  Fueled by their excellent stiffness-to-weight ratio and the availability of
mature manufacturing technologies, filament wound carbon fiber reinforced
polymers represent ideal materials for thin-walled laminate structures.
However, their strong anisotropy reduces structural resistance to wall
instabilities under shear and buckling. Increasing laminate thickness degrades
weight and structural efficiencies and the application of a dense internal core
is often uneconomical and labor-intensive. In this contribution, we introduce a
convex linear semidefinite programming formulation for truss topology
optimization to design an efficient non-uniform lattice-like internal
structure. The internal structure not only reduces the effect of wall
instabilities, mirrored in the increase of the fundamental free-vibration
eigenfrequency, but also keeps weight low, secures manufacturability using
conventional three-dimensional printers, and withstands the loads induced
during the production process. We showcase a fully-automatic procedure in
detail for the design, prototype manufacturing, and verification of a
simply-supported composite machine tool component, including validation with
roving hammer tests. The results confirm that the 3D-printed optimized internal
structure almost doubles the fundamental free-vibration eigenfrequency,
allowing to increase working frequency of the machine tool, even though the
ratio between elastic properties of the carbon composite and the ABS polymer
used for 3D printing exceeds two orders of magnitude.
