  Hybrid numerical-experimental testing is a standard approach for complex
dynamical structures that are, on the one hand, not easy to model due to
complexity and parameter uncertainty and, on the other hand, too expensive for
full-scale experiments. The main idea is to subdivide the structure in a part
that can be accurately simulated with numerical methods and an experimental
component. The numerical simulation and the experiment are coupled in real-time
by a so-called transfer system, which induces a time-delay into the system. In
this paper, we study the solvability of the resulting hybrid
numerical-experimental system, which is typically described by a set of
nonlinear delay differential-algebraic equations, and extend existing results
from the literature to this case.
