Plotting messy functions with fplot

I'm trying to plot the function v(t) below, but to no avail. My computer just gets stuck on the plot line of code. What can I do to plot this?

if true
k = 13.84*10^3;
m0 = 2.85*10^6;
vex = 34*10^6;
beta = 1.6 * 10.^-4; 
d = 10;
b = beta * d;
c = .75 * d^2;
syms t v(t)
m = -k*t;
v(t) = symfun(sqrt(c * vex) / sqrt(c) * (((1 + (k*t/m0)^(2*sqrt(c*vex)/sqrt(k))))/(1 - (k*t/m0)^(2*sqrt(c*vex)/sqrt(k)))),t)
fplot(v)

end