Design and Stress Analysis of Extraterrestrial ... - The Black Vault

The element is in plastic state (1 = 0.5):
-,=-y
T ax + e + ,.
__ 2 2 1/2Z
-. *=t
-':,+~~.,
(S.,O.G-,)
£ . . --'-t
(-÷+0,5". .
3 '1
(1.30)
Example 1.2. Find the equivalent stress for three stressed
states indicated in Fig. 1.32. Stresses are given in daN/cm 2 .1
Material under extension and contraction operates identically (k - 1).
The value of equivalent stress according to formuaa (1.27) is
a) -g=800-100=700; (=POO, C? = 300, 03 = 100);
b) :i=C00•--!-(-100)= 700 (-1=6'W0, C2=0. o3=--100);.
c) ai=750-0=750; (:1=750, a,=`.00, oj=O).
The value of equivalent stress. according to. formula ,(i..8) is
Cj= I 0,5 ((1 i-a2)27- ( a2- 1)2 -- (a3- aj)2j;
a ) o = ]0,5 ((800 -- 3)0~)2 + (300 - 100). + (IOU - 800)21 =623;
b) € = J 0,5 [(WO0 -- 0) + (0- 100)2 + (_ 100 =TO00)2fJ= 654;
c) -ot = J/0,5 [(750- 0)4 + (100-0)•2 + (0 -- 750)2] = 805.
As seen from the example, the values of equivalent stresses,
,caiculated according to different .strength theories, are not the,
same.
*1 daN = iON; 1 daN/cm 2 = 1000 N/m 2 = 1 kN/m 2 .
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