6-16 DESIGN OF LAMINATES 



From Fig. 6-10 

 El 



El, 



= 0.575; Ex = £30° = 0.575 x 2.U6 x 10 6 = l.la5 x 10 6 psi 



— = 1.850; G 12 = G ^0° = 1 -^° x 0.520 X 10 6 = 0.962 x 10 6 psi 

 G LT 



°12 = °30° = 0.558 

 m-L = 0.830 

 m 2 = - 0.830 

 Strains caused by compressive stress f-j_ = 15000 psi are 



£-,= w- = — 1^000 = 0.0IO6 in. (strain in 1 direction) 



1 E l l.Lil5 x 106 



e 2 = " o 12 £]_ = -0.558 x 0.0106 = -0. 00592 in. (strain in 2 direction ) 



v nn = -m-, -1 = -0.330 x — 1 ^ 000 — r = - .00506 in. (shear strain) 

 12 E L 2.h6 x 10 6 



Strains caused by shear stress T i_ 2 = 5000 psi are: 



Y = lii = 5000 = .oo520 in. 



Y 12 G 0.962 x lOO 



e-, = -m-, J£ = -0.830 x ^000 £_ = -O.OC169 in. 



- 1 1 E t 27C6 x 10° 



e = - m? li£ = -0.830 x - 000 _ = + 0.00169 in. 



E T 2.1.i6 x 10 6 



L 



Total Strains are: 



K l +e l = - olo6 ° " COOI69 = + 0089 in. 

 e 2 +e 2 = - 0.00592 + 0.00169 = - 0.00U2 in. 

 Y 12 + Y 12 = - 0.00506 + 0.0052 = 0.01026 in. 



