Research Projects of the first cohort
In order to achieve highly ductile, extremely energy-absorbing material and structural behavior under impact stress, new material concepts and reinforcement types have to be developed. The basis of this development is strain-hardening short fiber reinforced concrete (SHCC) with a tensile elongation of more than 5% under quasi-static load as well as flat and spatial reinforcement structures from continuous fiber bundles (A1/I Development and evaluation of 3D reinforcing structures for structural strengthening against impact loading). The combination of textile structures and short fibers (hybrid fiber reinforcements) is also very promising (A3/I Development and characterization of hybrid-fiber reinforced composites for structural strengthening against impact loading). A goal-oriented design of the new composites’ properties under high strain rates is to be achieved by fundamental, multiscale, experimental and theoretical-numerical interdisciplinary investigations. The characterization of the new materials with predominantly anisotropic material behavior requires the design and implementation of new highly dynamic test and measurement techniques (A4/I Experimental characterization of the mechanical behavior of anisotropic and strain-hardening composites under impact loading, C1/I 3D measurement techniques of fracture processes). The experimental work will proceed together with the development of new numerical approaches such as the multiscale simulation of the anisotropic damping behavior of fiber reinforced concrete under impact in the fine mesoscale (B1/I Multi-scale simulation of the anisotropic damping properties of fiber-reinforced concrete under impact loading). The expansion of the developed numerical method by a bionic remodeling approach (B1/I Multi-scale simulation of the anisotropic damping properties of fiber-reinforced concrete under impact loading) is intended to allow the calculation of an optimal reinforcement orientation. The interphase design also plays an important role for the fiber-matrix composite (A2/I Strain-rate dependent composite behavior of fiber reinforcement in mineral-based matrices) which is favorable in terms of the fracture behavior. Furthermore, significant improvements are expected from higher heterogeneity or an engineered composition of the matrix (A3/I Development and characterization of hybrid-fiber reinforced composites for structural strengthening against impact loading). These conceptual-experimental developments are to be improved by the establishment of a physically motivated damage model for the description of the fiber pullout (B3/I Modeling textile reinforced components).
In the development of reinforcement solutions using new composites, variants for their application are considered both on the impact-facing side (A5/I Strengthening of plane RC elements against impact on the impact-far side) and on the impact-opposite side (A6/I Strengthening of plane RC elements against impact on the impacted side). Through this process natural principles of impact absorption with regard to their adaptability for reinforcement layers for structural components should be examined (A6/I Strengthening of plane RC elements against impact on the impacted side). The new impact-resistant composites and reinforcing systems should be developed and evaluated not only from an engineering but also from an economic and ecological point of view (C2/I Analysis and assessment of the sustainability and resilience of reinforcement methods with new composites).