The idexing for frequency and residual torque, variable w and S starts from 1 to 1000 and from 2 to 11 resepctively.
So I think the indexing is incorrect.
Try to revise the indexing as follows:
for i=1:1000
w(i)= 0.2*(i-1);
a(1,i) = 1; %Amplitude (assume)
T(1,i) = J(1)*a(1,i)*(w(i)^2); %Torque
S(1,i) = T(1,i); %Residual Torque on 1st member
for n=2:11 %Members 2 to 11
a(n,i) = a(n-1,i) - (J(n-1)*E(n-1)*a(n-1,i)*w(i)^2);
T(n,i) = J(n)*a(n,i)*w(i)^2;
S(n,i) = S(n-1,i) + T(n,i);
a(n,i) = a(n-1,i) - S(n-1,i)*E(n-1); %a(n) = (sum of preceding res torques)*Flexibility
end
end
plot (w,S(11,:));
xlabel('Frequency (Rad/s)');
ylabel('Residual Torque');
