How Can I write a code that could plot a Fourier series formula ?

Hi All

I have attached the formula ,that I wanted to plot w(x,y) , I tried to write a little bit of it , but I am stopped somewhere , if you have any suggestion :

x and y are variables .

here is what I have written so far :

p= 160;

D11=41.0565252087;
D12 = 137.5842503284;  
D22=0.2404353556; 
D66=0.1487221935;

a=2 ;
b=3;

w=0;
x=[0:0.1:a];
y=[0:0.1:b];
for m = 1:2:5
    for n = 1:2:5
        for x =0:0.1:a
            for y =0:0.1:b
        w[?] =  1/(m*n)*sin(m*pi*x/a)*sin(n*pi*y/b)/(D11*(m/a)^4+2*(D12+2*D66)*(m/a)^2*(n/b)^2+D22*(n/b)^4);
    end
end
end
end

I know the end commands are not placed well