ON STRESS DISTRIBXrriONS IN ENGINEERING MATERIALS. 281 



to test the applicability of Guest's law with regard to elastic limits, plastic 

 limits, and ultimate strengths, for each of which breakdown points the 

 tension and compression stresses should according to Guest's law be 

 equal and twice as great as their combinations : the shearing stresses. 



Ultimate Strengths. Table I. 

 The ultimate crushing strengths were not obtainable. The ordinary 

 tensile strengths, T, were obtained by the usual method of dividing the 

 original cross-section of the samples into the maximum loads recorded 

 during the tests. The tenacities per reduced section, T„ were, as the 

 name implies, obtained by dividing the reduced section of the sample, 

 at the point of fracture, into the smallest recorded load at the moment 

 of fracture. On account of the unsteady conditions near the moments 

 of fracture it was not always possible to determine these loads with 



Table I. 

 Ultimate Strengths. 



Ultimate 

 Tenacities 



D 

 A 



M 

 X 



u 

 p 



s 



B 



T 



L 



BB 



N 



E 



J 



Q 



V 



z 



F 



K 



G 



R 



W 



II 



C 



Y 



Esti- 

 mated 



Tons 



23-78 

 24-22 

 2518 

 25-38 

 25-94 

 26-33 



26 56 



27 31 

 27-33 

 27-40 

 27-43 

 27-57 

 27-57 

 27-85 

 28-81 

 28-90 

 28-97 

 2951 

 29-94 

 30-66 

 31-26 

 31-59 

 32-60 

 33 84 

 37-69 



Ob- 

 served T 



Tons 



23-60 



24-11 



24-90 



24-60 



25-30 



25-50 



26-00 



27-40 



28-20 



26-30 



27-60 



26-27 



30-60 



28-10 



28.50 



29-60 



29-70 



28-90 



27-80 



31-30 



32-10 



31-80 



33-70 



33-30 



37-40 



Tenacities per 

 Eeduced Sections 



Ultimate Shearing 

 Strengths 



Esti- 

 mated 



Tons 



40-20 

 48-16 

 53-96 

 50-52 

 49-66 

 54-64 

 54-24 

 52-52 

 .54-10 

 56-32 

 54-32 

 55-38 

 51-28 

 54-14 

 54-76 

 54-70 

 55-72 

 58-78 

 .55-02 

 57-84 

 60-68 

 57-48 

 58-40 

 55-76 

 68-58 



Observed 

 T, 



Tons 



36-57 



50-48 



58-22(- 



48-17 



53-12 



56-74 



53 33 

 56-24 

 62-62(- 

 60-56(- 

 51-20 

 58-62(- 

 58-42( 

 67-86( 

 68-77 

 54-88 

 49 33 

 57 00 



54 96( 

 60-88 

 62 80 

 61-26( 

 64-81( 

 51-72( 

 66-96 



Esti- 

 mated 



Ob- 

 served S 



Tons 



20-72 

 27-44 

 24-42 

 23-12 

 23-29 

 24-50 

 24-54 

 2510 

 24-42 

 25-39 

 24-44 

 24-85 

 24-45 

 24-63 

 25-06 

 24-79 

 24-94 

 27-10 

 25-33 

 25-85 

 27-35 

 25-90 

 26-65 

 25-73 

 28-97 



Tons 



S/T 



S/Tr 



21-23 

 22-00 



21-05 

 22-86 

 24-10 

 22-90 

 24-90 

 25 72 

 24-40 

 23-34 

 2372 

 23-12 

 24-85 

 29-93 

 25-00 

 24-74 

 26-60 

 25-15 

 27 -.50 

 27-65 

 27 11 

 28-37 

 26-41 

 29 70 



0-90 

 0-91 



0-86 

 0-90 

 0-95 

 0-88 

 0-91 

 0-91 

 0-93 

 0-85 

 0-90 

 0-76 

 0-89 

 0-91 

 0-85 

 0-83 

 0-92 

 0-90 

 0-88 

 0-86 

 0-85 

 0-84 

 0-80 

 0-79 



0-58 

 0-44 



0-44 



0-43 



0-42 



0-43 



0-44 



0-41( + ) 



0-40(-f) 



0-46 



0-40( + ) 



0-40(-f) 



0-36(+) 



0-44 



0-46 



0-50 



0-47 



0-46{ + ) 



0-45 



0-44 



0-43(-f) 



0-44(-f) 



0-5m-) 



0-44 



The above estimated stresses are found by the formulae 



T, =19-75 + 25 (C + C^) + 11 5 Si + 30 P + 205 N - 115 S + 36 5 As 

 T, =50-5 + 20 C +20 Si + 40 P + 200 N - 80 S 



S =22 2 + 9 C +6 Si + 20 P + 100 N - 20 S. 



(— ) These stresses may be too high. (+) These ratios may be too low. 



