Mechanical Characterization of Iroko Wood Using Small Specimens

Cunha, Carlos Manuel F. da; Tenório, Marina; Lima, Daniel F.; Rebouças, Arthur da Silva; Neves, Luís; Branco, Jorge M.

doi:10.3390/buildings11030116

Cited by 8 publications

(7 citation statements)

References 12 publications

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“…A total of 132 small clear wood specimens with the dimensions of 10 mm x 10 mm x 200 mm (radial x tangential x longitudinal) were cut and prepared at the SerQ -Innovation and Competence Forest Centre. The idea of using small clear wood specimens is because they allow the results can be more safely compared to other wood species (Melo et al 2015, Lorenzo andMuñoz 2018), allowing better workability, they are simple to obtain, economically attractive, rapid to condition, and straightforward in tests, for example, mechanical ones (Cunha et al 2021, Krajnc et al 2019.…”

Section: Methodsmentioning

confidence: 99%

Effect of microwave treatment on drying and water impregnability of Pinus pinaster and Eucalyptus globulus

Mascarenhas

Dias

Christofóro³

et al. 2022

Maderas, Cienc. tecnol.

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Wood is a material that has been used by humankind for a long time. However, wood researchers and industry have always been concerned about the issues during wood drying and the permeability problems of certain species. In this sense, microwave technology has been applied for wood drying and improving permeability. This paper investigates the microwave drying of two Portuguese wood species, Pinus pinaster sap and heartwood, and Eucalyptus globulus heartwood using small clear specimens. The samples were grouped into six during each microwave treatment run according to their similarity of initial moisture content. Once the drying was completed, control and microwave-treated samples were impregnated with desalinated water to analyze their improvement in water absorption, and the compression strength parallel to the grain was analyzed. The results showed that each wood species behaves differently under microwave drying and initial moisture content. The impregnation results demonstrated that pine and Eucalyptus microwave-treated heartwood samples improved their capability to absorb water. Finally, only the microwave-treated specimens of Eucalyptus heartwood presented a decrease in the values of compression strength parallel to the grain compared to the control group. Therefore, MW treatment presents possibilities for further applications for the wood industry with supporting results.

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Section: Methodsmentioning

confidence: 99%

Effect of microwave treatment on drying and water impregnability of Pinus pinaster and Eucalyptus globulus

Mascarenhas

Dias

Christofóro³

et al. 2022

Maderas, Cienc. tecnol.

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“…The behaviors of wood behaviors are described using the engineering constants such as the modulus of elasticity (MOE) in the longitudinal, radial, and tangential directions (Ex; Ey; Ez), shear modulus (Gxy, Gxz, Gyz), and Poisson's ratio. The wood material properties adopted from literature reports (Cunha et al, 2021;Green et al, 2019) and the authors' research. where σw,t, and σw,c are the timber tensile and compressive stress; Ew is the timber modulus of elasticity; εw,t and εw,c are the tensile and compressive strain in timber; and εw,cy is the strain value at yield stress σw,cy.…”

Section: Numerical Analysismentioning

confidence: 99%

Experimental and numerical investigation of flexural properties of larch beams reinforced with different layer numbers

Şimşek Türker,

Kılınçarslan

2024

RDLC

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Recent applications demonstrated how fiber-reinforced polymer (FRP) composites can improve the structural capabilities of glulam beams, particularly regarding their flexural and shear strength. With the development of precise numerical models, such systems can be optimized. There is currently a dearth of information in the literature on numerical models that can accurately anticipate the nonlinear behavior of low-grade glued laminated timber beams reinforced with FRP. In this study, larch beams were reinforced with carbon fiber reinforced polymer fabric 1, 2 and 3 layers. The effect of the number of floors on the flexural properties of the beams in reinforcement was investigated experimentally and numerically. As a result of the study, the best flexural properties were achieved with 3-layer reinforcement. It was observed that 1- and 2-layer reinforcement compared to the reference beam were also significantly effective. Numerical analyzes gave close values with experimental test results. As a result of comparing the results obtained from the numerical model with the experimental findings, it was concluded that the FRP fabric managed to significantly increase the performance of larch timber. The model is a useful tool for examining the effect of reinforcement coefficient and will be used for optimization of the larch beam.Recent applications demonstrated how fiber-reinforced polymer (FRP) composites can improve the structural capabilities of glulam beams, particularly regarding their flexural and shear strength. With the development of precise numerical models, such systems can be optimized. There is currently a dearth of information in the literature on numerical models that can accurately anticipate the nonlinear behavior of low-grade glued laminated timber beams reinforced with FRP. In this study, larch beams were reinforced with carbon fiber reinforced polymer fabric 1, 2 and 3 layers. The effect of the number of floors on the flexural properties of the beams in reinforcement was investigated experimentally and numerically. As a result of the study, the best flexural properties were achieved with 3-layer reinforcement. It was observed that 1- and 2-layer reinforcement compared to the reference beam were also significantly effective. Numerical analyzes gave close values with experimental test results. As a result of comparing the results obtained from the numerical model with the experimental findings, it was concluded that the FRP fabric managed to significantly increase the performance of larch timber. The model is a useful tool for examining the effect of reinforcement coefficient and will be used for optimization of the larch beam.

