Svenja Höper

Svenja Höper, M.Sc.

Beethovenstraße 51

38106 Braunschweig

Telephone: 0531/391-3678

Research project:

Damage Processes in Ultra-High Performance Fibre-Reinforced Concrete Subjected to Cyclic Tensile Loading - Numerical Investigations

This research project is part of the Priority Programme 2020 "Cyclic Deterioration of High-Performance Concrete in an Experimental-Virtual Lab" and is focused on understanding, describing and modelling the degradation behaviour of ultra-high performance fibre-reinforced concrete (UHPFRC) subjected to cyclic tensile loading. Based on experimental investigations at iBMB, Division of Concrete Construction, TU Braunschweig, the stress-deformation behaviour of UHPFRC is modelled consistently on the meso-scale with special regard to damage mechanisms and their evolution.

Due to possible applications of the composite material UHPFRC, macroscopic modelling has been developed almost entirely with particular focus on designing components until now. Within this research project, however, micro-structure related modelling with emphasis on the detailed description of the mechanisms behind attempts to provide additional information concerning the design of fibres and the composite material especially due to fatigue loading.

Available models describing the material behaviour of concrete and steel according to continuum damage mechanics have to be extended towards the material characteristics and the fatigue behaviour of the high-strength components of UHPFRC. Simultaneously, the available bond models developed for ribbed steel bars are revised and amplified for the application within the context of microfibres subjected to cyclic pull-out tests.

The verification of the new bond model together with the components' material models is conducted in three-dimensional finite element analyses. The numerical simulation of fibre pull-out tests is calibrated and validated according to the experimental results from single and multiple fibre pull-out tests carried out at iBMB, Division of Concrete Construction.

Publications within the framework of the RTG:

Publications in peer-reviewed scientific journals:

J.-P. Lanwer, V. Oettel, M. Empelmann, S. Höper, U. Kowalsky and D. Dinkler. Bond behavior of micro steel fibers embedded in ultra-high performance concrete subjected to monotonic and cyclic loading. Structural Concrete (Early View), S. 1-11, 2019.

Conference contribution with publication in conference proceedings:

S. Höper, U. Kowalsky and D. Dinkler. Micro‐structure related modelling of ultra‐high‐performance fibre reinforced concrete (UHPFRC) subjected to cyclic tensile loading. Proceedings of Applied Mathematics and Mechanics 18 (1), S. 1-4, 2018.[ DOI ]

S. Höper, U. Kowalsky and D. Dinkler. Mikrophysikalisch begründete Modellierung der Verbundwirkung in faserbewehrtem Ultrahochleistungsbeton (UHPFRC) unter zyklischer Zugbeanspruchung. In: Jens Schneider und Nihat Kiziltoprak (Hg.): Forschungskolloquium 2018 Grasellenbach. Baustatik-Baupraxis e.V. Wiesbaden: Springer Fachmedien Wiesbaden, S. 35-36, 2018.

S. Höper, U. Kowalsky, D. Dinkler, J.-P. Lanwer, V. Oettel and M. Empelmann. Experimental and numerical investigations of UHPFRC under cyclic tensile loading. Proceedings of the 7th International Conference on Structural Engineering, Mechanics and Computation (accepted). 2019.

J.-P. Lanwer, V. Oettel, M. Empelmann, S. Höper, U. Kowalsky and D. Dinkler. Degradation processes of UHPFRC under cyclic tensile loading. In: Derkowski, W. et al. (Ed.): Proceedings of the 16th fib Symposium, S. 1912-1919. 2019.

Additional literature:

S. Heinrich, U. Kowalsky and D. Dinkler. Evolution of nonlocal damage in mild steel under cyclic straining. Proceedings of the12th International Conference on Computational Plasticity (COMPLAS XII), 2013.

F. Cramer. Mehrfeld-Modell für chemisch-physikalische Alterungsprozesse von Beton. Dissertation, TU Braunschweig, 2016.

T. Stein, U. Kowalsky and D. Dinkler. Numerical analysis of reinforced concrete structures with particular focus on bond behaviour. Proceedings in Applied Mathematics and Medicine (PAMM), 2016.