Longitudinal hardness and Young's modulus of spruce tracheid secondary walls using nanoindentation technique

Wimmer, Rupert; Lucas, B. N.; Tsui, Ting Y.; Oliver, W. C.

doi:10.1007/bf00705928

Cited by 158 publications

(95 citation statements)

References 18 publications

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“…The sample preparation procedure for nanoindentation was similar to that proposed by Wimmer et al (1997). In brief, the bamboo sticks were embedded in Spurr resin and cured in a plastic mold.…”

Section: Sample Preparationmentioning

confidence: 99%

“…The hardness (H IT ) and the elastic modulus (E IT ) of bamboo fiber cell walls were determined using nanoindentation. Nanoindentation is a powerful technique used to directly evaluate the mechanical properties of plant cell walls, first used by Wimmer et al (1997) in the mechanical characterization of wood cell walls. Since then, this technique has found many more applications in the area of wood science and technology, including wood development (Gindl et al 2004), wood fiber composites (Lee et al 2007), and wood adhesion (Konnerth et al 2006(Konnerth et al , 2007.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Moisture Content on the Mechanical Properties of Moso Bamboo at the Macroscopic and Cellular Levels

Wang¹,

Wang²,

Li³

et al. 2013

BioResources

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To better understand how moisture content (MC) affects the longitudinal compressive mechanical properties of bamboo, mechanical tests on both the macroscopic and cellular levels were performed on Moso bamboo (Phyllostachys pubescens Mazei ex H. de Lebaie) at different MCs. At the macroscopic level, the compressive modulus of elasticity (CMOE) was determined using a common mechanical tester, while the indentation modulus of elasticity (EIT) and the hardness (HIT) of the bamboo fiber cell walls were obtained using nanoindentation. The results showed that CMOE, EIT, and HIT were all negatively correlated with the change in MC below the fiber saturation point (FSP) with strong linear relationships. However, the CMOE was found to be more sensitive to a change in MC than was EIT, which indicated that the bamboo was more sensitive to MC at the macro level than at the cellular level, at least in terms of longitudinal compression stiffness. Moreover, EIT was found to be much less sensitive to a change in MC than was HIT, which may explain why the longitudinal compression strength of bamboo was much more sensitive to changes in MC than was the compression modulus of elasticity on the macro scale.

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Section: Sample Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of Moisture Content on the Mechanical Properties of Moso Bamboo at the Macroscopic and Cellular Levels

Wang¹,

Wang²,

Li³

et al. 2013

BioResources

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“…A diferencia, el tablón C mostró lo contrario, con 11.1 GPa en madera temprana y 13.3 GPa en madera tardía y para la lamela media 6.1 y 7.2 GPa. Esta diferencia coincide con la investigación realizada por Wimmer et al (1997), quienes determinaron un módulo de elasticidad para la especie de abeto rojo (Picea rubens), de 13.5 y 21 GPa en la pared celular de madera temprana y tardía, respectivamente. Eder et al (2009) y Cramer et al (2005, a rmaron que el aumento de las propiedades en la madera tardía se asocia al porcentaje de celulosa y a su grado de cristalinidad, puesto que en esta zona (madera tardía) es mayor.…”

Section: Módulo De Elasticidad Obtenido Por Nanoindentacionesunclassified

“…Al igual que en las propiedades mecánicas obtenidas a macroescala, la nanoindentación también muestra diferencias en estas propiedades entre las células de madera tardía y temprana, siendo las propiedades de estas últimas aproximadamente un 50% menor que las células de madera tardía (Eder et al 2009, Cramer et al 2005, Wimmer et al 1997. Por su parte, Wimmer et al (1997), al estudiar la estructura celular de abeto rojo (Picea rubens), lograron establecer que las capas de la pared celular poseen distintas propiedades mecánicas debido a los cambios en la composición química de éstas. La estructura celular de la madera, sus constituyentes poliméricos y la disposición estructural a diferentes niveles de microestructura dan a la madera un comportamiento complejo en el uso de ésta en obras civiles, más aún si ésta se expone a la acción de cargas externas con variaciones de temperatura y contenido de humedad.…”

Section: Introductionunclassified

Determinación de un elemento de volumen representativo de probetas de tablero tensado

Sepúlveda¹,

Gacitúa²,

Bustos³

et al. 2012

Maderas, Cienc. tecnol.

