function Ex33
    % Example 3.3 laminate stiffness as per section 1.15
    clc
    % G23 = E2/2/(1+nu23)  
    % Cprime (1.92) calculated with
    % http://www.cadec-online.com/Chapters/Chapter5/3DConstitutiveEquations
    % /StiffnessMatrix.aspx
    Cprime = [
    41032.17441    5271.194674    5271.194674    0    0    0;
    5271.194674    12122.37207    5507.041552    0    0    0;
    5271.194674    5507.041552    12122.37207    0    0    0;
    0    0    0    3307.66526    0    0;
    0    0    0    0    3405    0;
    0    0    0    0    0    3405
    ]

    theta = [45,-45,0,0,-45,0];
    thickness = [1,1,1,1,1,1];
    laminateThickness = sum(thickness);
    C = zeros(6);
    for i=1:length(theta);
        [T,Tbar] = RotationMatrix3D(theta(i));
        C = C + Tbar*Cprime*Tbar*thickness(i)/laminateThickness; % (1.102)
    end
    S = C^-1;       % (1.103)
    display(S);
    Ex  =1/S(1,1)   % (1.105)
    Ey  =1/S(2,2)
    Ez  =1/S(3,3)
    Gxy =1/S(6,6)
    Gyz =1/S(4,4)   
    Gxz =1/S(5,5)
    PRxy=-S(2,1)/S(1,1)
    PRyz=-S(3,2)/S(2,2)
    PRxz=-S(3,1)/S(1,1)
end
