Naturally grown timber elements as the basis for load-bearing structures


Structural analysis and growth simulation

© Chair of Structures and Structural Design  

Project description

The increasing sensitivity of our society to the impact of human interventions in nature and the environment is promoting the research of natural materials and leading to an increased use of wood in construction. Wood constructions, which traditionally are based on prefabricated semi-finished products, are built with geometrically simple and adaptable basic shapes. Prefabrication techniques enable homogenization, achieving universal mechanical properties (glulam). However, the production of wooden building elements in the form of boards, rods, and beams is associated with considerable logistical and productive effort, in which only trunk wood is used, resulting in a large amount of waste. Traditional timber construction and structural systems with predominantly linear elements are therefore optimized for universal use and for the construction of components with orthogonal geometry. Through the development of alternative timber construction systems, such as the 'off-knot construction', naturally grown timber elements can also be used with minor adaptations. For this purpose, advanced digital methods such as image-based modeling and morphological analysis and classification are used to generate the geometry of new structures from individual naturally grown timber building elements and their associated cross-sections. Advanced nonlinear simulation techniques and numerical modeling, such as isogeometric analysis, consider a polar arrangement of layers, different densities along the radius with variable strength properties, representing the configuration of a fibrous material with the typical anisotropic behavior of wood. Based on this analytical tool, a synthetic approach is developed to simulate the growth of a tree, which is influenced by simple gravitational tropism or by forces in general. For this purpose, the material properties in the living and denatured (dry) state of the wood, as well as the biological changes that influence the mechanical properties, must be derived. The most important biological influencing factors, such as the development of the fiber tissue and the density, must be identified and transferred to simulation parameters. The project aims for an innovative approach to the systematic use of naturally grown timber as well as a deeper understanding of the growth of trees.

DFG Project Nr: *512769030*


TRAKO's research team, together with LBB and IBG-2 , is exploring types of wood that are geometrically underutilized industrially. This work is intended to establish a basis for the design of structures, along with experiments with different construction and joining methods. To support their research, the team is developing simulation tools that model the growth of different types of wood, which is an essential part of developing a mechanistic study of tree growth. This work includes the development of NURBS models supported by image-based modeling methods, 3D scans, and Tomographic reconstruction. With the support of Wald und Holz NRW local hardwoods species are being studied.


Teaching courses

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