Azzera filtri
Azzera filtri

Solution of spring mass system with cubic stiffness

4 visualizzazioni (ultimi 30 giorni)
I have below equation to solve with a given time series of gaussian white noise as f(t). Here is my code but it gives dimension error between result and the initial conditions vector. Is there any idea to fix it? Here is the error message:
Error using odearguments (line 92)
@(T,Y)SPRING(T,Y,M,C,K,K2,K3,F) returns a vector of length 10001, but the length of initial conditions vector is 2. The vector returned by @(T,Y)SPRING(T,Y,M,C,K,K2,K3,F) and the initial conditions vector must have the same number of elements.
Error in ode45 (line 115)
odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);*
my''+cy'+ky+k2*y^2+k3*y^3=f(t)
m=1; c=1; k=10; k2=20; k3=20;
f=randn(10000,1);
tspan=[0 10000];
y0=[0;1];
function dydt=spring(t,y,m,c,k,k2,k3,f)
dydt=[y(2); (f-c*y(2)-k*y(1)-k2*y(1)^2-k3*y(1)^3)/m];
end
[t,y]=ode45(@(t,y) spring(t,y,m,c,k,k2,k3,f), tspan, y0);

Risposta accettata

Torsten
Torsten il 11 Ott 2018
function main
m=1; c=1; k=10; k2=20; k3=20;
tspan=[0 10000];
y0=[0;1];
f=randn(10000,1);
tf = linspace(tspan(1),tspan(end),10000); % time vector at which the f-values occured
[t,y]=ode45(@(t,y) spring(t,y,m,c,k,k2,k3,tf,f), tspan, y0)
end
function dydt=spring(t,y,m,c,k,k2,k3,tf,f)
f_actual = interp1(tf,f,t);
dydt=[y(2); (f_actual-c*y(2)-k*y(1)-k2*y(1)^2-k3*y(1)^3)/m];
end

Più risposte (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by