vtb5_5

vtoolbox3.5是振动数值模拟工具箱

function vtb5_5(ma,m,ca,ka,k,rfin)

%VTB5_5 Normalized amplitude of the primary mass for a 

%damped vibration absorber design.

% VTB5_5(ma,m,ca,ka,k,rfin) plots the normalized amplitude

% for a system with the parameters:

%  ma    = absorber mass

%  m     = primary mass

%  ca    = absorber damping coefficient

%  k     = primary stiffness

%  ka    = absorber stiffness

%  rfin  = maximum normalized frequency for the plot



%calculate variables for equation 5.37



wa=sqrt(ka/ma);

wp=sqrt(k/m);

b=wa/wp;

mu=ma/m;

z=ca/(2*ma*wp);



r=0:.01:rfin;       %r=wdr/wp

r=r';



num=(2*z*r).^2+(r.^2-b^2).^2;



den1=((2*z*r).^2).*(r.^2-1+mu*r.^2).^2;

den2=(mu*r.^2*b^2-(r.^2-1).*(r.^2-b^2)).^2;



f=sqrt(num./(den1+den2));

axis([0 rfin 0 max(f)*1.5]);

plot(r,f)



title('Normalized amplitude of the primary mass')

ylabel('|Xk/Fo|')

xlabel('normalized frequency - wdr/wp')

text(.2,.85,['Primary mass frequency = ',num2str(wp),' rad/s'],'sc')

text(.2,.8,['Frequency ratio (beta) = ',num2str(b)],'sc')

text(.2,.75,['Mass ratio (mu) = ',num2str(mu)],'sc')

text(.2,.70,['Absorber damping ratio = ',num2str(z)],'sc')