Investigation on multiaxial strength reduction for multi-directional laminates under variable amplitude loading

39th Risø International Symposium on Materials Science 'Fatigue of Composite Materials: Microstructure, Mechanics and Methods'

Möller, M.^1 ; Blaurock, J.^1 ; Ziegmann, G.^2 ; Esderts, A.^3

TH Köln, Institute for Automotive Engineering, Betzdorfer Straße 2, Cologne

50679, Germany^1

TU Clausthal, Institute of Polymer Materials and Plastics Engineering, Agricolastr. 6, Clausthal-Zellerfeld

38678, Germany^2

TU Clausthal, Institute for Plant Engineering and Fatigue Analysis, Leibnizstr. 32, Clausthal-Zellerfeld

38678, Germany^3

关键词: Classical laminate theory;    Fatigue life estimation;    Fatigue of composites;    Multi-directional laminates;    Multiaxial strength;    Multiaxial stress state;    Variable amplitude load;    Variable amplitude loading;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/388/1/012015/pdf
DOI  :  10.1088/1757-899X/388/1/012015

来源: IOP

【 摘 要 】

Due to their excellent ratio of high strength and stiffness to low density, the use of composite materials in lightweight solutions is growing in widely varying industry sectors. Most of the lightweight structures are loaded cyclically and therefore there is the need for optimized computation models concerning the fatigue of composite materials. The present study mainly focuses on the fatigue life estimation of continuous fibre reinforced plastics under variable amplitude loads. The approach is based on iterative ply-wise calculation of multiaxial stress states using classical laminate theory and a subsequent analysis of the material effort with the use of the failure criteria by Puck. A number of suitable linear and nonlinear residual strength models are examined for an in-depth approach on the multiaxial strength reduction at the ply-level. The aim of this study is to calculate fatigue life of multi-directional laminates with input data from uni-directional plies only. The model is finally validated for a multi-directional laminate under variable amplitude loads with arbitrary pulsating and alternating stress ratios using experimental data from the well documented composite fatigue data base OptiDAT.