The Fused Deposition Modeling (FDM) is one of the most commonly used additive manufacturing processes. This process is characterized by the deposition of a fused, thermoplastic filament. The mechanical properties of thin-walled plastic components are limited. One approach to improve the strength or stiffness of these components is to reinforce the thin-walled areas with an individually adapted FDM-structure. Depending on the form of the reinforcement structure, the resulting hybrid structure should show a higher strength or stiffness. The objective of the project is to determine constructive design and process guidelines for FDM-structures. The FDM-structure shall be used as a partial reinforcement for lightweight components and be adapted to the respective load conditions. Because of the light weight application, the FDM-structure should also be of the lowest possible weight. The optimization of the FDM-parts for different load cases is realized by adapting the design parameters. These parameters influence the layer generation and therefore also the inner structure of the FDM-parts. Besides the optimization of the inner structure the form of the FDM-structures is varied, too. The form adjustment of the FDM-parts is based on a FEM analysis and a following topology optimization to exploit the maximum lightweight construction potential. The anisotropic properties of the FDM-parts must be considered during the topology optimization. In preliminary studies the manufacturing restrictions of the FDM-process are detected. The specimens are manufactured based on the Design of Experiments. To determine the static strength properties different tests (tensile, pressure, bending, torsion and impact test) are conducted. The investigations show that the filling strategy affects the mechanical properties. As a result of the investigations, design and process guidelines for the FDM-structures are established according to the load conditions.