Computational mechanical modelling of wood—from microstructural characteristics over wood-based products to advanced timber structures

Abstract

Wood as structural bearing material is often encountered with skepticism and, therefore, it is not used as extensively as its very good material properties would suggest. Beside building physics and construction reasons, the main cause of this skepticism is its quite complex material behavior, which is the reason that design concepts for wood have so far not achieved a desirable prediction accuracy. Thus, for the prediction of effective mechanical properties of wood, advanced computational tools are required, which are able to predict as well as consider multidimensional strength information at different scales of observation. Within this chapter, three computational methods are presented: an extended finite element approach able to describe strong strain-softening and, thus, reproduce brittle failure modes accurately; a numerical limit analysis approach, exclusively describing ductile failure; and an elastic limit approach based on continuum micromechanics. Based on illustrative results, the performance of these methods is shown and discussed. Furthermore, a finite-element-based design procedure for an elastically-deformed wooden structure is outlined, showing how advanced mechanical information of the base material could be exploited within digital design of complex timber structures in future. Finally, geometric design concepts applicable within digital wood design are discussed, giving insights into possible future developments.