This paper aims to define the influencing design criteria for compliant folding mechanisms with pneumatically actuated hinges consisting of fiber-reinforced plastic (FRP). Through simulation and physical testing, the influence of stiffness, hinge width as well as variation of the stiffness, in the flaps without changing the stiffness in the hinge zone, was evaluated. Within a finite element model software, a workflow was developed for simulations, in order to infer mathematical models for the prediction of mechanical properties and the deformation behavior as a function of the aforementioned parameters. In conclusion, the bending angle increases with decreasing material stiffness and with increasing hinge width, while it is not affected by the flap stiffness itself. The defined workflow builds a basis for the development of a predictive model for the deformation behavior of FRPs.

Polymer concrete has proved to be advantageous in machine building for many years thanks to its excellent damping properties. Until now, its use was limited to machine beds due to its comparatively low tensile strength. Its use in moving structural components has not been possible until now. Recent research results have shown that this challenge can be met by integrating prestressed carbon fibers. Until now, the production of samples out of prestressed fiber-reinforced polymer concrete has been carried out according to fixed specifications. It is not yet clear whether these specifications are suitable to fully exploit the potential of the material. Samples manufactured to these specifications show at least a large scatter in bending stiffness. Within the scope of this paper, the existing manufacturing process is validated by the variation of process steps. Specifically, this involved the use of a shaker, variation of the dwell time in the mold, variation of the resin content, and the procedure for impregnating the fibers. The characterization of the samples showed that the scatter could only be reduced by increasing the dwell time. However, this leads to a decrease in bending stiffness and, thus, is not suitable for further improvement of the novel material.

Polymer concrete is increasingly used in high-precision machine tools due to its excellent damping properties, thermal stability, and reduced environmental impact. However, its low tensile strength and stiffness limit its use in structural or dynamically loaded components. This study examines the mechanical enhancement of polymer concrete through the integration of prestressed continuous carbon fiber reinforcements. Specimens with embedded carbon fiber rovings prestressed up to 470 MPa were fabricated and tested under three-point bending and uniaxial compression loading. Bending strength increased by up to 35 % and bending stiffness by 16 %, with significant gains occurring beyond a prestress level of 70 – 110 MPa. CT imaging confirmed that prestressing delayed crack initiation and limited propagation. Under compressive loading parallel to the fiber direction, strength increased by up to 8 %, though the effect diminished at higher prestress levels. A reduction in compressive strength was observed for transverse loading, attributed to matrix discontinuities and stress redistribution. The results demonstrate that prestressed fiber integration significantly improves the structural performance of polymer concrete, offering enhanced load capacity and failure resistance. These findings lay the foundation for broader application of polymer concrete in load-bearing components and support the development of hybrid systems combining mechanical efficiency with design flexibility.