Micromechanical behavior of UHPC under cyclic bending‐tensile loading in consideration of the influence of the concrete edge zone. Issue 1 (17th December 2018)

• Record Type: Journal Article
• Authors: Harenberg, Stefan; Caggiano, Antonio; Koenig, Andreas; Said, Diego; Gilka‐Bötzow, Albrecht; Schultz‐Cornelius, Milan; Yang, Sha; Pahn, Matthias; Dehn, Frank; Koenders, Eddie
• Other Names: Müller G. guestEditor.; Ulbrich M. guestEditor.
• Is Part Of: Proceedings in applied mathematics and mechanics. Volume 18:Issue 1(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-12-17
• Subjects: Applied mathematics -- Periodicals; Engineering mathematics -- Periodicals; Mathematical physics -- Periodicals; 519
• DOI: 10.1002/pamm.201800363
• Languages: English
• ISSNs: 1617-7061

Abstract

Abstract: This paper provides preliminary results of a research study on the fatigue behavior of Ultra‐High‐Performance Concrete (UHPC). Results of an experimental campaign, performed at the Department of Concrete Structures and Structural Engineering of the TU‐Kaiserslautern, are firstly proposed. The heterogeneous meso‐structure and material degradation of UHPC are studied through cyclic bending‐tensile tests. A test set‐up is specially developed at the TU‐Kaiserslautern to perform such activities. Particularly, different upper stress cycles (namely, cycle reversals) characterized by different force/stress amplitudes are considered and analyzed. The influence of the edge zone on the stress cycles is tested on notched and normal specimens while the results are used for composing a so‐called "Wöhler curve" of the materials' fatigue behavior. Damage progress during loading is monitored by means of a Digital Image Correlation system (DIC) and the results are used for improving the measurement accuracy. Based on these results, macroscopic and mesoscale simulations are performed at the TU‐Darmstadt's Institute of Construction and Building Materials. A meso‐mechanical approach for the numerical analysis of UHPC specimens subjected to low‐ and high‐cycle fatigue actions will be presented. The possibilities of modeling the material fracture response induced by fatigue is taken into account by means of a systematic use of zero‐thickness interface elements equipped with a fracture‐based model and combined with a continuous damage constitutive law. A plastic‐damage based model for concrete subjected to cyclic loading is developed combining the concept of fracture‐energy theories with a stiffness degradation, representing the key phenomenon occurring in concrete under cyclic responses. The experimental and numerical activities proposed in this paper stem out from the DFG Priority Program 2020 Project "Cyclic Damage Processes in High‐Performance Concretes in the Experimental Virtual Lab".