Mikromekanik i trämaterial
Tidsperiod: 2017-01-01 till 2020-12-31
Projektledare: Kristofer Gamstedt
Budget: 3 400 000 SEK
In nature, one can find many strong tissues that show a similarity in the hierarchical helical structure, e.g. wood, bone and muscles. Wood is frequently used as a load-carrying structural material. Compared with other structural materials, wood is sensitive to moisture. What makes wood so strong, stiff, damage tolerant and resistant to fracture is not yet fully understood. Perhaps the responsible features could be used in design of engineered composite materials, with improved mechanical performance? With the increasing access to X-ray computed tomography and efficient numerical simulations, it is becoming feasible to study in detail the mechanisms of deformation, damage accumulation and failure in wood. Simulations can be made to investigate the influence of the microstructure on the moisture-induced swelling, as well as load-induced deformation and failure of wood. The first step is to experimentally investigate the deformation of single wood cells on mechanical or hygral loading. From these experiments, cell wall properties can be identified in a more direct way than previously. Comparisons will be made using other miniaturized mechanical testing techniques. Then experiments and simulations will be made on wood tissue samples, to investigate the effects of neighbouring cells, as is the case in native wood. The observed deformation and failure mechanisms will provide insight of how a damage-tolerant material could be designed.