A higher-order solid finite element for multi-layered timber structures

ABSTRACT The development of high-performance and computationally efficient numerical models for multi-layered timber structures remains a significant challenge due to the complex behaviour of timber and the assembly of the structure. The objective of this paper is to propose a new methodology based on a higher-order solid finite element for modelling multi-layered timber beams assembled with wood dowels. The proposed 32-node solid element is implemented via a user subroutine in the Abaqus software and tested through two cases. First, an academic single orthotropic lamella with different length-to-thickness ratios is treated. Secondly, a large scale multi-layered timber beam assembled with compressed wood dowels has been dealt. It is noteworthy to mention that it is the first time this type of higher-order element has been applied to an industrial application. Through a comprehensive numerical study of the multi-layered timber beam, it is shown that the displacement fields within the lamellae and dowels exhibit cubic-order displacement fields. The performance of the 32-node element which contains these cubic terms is evaluated and compared to conventional 20-node elements. Results demonstrate that the 32-node element achieves improved accuracy with coarse meshes, resulting in significantly reduced computational cost. This approach provides a new framework for modelling complex industrial structures and promotes more sustainable numerical modelling practices.