What Magnitude(db) and Phase(deg) represent on Bode Diagram?
I am working on 2 DOF System and I want to understand some basic things.
%%Parameters
m1 = 2500; % (kg)
m2 = 320; % (kg)k1 = 80000; % (N/m)
k2 = 500000; % (N/m)b1 = 350; % (N*s/m)
b2 = 15020; % (N*s/m)%%Transfer Function
num1 = [(0) (-m1*b2) (-m1*k2) (0) (0)]; den1 = [(m1*m2) (m1*b1+m1*b2+m2*b1) (m1*k1+m1*k2+m2*k1+b1*b2) (b1*k2+k1*b2) (k1*k2)];G1 = tf(num1,den1); % G1(s) = (x1(s)-x2(s))/w(s)
Below you can see the Transfer Function and Bode Diagram results.
G1(s) = (x1(s)-x2(s))/w(s) Magnitude 26.4269 (dB) - Resonant Frequency 5.2493 (rad/s) Magnitude 2.2837 (dB) - Resonant Frequency 37.8886 (rad/s)
I can't understand what exactly these values mean.
For instance the first peak represent the vibration of the numerator x1(s)-x2(s) and the second peak the vibration of the denominator w(s)?
Magnitude(db) is the volume? the high level of vibration of my system?
Aim is possitive or negative Magnitude(db) for my system?
and what about Phase (deg)?
%%Parametersm1 = 2500; % (kg)m2 = 320; % (kg)k1 = 80000; % (N/m)k2 = 500000; % (N/m)b1 = 350; % (N*s/m)b2 = 15020; % (N*s/m)%%Transfer Functionnum1 = [(0) (-m1*b2) (-m1*k2) (0) (0)]; den1 = [(m1*m2) (m1*b1+m1*b2+m2*b1) (m1*k1+m1*k2+m2*k1+b1*b2) (b1*k2+k1*b2) (k1*k2)];G1 = tf(num1,den1); % G1(s) = (x1(s)-x2(s))/w(s)%%Bode Plot (Magnitude dB - Frequency rad/s)
bode(G1)grid on;
Best Answer