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Alex Trounev
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First, there is a mistake in the sign k. And secondly, for such tasks we use a special method that expands the possibilities of the shooting method. I will demonstrate the working code

A1 = 200;
A2 = 186*10^5;
A3 = 1/5000;
a = Rationalize[A2*A3^3];
H = 1; r0 = 10^-5;
f[z_, r_] := A1*(z + H) + a*(1/(Sqrt[z^2 + r^2] - 1))^3;
k = -z''[r]/(z'[r]^2 + 1)^(3/2) - z'[r]/(r Sqrt[z'[r]^2 + 1]);
sol = ParametricNDSolveValue[{k == f[z[r], r], z'[r0] == 0, 
    z[r0] == z0}, z, {r, r0, 1}, {z0}];
Plot[Evaluate[Table[sol[z0][r], {z0, -1.15, -1.05, .01}]], {r, r0, 1},
  PlotRange -> All]

fig1

Find the parameter that satisfies the boundary condition on the right border

FindRoot[sol[z0][1] == -H, {z0, -1.05}]

Out[]= {z0 -> -1.03176}
{Plot[sol[-1.03176][r], {r, r0, 1}],Plot[{sol[-1.03176][r], -Sqrt[1 - r^2]}, {r, r0, 1}]}

fig2

Alex Trounev
  • 48.8k
  • 3
  • 51
  • 115