Abstract
The simulation of the fatigue damage of laminated composites under multi-axial and variable amplitude loadings has to deal with several new challenges and several methods of damage modelling. In this paper we present how to account for the complex loading by using the damage hysteresis operator approach for fatigue. It is applied to a fatigue model for intra-laminar damage based on stiffness degradation laws from Van Paepegem and has been extended to deal with unidirectional carbon fibres. The parameter identification method is presented here and parameter sensitivities are discussed. The initial static damage of the material is accounted for by using the Ladeveze damage model and the permanent shear strain accumulation based on Van Paepegem’s formulation. This approach has been implemented into commercial software. The intra-laminar fatigue damage model combines efficient methods with a low number of tests to identify the parameters of the stiffness degradation law, this overall procedure for fatigue life prediction is demonstrated to be cost efficient at industrial level.
Highlights
The increase of lightweight material in transportation industries is today facing greater scrutiny on fatigue life prediction of composite structures based on realistic load situations
The challenge is related to the variability of those conditions: non proportional and variable amplitude loading leading to multiaxial local stress states and long duration fatigue loading
The study concluded that out of the four modelling methodology fatigue life (SN curve based), residual strength, residual stiffnessmechanics model the residual stiffness models are most suitable for mechanical performance using experimental data and can be combined with a residual strength approach
Summary
The increase of lightweight material in transportation industries is today facing greater scrutiny on fatigue life prediction of composite structures based on realistic load situations. Challenge is related to the variability of those conditions: non proportional and variable amplitude loading leading to multiaxial local stress states and long duration fatigue loading This is why Siemens PLM software [2] has developed an innovative composite fatigue CAE methodology (patent pending) keeping track of the material degradation under such conditions. The presented methodology is based on residual stiffness fatigue laws combined with an efficient damage operator approach to calculate the progressive damage and residual stiffness. This approach is able to perform fatigue simulations for variable amplitude loads and allows ply-stacking optimization without additional testing or material characterizations.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
