3D simulation of damage behavior of GFRPs in the very high cycle regimeWednesday (28.09.2016) 10:30 - 10:45 Part of:
In the last decades there has been a lot of research activity in the field of modeling the fatigue behavior of fiber-reinforced plastics (FRPs). The models investigated can be mainly classified in three groups: (i) fatigue life concepts, (ii) phenomenological models and (iii) progressive damage models. Unfortunately, the consideration of a high number of load cycles is not possible with these types of models and their applicability to arbitrary structures has not been completely investigated. A recently developed fatigue damage model, (FDM) , combines the advantages of the different groups and is closest to the second type of models. This FDM is physically motivated by using an approach that relates energy dissipated under quasi-static case and the energy dissipated under cyclic loading. Fatigue phenomena such as stress redistributions and sequence effects can be analyzed with the FDM and also the degradation of stiffness and strength is layer based.
Originally, FDM was based on 2D formulation with the applicability to layer based shell elements. In the present work, FDM is further extended to the 3D case using solid elements. Moreover an extension of Puck failure criterion  to the 3D framework and also inclusion of stiffness and strength degradations in all directions have been consistently applied. The extended FDM is used for numerical simulations of the very high cycle fatigue (VHCF) behavior for specific reference cases. Recently, experimental investigations for the VHCF behavior of GFRP specimens have been carried out using a four-point bending setup . Results obtained from the original FDM (2D) and the present work (3D) are compared and finally validated with the results obtained from the experiment.
 Heiko Krüger and Raimund Rolfes: A physically based fatigue damage model for fibre-reinforced plastics under plane loading. In International Journal of Fatigue, Volume 70, January 2015, Pages 241–251.
 A. Puck: Festigkeitsanalyse von Faser-Matrix-Laminaten – Modelle für die Praxis. Carl Hanser Verlag (ISBN 3446181946), Munich, 1996.
 T.J. Adam and P. Horst: Experimental investigation of the very high cycle fatigue of GFRP [90/0]s cross-ply specimens subjected to high-frequency four-point bending. In Composites Science and Technology, Volume 101, 12 September 2014, Pages 62–70.