Abstract
Fracture properties belong to one of the most important properties of wood due to its safety consequences that come out of the wood cellular structure and natural phenomena occurring in wood such as cracks. Cracks in wood may substantially decrease mechanical performance of wooden beams because they create stress contraction spots and, therefore, they should be studied with appropriate attention. To test fracture properties of wood, one can employ many techniques and tests. Specific testing procedures have certain requirements on specimens with respect to wood nature – grain angle, moisture, species and others. The general goal of this work is to analyze so called end-notched flexure test in three-point bending (ENF-3PB) scheme to provide fracture behavior of wood using such a test. The work consisted of utilizing 3D finite element analysis (FEA) to analyze sensitivity of testing procedure to various variables introduced to a specimen such as span-to-height ratio, friction coefficient and length of initial crack. The analyses considered wood as orthotropic material including both elastic and plastic regions of deformation using Hill’s plasticity. The crack path is modeled using cohesive zone models, contact between specimen and loading grips and supports was modeled using contact algorithms. Results show that ENF-3PB test is very sensitive to setup and in case of cumulative effect of studied phenomena, the measurement error might not be negligible.
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Experimental and numerical assessment of the bearing capacity of notches in timber beams at arbitrary locations using LEFM [Grant Agreement #21-29389S].
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Sebera, V., Kunecký, J. (2024). Numerical Study of Three-Point Bending Fracture Tests for Examination of Wood in Mode II. In: Endo, Y., Hanazato, T. (eds) Structural Analysis of Historical Constructions. SAHC 2023. RILEM Bookseries, vol 46. Springer, Cham. https://doi.org/10.1007/978-3-031-39450-8_51
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DOI: https://doi.org/10.1007/978-3-031-39450-8_51
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