Failure mechanisms of clear wood identified at wood cell level by an approach based on the extended finite element method. (August 2015)

• Record Type: Journal Article
• Authors: Lukacevic, Markus; Füssl, Josef; Lampert, Ralf
• Is Part Of: Engineering fracture mechanics. Volume 144(2015)
• Page Start: 158
• Page End: 175
• Publication Date: 2015-08
• Subjects: Wood -- Failure mechanisms -- Unit cell method -- XFEM; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2015.06.066
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: Failure processes in wood are well described with numerical simulations. Crack initiation and orientation are linked to microstructural characteristics. Failure modes at cell wall level were identified, classified and evaluated. 1600 load combinations allow the definition of a multisurface failure criterion. Crack paths through the annual year ring structure could be reproduced correctly. Abstract: Within wooden boards, initiation and global direction of cracks are governed by structural features on the microscale. Thus, and to account for the layered structure of wood, all possible failure mechanisms for two repetitive units are identified by an approach based on XFEM. The resulting failure modes of 800 numerical fracture simulations for each cell type are classified and lead to the definition of two multisurface failure criteria. Finally, these criteria are applied to tensile tests at the annual year ring scale, showing that the developed approach is able to reproduce essential failure mechanisms in wood correctly.