COMPLEX STRESS DISTRIBUTIONS IN ENGINEERING MATERIALS. 345 
On Certain of the More Complex Stress Distributions in 
Engineering Materials.— Report of Committee (Prof. E. G. Corr, 
Chairman ; Profs. L. N. G. Firon and A. Roperrson, Secretaries ; 
Profs. A. BARR, GILBERT Cook, and W. HE. Datsy, Sir J. A. Ewrne, 
Mr. A. R. Futton, Dr. A. A. GrirritHs, Prof. J. J. Guest, Dr. 
B. P. Haren, Profs. Sir J. B. Henperson, C. E. Ines, F. C. Lea, 
A. KE. H. Lover, and W. Mason, Sir J. E. Pretavet, Dr. F. Rogers, 
Dr. W. A. Scope, Mr. R. V. SourHwett, Dr. T. EK. Stanton, 
Mr. C. EK. Stromeyer, Mr. G. I. Taytor, and Mr. J. 8. Witson). 
Introduction. 
Tue Committee submit as their Report the following contributions embodying : 
(1) A report on Stresses.in Bridges; (2) accounts of recent researches on alternating 
stress; (3) further investigations on the Thermodynamic theory of fatigue and 
rupture; (4) an account of a new graphical method of obtaining the stress system 
in a plate from photo-elastic observations ; (5) a discussion of the stresses in reinforced 
pipes. 
I. The Stresses in Pipes reinforced by Steel Rings. By Prof. Gilbert Cook, D.Sc. 
II. The Graphical Determination of Stress from Photo-Elastic Observations. By 
Prof. L. N. G. Filon, F.R.S. 
II. Thermodynamic Theory of Mechanical Fatigue and Hysteresis in Metals. By 
Prof. B. P. Haigh, D.Sc., M.B.E. 
TY. Stresses in Bridges. By J. 8. Wilson and Prof. B. P. Haigh, D.Sc., M.B.E. 
VY. The Distribution of Stress in Round Bars under Alternating Torsion or Bending. 
By Prof. W. Mason, D.Sc. 
VI. The Repeated Bending of Steel Wire. By Dr. W. A. Scoble. 
The Committee ask for reappointment, with a grant of 501. 
Te 
The Stresses in Pipes reinforced by Steel Rings. 
By Prof. Grupertr Coox, D.Sc., King’s College, London. 
Is a contribution to the Report of this Committee for 1921 the author has given 
the results of a theoretical and experimental investigation of the influence of a flange 
on the stress distribution in a pipe under internal pressure. The close agreement 
between the calculated and observed stresses proved the method of analysis to be 
adequate for the purpose, and may justify its application to the analogous problem 
of the reinforced steel pipe. 
In large hydro-electric installations working under high heads the design of the 
pipe line presents considerable difficulties. For a given discharge and head at the 
power station, considerable economy in material is effected by increasing the size 
and reducing the number of the pipes, but in a plain welded pipe a limit is imposed 
to the size by the maximum thickness which can be satisfactorily welded, which may 
be taken to be about 14 inches. A type of construction recently introduced whereby 
large diameters may be used for high heads without an excessive pipe thickness 
consists in reinforcing the pipe by means of steel rings shrunk on at intervals along the 
pipe. The author has not been able to discover any published account of the method 
by which the strength of such pipes may be estimated. The investigation which 
follows has several points of interest, amongst these being the question as to the 
conditions undér which a reinforced pipe may be made lighter than a plain pipe 
