// Pb-5-11
// cd 'C:\Users\EJB\OneDrive\Books\ICMD_3e\solman'
mode(0) // prints every line not suppresed by ; as MATLAB
// from Pb 5.5
E1 = 35E3;    // MPa
E2 = 3.5E3;
v12 = 0.3;
G12 = 1.75E3;
G23 = 0.35E3;
v21 = v12*E2/E1;
D = 1-v12*v21;
Q = zeros(3,3);
Q(1,1) = E1/D;
Q(2,2) = E2/D;
Q(1,2) = v12*E2/D;
Q(2,1) = Q(1,2);
Q(3,3) = G12
// from Pb 5.9
theta = 45
m = cosd(theta);
n = sind(theta);
R = [[1 0 0];[0 1 0];[0 0 2]];
T = [[m^2 n^2 2*m*n];[n^2 m^2 -2*m*n];[-m*n m*n m^2-n^2]];
Q_bar = T^-1*Q*T'^-1
// Pb 5.11
t = 2;   //mm
w = 10;  //mm
A = t*w;    //mm^2
N = [200,0,0]';   // N
sigma = N/A  // MPa laminate cs
// calculate Lte strains
eps_ = Q_bar\sigma //solve [Q_bar]{eps}={sigma} in Lte cs
// transform to lamina cs
epsp = R*T*R^-1*eps_ //(5.42)



