loop modal summation to this programme i writ one but maybe it's not appropriate

M=120; EI=20*10^7; ksi=0;%.04; k=0.2*10^8; v=1; n1=5; n=501;

l=(3*pi/2)*(4*EI/k)^0.25; t1=l/v; %%%%%%%%%%%%%%%% Les conditions initiales %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

v_0=0.001; %m/s;vitesse initiale T_0=0.0001; %m déplacement initiale t1=l/v; ww1=0; Q=16*10^4; %N; chargement

for m=1:n1; for i=1:n; xx(i)=l/(n-1); xx1(i)=xx(i)*(i-1);

phi(i,m)=sin(m*pi*(xx1(i))/l);

   for j=1:n;
               tt(j)=l/v/(n-1);
             tt1(j)=tt(j)*(j-1);
w_d(m)=(((((m^4)*(pi^4)*EI)/M/(l^4)))+k/M)^0.5;

%ksi(m)=c/(2*M*w_d);

w_n(m)=w_d(m)*(1-(ksi)^2)^0.5;

B=T_0;

mu(m)=m*pi*v/l;

A1=2*Q/(M*l);

A2(m)=1/(w_n(m)^4+2*(((ksi*w_d(m))^2-w_n(m)^2)*mu(m)^2)+mu(m)^4); %(((w_n(m))^4)+2*((((ksi*w_d)^2)+((w_n(m)^2)))*(mu(m)^2))+mu(m)^4);

A3(m)=2*ksi*w_d(m)*mu(m);

A4(m)=(mu(m)/w_n(m))*(((ksi*w_d(m))^2)-(w_n(m)^2)+mu(m)^2);

A5(m)=((w_n(m))^2-(mu(m)^2));

T11(j,m)=exp(-ksi*w_d(m)*(tt1(j)));

T1(j,m)=A1*A2(m)*(T11(j,m)*(A3(m)*cos(w_n(m)*tt1(j))+A4(m)*sin(w_n(m)*tt1(j)))-A3(m)*cos(mu(m)*tt1(j))+A5(m)*sin(mu(m)*tt1(j)));

ww1(i,j,m)=phi(i,m)*T1(j,m);

   end
  end
end

for i=1:n; for j=1:n; ww1(i,j)=0; for m=1:n1; ww1(i,j)=ww1(i,j)+ww1(i,j,m);

%ww1(i,j) = sum(ww1(i,j,:));

        end

    end
end
plot(ww1(:,3),'b');
 hold on