Many recent works have shown that organic matrices employed to produce composite materials are hydrophilic. It is thus of first importance to study the moisture diffusion process within these materials since it leads to a significant drop of the mechanical properties and to relevant internal mechanical states. Those high internal stresses may then favor the material damage leading, for instance, to crack propagations within the matrix. Moreover, the complex physic of the problem is submitted to significant uncertainties which should be taken into account when one seeks robust predictions. The project aims at linking recent and efficient numerical approaches in order to study the coupling between water diffusion and damage; the proposed techniques will be extended to the stochastic framework.
Scientific advances and innovation
Water diffusion in composites has already been widely studied by many international research teams which tend to say that its impact is harmful for the material. However, even if experimental results exist, we do not find efficient numerical methods associated to relevant models which allow predicting the behavior of the structure. This project will lead to significant advances on the development of models and numerical techniques. Besides, all proposed tools will be extended to the stochastic framework so that uncertainties on physical phenomena, geometry, and crack paths can be taken into account. Such approaches will enable to characterize in a probabilistic manner, with statistical information and/or probability laws, critical quantities of interest used in the design of MRE structures. They will also permit a better understanding of coupling between moisture diffusion and composites damage.
Expected technical and economic impact
Marine Renewable Energy structures are from now on widely made of organic matrix based composites which possess excellent mechanical properties but which may be damage by various attacks from marine environment. The aim of the project is to develop numerical tools for engineers which will allow studying the influence of water diffusion within the composites on the material damage. These tools will allow optimizing the lifespan of MRE structures and reducing the cost of the energy produced.
Key project milestones
- October 2016 - Project beginning
- October 2017 - Bibliographic report and development of deterministic coupled model
- October 2018 - Development of deterministic coupled model and extension of uncoupled models to the stochastic framework
- October 2019 - Development of stochastic coupled model, thesis defense and papers in international journals
Development of numerical tools in order to analyze the damage of composite materials employed in Marine Renewable Energy structures.
Publications and papers published
- Multiphysics modeling of the hygro-mechanical behavior of composites used in Marine Renewable Energy structures, A. Clément, A. Uguen, Q. Dézulier, S. Fréour, F. Jacquemin (GeM, Research Institute in Civil and Mechanical Engineering, CNRS UMR 6183, Nantes University, Centrale Nantes, France) – French American Innovation Day 2019 – Download the poster