Speaker
Description
Concrete and cement-based materials are known to describe a brittle failure. Thus, fiber reinforcement is used to enhance the post-cracking properties of the material. In this regard, the polymer fibers arise as an environmentally friendlier alternative to steel fibers. However, the effect of their characteristic viscoelastic behavior on the performance of fiber-reinforced concrete requires further research. Therefore, the influence of viscoelastic behavior of the polymer fibers on the failure of high-performance concrete (HPC) is investigated. The three-point bending boundary value problem is used with two loading stages: short-timed monotonically loading is followed by constant load. The test is repeated at different loads to reach the non-linear viscoelasticity of the fibers. For that purpose, the developed phenomenological model for fiber-reinforced high-performance concrete, see [1], combined with the non-linear viscoelastic Schapery model from [2] see also [3], is implemented. The failure behaviors of the HPC in tension and compression are governed by step-wise linearly approximated degradation functions, see [4]. The orientation distribution functions (ODF) containing different distributions and orientations are implemented, as proposed in [5]. Finally, the performance of the numerical model is discussed using Load-CMOD (crack mouth opening displacement) curves.
References
[1] M. Pise, D. Brands, J. Schröder. Development and calibration of a Phenomenological Material Model for Steel-Fiber-Reinforced-High-Performance Concrete Based on Unit Cell Calculations. Materials, 17(10), 2247, 2024.
[2] R.A. Schapery. On the characterization of nonlinear viscoelastic materials. Polymer Engineering \& Science, 9, 295-310, 1969.
[3] M.A. Margalho de Barros, Sanjay Govindjee, J. Schröder. A note on the nonlinear viscoelastic Schapery model applied to PMMA and asphalt. Proceedings in Applied Mathematics and Mechanics, 24, e202400214, 2024.
[4] J. Schröder, M. Pise, D. Brands, G. Gebuhr, S. Anders. Phase-field modeling of fracture in high performance during low-cycle fatigue: Numerical calibration and experimental validation. Computer Methods in Applied Mechanics and Engineering, 398, 115181, 2022.
[5] G. Gebuhr, M. Pise, S. Anders, D. Brands, J. Schröder. Damage Evolution of Steel Fibre-Reinforced High-Performance Concrete in Low-Cycle Flexural Fatigue: Numerical Modeling and Experimental Validation. Materials, 15(3), 1179, 2022.
