Strength properties of laminated veneer lumber in compression perpendicular to its grain

Ido, Hirofumi; Nagao, Hirofumi; Kobayashi, Hideo; Miyatake, Atsushi; Hiramatsu, Yasushi

doi:10.1007/s10086-010-1116-3

Cited by 14 publications

(11 citation statements)

References 1 publication

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“…The results obtained in this study were also seen in Norway spruce (Picea abies) [22] and hinoki (C. obtusa) [23]. In contrast, σ e5% under loading in the tangential direction was larger than that under loading in the radial direction in four coniferous tree species [5]. As the reason for the larger σ e5% under loading in the tangential direction, it was considered that vertically lined latewood protected the weak earlywood from being crushed [5].…”

Section: Discussionsupporting

confidence: 71%

“…In contrast, σ e5% under loading in the tangential direction was larger than that under loading in the radial direction in four coniferous tree species [5]. As the reason for the larger σ e5% under loading in the tangential direction, it was considered that vertically lined latewood protected the weak earlywood from being crushed [5]. In the Japanese larch (Larix kaempferi), the σ e with loading in the tangential direction increased with density; however, the σ e with loading in the radial direction did not correlate with density [24].…”

Section: Discussionmentioning

confidence: 63%

“…In five coniferous tree species, the σ e of timber with loading in the tangential direction was larger than that with loading in the radial direction except in the case of radiate pine (Pinus radiata) [5]. In a previous study [3], sugi boards with pith and without pith used in laminated lumber (prototype bed sill) were loaded in the tangential direction except near the pith and radial direction respectively, because these boards were edge-grain boards and flat-grain boards respectively.…”

Section: Introductionmentioning

confidence: 92%

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Partial compression strength of sugi (Japanese cedar, Cryptomeria japonica) wood near the pith perpendicular to the grain

et al. 2019

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It was reported that sugi (Japanese cedar, Cryptomeria japonica) boards with pith had a greater partial compression strength perpendicular to the grain (σ e) than sugi boards without pith. However, the reason for the superior strength of sugi boards with pith remains unclear. In this study, as the first step to elucidate the reason, we report the effects of loading direction (tangential and radial), density, microfibril angle (MFA) of earlywood and latewood tracheids, latewood tracheid length and cross-sectional parameters of earlywood tracheids (CE) on σ e in sugi wood. There was no significant effect of loading direction on σ e , and the specimens with pith had significantly larger σ e values than the specimens without pith. A larger density, larger MFA, and smaller cross-sectional dimensions with a square shape in earlywood tracheids significantly increased σ e in the radial loading direction. By multiple linear regression, it was recognized that density and MFA was the effective parameters, and MFA had a larger effect than did density in the predictor equation for σ e. This is the first study that reported the positive effects of MFA on σ e in sugi wood.

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Section: Discussionsupporting

confidence: 71%

Section: Discussionmentioning

confidence: 63%

Section: Introductionmentioning

confidence: 92%

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Partial compression strength of sugi (Japanese cedar, Cryptomeria japonica) wood near the pith perpendicular to the grain

et al. 2019

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“…There is much less latewood than earlywood in corewood, but with its smaller cell lumen and thicker cell walls, latewood resists buckling and crushing failure more than early wood [67]. The tighter radius growth rings in the pith samples contribute to the higher strength in clear and resin samples because the latewood acts as a pillar and protects the weaker earlywood from crushing [68] and from dependence on rolling shear properties which are weaker than CPerpG properties [36]. Kijidani, et al [69] also found higher CPerpG strength values for pith samples in Sugi wood and although they could not conclude the reason, they did find correlations with high microfibril angle, increased density in the pith samples as well as cellular structure.…”

Section: Effect Of Pithmentioning

confidence: 99%

Mechanical Properties of Low-Stiffness Out-of-Grade Hybrid Pine—Effects of Knots, Resin and Pith

