The fracture mechanism of softwood via hierarchical modelling analysis

• Published in: Journal of wood science Vol. 65; no. 1; pp. 1 - 11
• Main Authors: Wang, Dong, Lin, Lanying, Fu, Feng, Fan, Mizi
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.12.2019; Springer Nature B.V; SpringerOpen
• Subjects: Biomedical and Life Sciences; Characterization and Evaluation of Materials; Computer simulation; Fracture mechanics; Hierarchical model; Initial fracture; Life Sciences; Materials Science; Review Article; Shear stress; Softwood; Stress concentration; Tensile stress; Wood Science & Technology; Stress concentration; Hierarchical model; Softwood; Initial fracture
• ISSN: 1435-0211; 1611-4663
• DOI: 10.1186/s10086-019-1837-x

A hierarchical model of softwood was developed to effectively analyze stress concentration and predict initial fracture of the wood cell wall under different loading scenarios. The results indicated that the simulated stress concentration regions of the tracheid wall approximately matched the experimental initial fracture locations. The stress concentration and initial fracture of the tracheid wall under longitudinal tensile stress occurred in the S 2 layer. In the cases of pure longitudinal–radial (LR) or longitudinal–tangential (LT) in-plane shear loading, the highest stresses are observed in the S 1 /S 2 interface and the S 3 layer, but the initial fractures of the tracheids of the neutral layer under the LR or LT shear stress only occurred in the S 1 /S 2 interface. Furthermore, the tracheids of the tensile parts outermost of bending specimen were subjected to the longitudinal tension and shear coupling stresses that led to the two kinds of cracks occurring, including trumpet-shaped cracks in the S 2 layer, and S 1 /S 2 interface debonding.