from table 1.1

F1t = 1830 MPa

F2t = 57 MPa

F6 = 71 MPa

8.4151 < 1830

6.5849 < 57

3.4151 < 71

Safety factor = 57/6.6 = 8.636

Appendix

Pb 5.2

clear all clc %% 5.2 Sx=10; Sy=5; Sxy=2.5; theta=60; sigma=[Sx;Sy;Sxy]; C= cosd(theta) ; S=sind(theta); T=[(C^2) (S^2) (2*S*C); (S^2) (C^2) (-2*S*C); (-C*S) (S*C) ((C^2)-(S^2))] sigma_dash=T*sigma

Pb 5.3

clear all clc %% 5.3 theta=45; E1=35; E2=3.5; G12=1.75; neu12=0.3; neu21=0.3; C= cosd(theta) ; S=sind(theta); T=[(C^2) (S^2) (2*S*C); (S^2) (C^2) (-2*S*C); (-C*S) (S*C) ((C^2)-(S^2))] delta=1-(((neu12)^2)*(E2/E1)); Q=[(E1/delta) ((neu12*E2)/delta) 0; ((neu12*E2)/delta) (E2/delta) 0; 0 0 G12] Q_bar=inv(T)*Q*T

Pb 5.5

clear all clc %% 5.5 theta=10; w=0.01; l=0.15; t=0.002; F=200; E1=35; E2=3.5; G12=1.75; neu12=0.3; neu21=0.3; A1= w*t A2= l*t A12=l*w sigma1=F/A1 sigma2=F/A2 sigma12=F/A12 sigma_dash=[sigma1; sigma2; sigma12] C= cosd(theta); S=sind(theta); T=[(C^2) (S^2) (2*S*C); (S^2) (C^2) (-2*S*C); (-C*S) (S*C) ((C^2)-(S^2))] delta=1-(((neu12)^2)*(E2/E1)); Q=[(E1/delta) ((neu12*E2)/delta) 0; ((neu12*E2)/delta) (E2/delta) 0; 0 0 G12] S= inv(Q) B=inv(T) S_bar=B*inv(Q)*T sigma=B*sigma_dash epslon=S_bar*sigma epslon_dash=S*sigma_dash