  We study the stability of Riemann solutions to pressureless Euler equations
with Coulomb-like friction under the nonlinear approximation of flux functions
with one parameter. The approximated system can be seen as the generalized
Chaplygin pressure Aw-Rascle model with Coulomb-like friction, which is also
equivalent to the nonsymmetric system of Keyfitz-Kranzer type with generalized
Chaplygin pressure and Coulomb-like friction. Compared with the original
system, The approximated system is strictly hyperbolic, which has one
eigenvalue genuinely nonlinear and the other linearly degenerate. Hence, the
structure of its Riemann solutions is much different from the ones of the
original system. However, it is proven that the Riemann solutions for the
approximated system converge to the corresponding ones to the original system
as the perturbation parameter tends to zero, which shows that the Riemann
solutions to nonhomogeneous pressureless Euler equations is stable under such
kind of flux approximation. The result in this paper generalizes the stability
of Riemann solutions with respect to flux perturbation from the well-known
homogeneous case to the nonhomogeneous case.
