Warning: Reached the limit on the maximum number of intervals in use. Approximate bound on error is 2.4e+02. The integral may not exist, or it may be difficult to approximate numerically to the requested accuracy.

Hi all, I'm try to solve the integral in the code and I have the error. Any suggestions? The function seems to not have singularities.

Roi=916; 
Row=1024; 


r=50; 
d=50; 


H0=50; 

va=9.46 
vi=30.99 

b=(H0-vi*vi/(2*9.806))*2
a=(vi/va-1)*(3/2*Roi/Row*b)

N=1000
t=linspace(0,30,N)
for i=1:length(t)
E1=@(x)besselj(0,r/d.*x).*sqrt(x.*tanh(x)).*x.*sin(sqrt(9.81*t(i)^2/d.*x.*tanh(x))).*(sin(a/d.*x)-a./d.*x.*cos(a/d.*x))./(a/d.*x).^3
E(i)= integral(E1,0,inf) 
end


E2=-2*(a^3)/(d^3)*sqrt(2*H0/d-a/d*b/a)/(1+2/3*Row/Roi*a/b)*E*d;
max(E2)

plot(t,E2)

Answer 1

[Torsten]

E1=@(x)besselj(0,r/d.*x).*sqrt(x.*tanh(x)).*x.*sin(sqrt(9.81*t(i)^2/d.*x.*tanh(x))).*(sin(a/d.*x)-a./d.*x.*cos(a/d.*x))./(a/d.*x).^3

At x=0, you divide by 0 here.

[Tommaso Attili]

Thanks for that. But this doesn't solve the problem.