Fracture toughness of Khaya ivorensis and Magnolia obovata for mobility applications

This work focuses on the study of the fracture toughness of two wood species. It investigates the opportunity of using alternative wood species to Magnolia obovata, a Japanese species, to design satellites based on wooden structures. The use of wooden structures would enable us to move towards carbon neutrality in the long term. Khaya ivorensis, a tropical species of African origin, is explored in this context. More specifically, a comparison of the fracture processes between Khaya ivorensis and Magnolia obovata is carried out to assess their durability against the loads they may encounter in extreme applications. Tests are conducted in crack opening and mixed modes configurations, using Localized Spectrum Analysis (LSA), an innovative approach for measuring displacement and strain fields. The energy release rates are evaluated using the compliance method under imposed displacement. The decoupling of the fracture modes allowed for determining the contributions of Mode I and Mode II in mixed mode. Additionally, Scanning Electron Microscope (SEM) observations were performed to examine the impact of wood anatomy on fracture surfaces and fracture parameters. Khaya ivorensis demonstrated better fracture performance, revealing results consistent with its density and ribbon-like structure.