It seems that you're trying to plot the transmissibility (T_d) as a function of the frequency ratio (r) for a single degree of freedom (SDOF) system subjected to harmonic base excitation. There are a few issues in the code that need to be corrected:
- You are redefining r after initially setting it up as a vector of frequency ratios.
- You are redefining zeta after initially setting it up as a vector of damping factors. You should use this vector to compute the transmissibility for each damping factor and frequency ratio.
- You are trying to plot Td for multiple values of zeta and r without using a loop or vectorized operations.
- The plot command should be inside the loop where you calculate Td for each damping factor.
m = 10; % mass [kg]
k = 100; % stiffness [N/m]
omegan = sqrt(k/m); % natural frequency
zeta = [0.05; 0.1; 0.15; 0.25; 0.5; 1.25; 1.5]; % damping factors
r = 0:0.01:3; % frequency ratio
figure;
hold on; % hold the plot for multiple curves
for i = 1:length(zeta)
Td = sqrt((1 ./ (1 - r.^2).^2) + ((2 * zeta(i) * r) ./ (1 - r.^2)).^2); % displacement transmissibility
plot(r, Td, 'DisplayName', ['\zeta = ' num2str(zeta(i))]);
end
xlabel('Frequency ratio (r)');
ylabel('Transmissibility (T_d)');
legend('show');
hold off; % release the plot hold
This code will plot the transmissibility (T_d) for each damping factor zeta as a function of the frequency ratio r.