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“…Reduction factors are derived from these data, as the ratio between the mean values of the small clear data and the characteristic values from the structural size data. However, Cunha et al (2021), stated that the results of some studies show that for the same wood species, but different countries of origin, similar mean values of bending strength can be obtained for small clear specimens, but noticeable differences appear when testing structural size specimens. With this in mind, the previously mentioned authors examined the possibilities of characterizing mechanical properties only by testing small specimens, in order to eliminate the need to test specimens of structural sizes of similar tree species.…”

Section: Introductionmentioning

confidence: 99%

“…Several recent studies have addressed the relationships between MOE and MOR of small clear specimens and structural size specimens (Butler et al 2016;Krajnc et al 2019;Nowak et al 2021). Cunha et al (2021), went a step further and examined the possibilities for characterizing mechanical properties only through small clear specimens. Namely, according to SRPS EN 384 (2019), the characteristic values of MOE and MOR can be determined by testing small clear specimens only if both small and structural size data are available for at least three similar species.…”

Section: Introductionmentioning

confidence: 99%

“…The available literature on the impact of loading rates on MOE and MOR refers only to the mean values, and not to the whole distribution of these mechanical properties of wood. However, if it is of interest to carry out the procedure proposed by the work of Cunha et al (2021), i.e., if it is necessary to determine the 5 th percentile of the small clear specimens, then the impact of the loading rate on the whole distribution of MOE and MOR and not only on the mean values should also be examined. Especially because the ISO 13061-3 (2015) and ISO 13061-4 (2015) standards allow a greater "freedom" in the choice of loading rate when examining MOE and MOR than the SRPS EN 408 (2014) standard.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Loading rate effects on MOE and MOR distributions in testing of small clear beech wood specimens

Mihailović

Miric-Milosavljević

Djurković

et al. 2022

BioRes

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Distributions of the modulus of elasticity (MOE) and modulus of rupture (MOR) were characterized at three loading rates for small clear beech specimens in static bending. The correlation between MOE and MOR for all three loading rates was significant, but it weakened with increasing load rates. The analysis of the characteristics of empirical distributions, as well as the preliminary selection of the theoretical distributions for MOE and MOR, were performed on the basis of L-moments and L-moment diagrams. According to the standard for testing small specimens, MOE and MOR are determined as the arithmetic mean of the sample. Usage of the arithmetic mean is justified when the analyzed quantity is symmetrically distributed. It was found that the distribution of MOE and MOR is not always symmetric. The loading rate influences the shapes of the MOE and MOR empirical distributions, and consequently the choice of theoretical distribution. The general extreme value distribution stood out as the best one for both MOE and MOR, regardless of the loading rate, and the second overall ranked distribution is the three-parameter Weibull distribution. The loading rate affected the value of the fifth percentile in MOR, when determined from both the empirical and theoretical distributions.

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Mechanical Characterization of Iroko Wood Using Small Specimens

Cited by 8 publications

References 12 publications

Effect of microwave treatment on drying and water impregnability of Pinus pinaster and Eucalyptus globulus

Effect of microwave treatment on drying and water impregnability of Pinus pinaster and Eucalyptus globulus

Experimental and numerical investigation of flexural properties of larch beams reinforced with different layer numbers

Loading rate effects on MOE and MOR distributions in testing of small clear beech wood specimens

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