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
    E1  = 37.88E3;
    E2  =  9.407E3;     E3  = E2;
    G12 =  3.405E3;     G13 =  G12;
    nu12=  0.299;       nu13=  nu12;
    nu23=  0.422;
    G23 = E2/2/(1+nu23);
    
    % (1.104)
    Sprime = [
        1/E1, -nu12/E1, -nu13/E1,0,0,0;
        -nu12/E1, 1/E2, -nu23/E2,0,0,0;
        -nu13/E1, -nu23/E2, 1/E3,0,0,0;
        0,0,0,1/G23,0,0;
        0,0,0,0,1/G13,0;
        0,0,0,0,0,1/G12];
        
    Cprime = Sprime^-1;

    theta = [45,-45,0];
    thickness = [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)
    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
