Statistical modelling of the fatigue bending strength of Norway spruce wood

Klemenc, Jernej (author), Fajdiga, Gorazd (author)

When wood is used as a structural material, the fact that it is a highly inhomogeneous material, which significantly affects its static and fatigue properties, presents a major challenge to engineers. In this paper, a novel approach to modelling the fatigue-life properties of wood is presented. In the model, the common inverse-power-law relationship between the structural amplitude loads and the corresponding number of load cycles to failure is augmented with the influence of the wood’s mass density, the loading direction and the processing lot. The model is based on the two-parametric conditional Weibull’s probability density function with a constant shape parameter and a scale parameter that is a function of the previously mentioned parameters. The proposed approach was validated using the example of experimental static and fatigue-strength data from spruce beams. It turned out that the newly presented model is capable of adequately replicating the spruce’s S-N curves with a scatter, despite the relatively scarce amount of experimental data, which came from different production lots that were loaded in different directions and had a significant variation in density. Based on the experimental data, the statistical model predicts that the lower density wood has better fatigue strength.

• Language: English
• Keywords: spruce wood, wood density, static material characteristics, fatigue strength, Weibull’s probability density function, augmented inverse power law
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering; BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: 15 str.
• Numbering: Vol. 15, iss. 2, art. 536
• PID: 20.500.12556/RUL-134398
• UDC: 630*8
• ISSN on article: 1996-1944
• DOI: 10.3390/ma15020536
• COBISS.SI-ID: 93092867
• Publication date in RUL: 13.01.2022

Record is a part of a journal

• Title: Materials
• Shortened title: Materials
• Publisher: MDPI
• ISSN: 1996-1944
• COBISS.SI-ID: 33588485

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 11.01.2022

Secondary language

• Language: Slovenian
• Keywords: smrekovina, gostota lesa, statične lastnosti materiala, dinamična trdnost, Weibullova gostota porazdelitve verjetnosti, razširjeni inverzni potenčni zakon

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0182
• Name: Razvojna vrednotenja

• Funder: Other - Other funder or multiple funders
• Project number: OP20.03520
• Name: Wood Products over a Lifetime
• Acronym: WOOLF