  The Numerical Assembly Technique is extended to investigate arbitrary planar
frame structures with the focus on the computation of natural frequencies. This
allows us to obtain highly accurate results without resorting to spatial
discretization. To this end, we systematically introduce a frame structure as a
set of nodes, beams, bearings, springs, and external loads and formulate the
corresponding boundary and interface conditions. As the underlying homogeneous
solution of the governing equations, we use a novel approach recently presented
in the literature. This greatly improves the numerical stability and allows the
stable computation of very high natural frequencies accurately. We show this
numerically at two frame structures by investigation of the condition number of
the system matrix and also by the use of variable precision arithmetic.
