Strength and fracture analysis of laminated wood-based structural elements

Cross laminated timber (CLT) from softwoods has been an important enabler of the increased use of bio-based structural materials.

However, a general disadvantage of CLT is that the consumption of raw material is high, often unnecessarily high, as the same type of element layup is used for different structural parts, although the performance requirements for stiffness and load-bearing capacity can differ greatly.

There should be great potential for improved material efficiency through the development of innovative concepts for the geometric design.

Also a wider raw material base, including hardwood species, should enable improved mechanical performance.To create safe and material-efficient buildings, it is of utmost importance for engineers to have access to accurate and rationally based design methods. The geometric form of the considered elements gives complex stress states and many potential failure modes.

Shear, both along and perpendicular to the grain, and transverse tensile stress, is particularly challenging and further research is needed.The project concerns development of calculation models using FEM and experimental tests.

The aim is to provide increased knowledge of the mechanical behaviour of innovative wood-based structural elements and development of improved tools for calculating stiffness and load-bearing capacity.

The project examines the possibilities for designing material-efficient and high-performance elements produced from softwood and hardwood lamellas.