stress is applied directly 
or by means of bending (Nos. 62, 63). 
Stanton and 1908 The Resistance of Materials to Impact. ‘ Proc. Inst. 
Bairstow Mech. Eng.,’ No. 4, 1908. 
A machine for giving alternating direct impact is described. The blows 
of a tup put the specimen into alternate tension and compression. One of 
the chief objects of the research was to determine the limiting resistance 
of the materials for which the resistance to alternating stress had already 
been found. The important conclusion is reached that, if f is the ‘real’ 
elastic limit derived from the Wohler test, then the measure of tho 
? 
resistance to repeated small + equal impacts is a This result is con- 
firmed by Roos (No. 65). See also No. 51. 
Stanton and 1911 Experiments on the Strength and Fatigue Propertics 
Pannell of Welded Joints in Iron and Steel. ‘Proc. Inst. 
Civ. Eng.,’ vol. clxxxviii., 1911. 
Stead and 1903 Sorbitic Steel Rails. ‘Iron and Steel Inst. Journ.,’ 
Richards 1903, II., p. 141. 
Mentions rotating-bar (Wéhler type) tests on rails specially heat-treated. 
Do. : 1903 Restoration of Dangerously Crystallised Steel by Heat 
Treatment. Ibid., p. 119. 
Rotating-bar tests and heat treatment. 
Do. 1905 Overheated Steel. Heat Treatment; tests in Wohler 
machine, and also in severe bending. 
Thearle, S. J. P. 1913 Note on some Cases of Fatigue in the Steel Material 
of Steamers. Inst. Naval Arch., June 1913. Also 
*‘ Engineering,’ June 27, 1913. 
Tobusch, H. 1908 Elastic and Magnetic Hysteresis. ‘Ann. de Physik.,’ 
26,3. ‘Sci. Abs.,’ A, 1908, No. 1482. 
See Report, Appendix I. 
Turner, L. B. 1911 The Strength of Steel in Compound Stress and En- 
durance under Repetition of Stress. ‘ Engineering,’ 
July 28 to Sept. 8,191]. ‘Sci. Abs.,’ 1911, No. 1315. 
Bending Tests on cantilever specimens; one end fixed, the free end 
being made to describe a circle of constant small radius, 
Torsion Tests.—One end fixed, the other end twisted to and fro through 
a constant small angle. 
Speed, 250 cycles per minute. 
Materials.—Tube steel (annealed and untreated), mild steel, tool steel, 
and nickel steel (annealed and untreated). 
The main object of the research was to determine how far the shear- 
stress criterion of elastic failure applies to alternating-stress tests. The 
tests gave an affirmative result for tube steel and mild steel for both tension 
and torsion, and a negative result for tool steel and nickel steel. 
Unwin, W.C. 1905 Experiments on Rotating Bars at Different Tempera- 
tures. ‘Proc. Inst. Civ. Eng.,’ clxvi. ‘Sci. Abs.,’ 
1907, No. 373. 
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