Cherry

Karunasena

Manalo

2022

Forests

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Out-of-grade pine timber is an abundant material resource that is underutilised because its mechanical properties are not well understood. Increasing trends toward shorter rotation times and fast-grown plantation pines around the world such as Pinus elliottii x P. caribaea var. hondurensis hybrid (PEExPCH) mean low-stiffness corewood is becoming a larger portion of this out-of-grade population. This study characterised the modulus and strength properties in bending, compression parallel to grain (CParG) and compression perpendicular to grain (CPerpG), shear and tension strength of low-stiffness out-of-grade PEExPCH. The effect of resin, knots and pith on these properties were also investigated. The results show that in clear wood, the MOE in bending, CParG, CPerpG and shear modulus are 6.9 GPa, 5.78 GPa, 0.27 GPa and 0.59 GPa, respectively, while strengths are 45.8 MPa, 29.4 MPa, 6.7 MPa, 5.7 MPa, respectively. The tensile strength is 32.4 MPa. Resin significantly increased density 45% higher than clear, but performed similar with the exception of CPerpG MOE and strength which were significantly different. Resin area ratio (RAR) has a moderate correlation with density with an R2 of 0.659 but low to no correlation for mechanical properties. Knots were significantly different to clear for all test types and within a range of 48% to 196%. Knots were high in CPerpG MOE and strength but lower for all other properties and had the largest negative impact on tensile strength. Knot area ratio (KAR) had low to moderate correlation with tension strength and CPerpG MOE with R2 of 0.48 and 0.35, respectively. Pith was within the range of 76% to 121% of non-pith samples for structural performance, some of which were significantly different, and pith samples were higher in density than non-pith. This new information is crucial for the effective establishment of grading rules, design optimisation and utilisation of low-stiffness out-of-grade PEExPCH as a new material resource in civil engineering applications.

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“…Poplar laminated veneer lumber (LVL) sheets are fabricated by hotpressing poplar veneer. Because of its excellent physical and mechanical properties, LVL has been applied widely to wooden-structured buildings and is suitable for the development of green and prefabricated buildings [5][6][7][8]. Microscopic and macroscopic defects or damage (cracks) naturally occur in wood [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of Mode-I and Mode-II Interlaminar Fracture Characteristics of Poplar LVL

Xiao¹,

Li²,

Shu³

et al. 2023

Journal of Renewable Materials

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Fracture is a common failure form of poplar laminated veneer lumber (LVL). In the present work, we performed an experimental study on the mode-I along-grain interlaminar fracture, mode-I cross-grain interlaminar fracture, and mode-II interlaminar fracture of poplar LVL. We investigated stress mechanisms, failure modes, and fracture toughness values of the different fracture types. The experimental results revealed that the crack in the mode-I along-grain interlaminar fracture specimen propagated along the prefabricated crack direction, and the crack tip broke. The mode-I cross-grain interlaminar fracture specimen had cracks in the vertical direction near the prefabricated crack. In the mode-II interlaminar fracture specimen, cracks appeared along the initial prefabricated crack direction. The load-displacement curves of these three specimens were linear in the early stage of loading. With the increase in the load, a nonlinear segment appeared before crack propagation and a descending segment appeared after crack propagation. The nonlinear segments of the mode-I along-grain interlaminar fracture and mode-II interlaminar fracture were very short, and cracks expanded quickly after their initiation, resulting in brittle fracture. The nonlinear segment of the mode-I cross-grain interlaminar fracture was long, resulting in plastic failure. The average toughness values of the mode-I along-grain interlaminar fracture, mode-I cross-grain interlaminar fracture, and mode-II interlaminar fracture were 15.43, 270.15, and 39.72 MPa•mm 1/2 , respectively.

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Strength properties of laminated veneer lumber in compression perpendicular to its grain

Cited by 14 publications

References 1 publication

Partial compression strength of sugi (Japanese cedar, Cryptomeria japonica) wood near the pith perpendicular to the grain

Partial compression strength of sugi (Japanese cedar, Cryptomeria japonica) wood near the pith perpendicular to the grain

Mechanical Properties of Low-Stiffness Out-of-Grade Hybrid Pine—Effects of Knots, Resin and Pith

Experimental Study of Mode-I and Mode-II Interlaminar Fracture Characteristics of Poplar LVL

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