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RESUMENEl objetivo de este estudio fue de nir un elemento de volumen representativo para caracterizar las propiedades mecánicas de probetas de tableros tensados de Pinus radiata D. Don y de Eucalyptus nitens. La determinación del elemento de volumen representativo permitió identi car la sección más pequeña de las probetas que presenta las particularidades de este material compuesto y por consiguiente, representa a la probeta en su conjunto. Para esto, las propiedades nanomecánicas de las paredes celulares y lamela media fueron determinadas por nanoindentaciones. Este estudio se desarrolló en dos etapas. En la primera etapa, el anillo de crecimiento representativo de las piezas de madera bajo compresión perpendicular a la bra, fue determinado. En la segunda etapa, el tablón representativo de la probeta de tablero tensado sometido a compresión a largo plazo, fue determinado. Los resultados de la primera etapa, mostraron que no existe una tendencia especí ca de las propiedades nanomecánicas a través de los anillos de crecimiento en la sección transversal de las piezas de Pinus radiata y Eucalyptus nitens bajo compresión perpendicular a la bra. En la segunda etapa, se estableció que los esfuerzos de compresión a largo plazo en la probeta de tablero tensado principalmente afectaron las propiedades nanomecánicas de la estructura celular de los tablones exterior y central de la probeta. Lo anterior permitió establecer que el elemento de volumen representativo de una probeta de tablero tensado se localizó en la madera temprana del anillo de crecimiento más alejado a la médula en la sección transversal del tablón central. Palabras claves: Propiedades mecánicas, compresión perpendicular, nanoindentaciones, Pinus radiata, Eucalyptus nitens.ABSTRACT e aim of this study was to de ne a representative volume element to characterize the mechanical properties of stress-laminated deck specimens of radiata pine and Eucalyptus nitens. e determination of the representative volume element allowed to identify the smallest representative section of the stress-laminated deck. For this, the nanomechanical properties of the cell walls and middle lamellas were determined by nanoindentations. is study was conducted in two phases. In the rst phase, the growth ring representative of the pieces of wood under compression perpendicular to the grain was determined. In the second phase, the board representative of the stress-laminated deck specimens subjected to long-term compression loads and variable environmental conditions was determined. e results obtained in the rst phase of the study showed that there was no speci c tendency of the nanomechanical properties through growth rings in the cross-section of Pinus radiata

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“…Nanoindentation, a technology that emerged in 1987, is a method for studying objects at super-small scales; it is particularly used to study metal surfaces and extremely thin (film) surfaces [9]. In 1997, it was first used to study the mechanical properties of cell walls in wood materials [10]. Nanoindentation is now being widely used in wood science for such researches as studying the mechanical properties of adhesion layers in wood-based panels [11], the influence of modifications such as heat and chemicals on the mechanical properties of wood cell walls [12][13] and the cell walls of agricultural crop stalks [14], hardwoods [15], and softwoods [10].…”

mentioning

confidence: 99%

Influence of the Mechanical Properties of Tobacco Stalk Fiber Cell Wall on Particleboard Panels

Li¹,

Wu²,

Yu³

2014

AMSA

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Abstract-Natural fibers are used to improve mechanical properties of composites materials; research into the influence of the mechanical properties of various fibers' cell walls on the mechanical properties of composites is very important for producing highquality composites. The aim of this research is to study the influence of the mechanical properties of tobacco stalk fiber cell wall on the mechanical properties of particle-based panels, comparing the properties of particleboards made with tobacco stalks from different parts of the stem (bottom, midpoint, and top) and treated tobacco stalks from the midpoint of the stem with 1% NaOH solution at 100℃ for 0, 30, 60, and 90 mins, respectively. The results show that the mechanical properties of tobacco stalk fiber cell walls from different parts of the stalk differ and are reduced after the tobacco stalk is treated with 1% NaOH solution. The mechanical properties of the tobacco stalk-based particleboard panels were negatively correlated with the mechanical properties of the tobacco stalk fiber cell wall. After the 1% NaOH treatments of 0-60 min, the middle lamellae were broken, and the mechanical properties of the particleboard were improved; after the 1% NaOH treatment of 90 min, the fiber cell walls were broken and the MOR and MOE of the panels were reduced. Thus, it was concluded that the mechanical properties of fiber cell wall can be reduced to improve the mechanical properties of particleboard panels. The improvement of the mechanical properties of particleboard with no-added-Formaldehyde resin by reducing the mechanical properties of fiber cell wall will be studied in future.

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Longitudinal hardness and Young's modulus of spruce tracheid secondary walls using nanoindentation technique

Cited by 158 publications

References 18 publications

Effects of Moisture Content on the Mechanical Properties of Moso Bamboo at the Macroscopic and Cellular Levels

Effects of Moisture Content on the Mechanical Properties of Moso Bamboo at the Macroscopic and Cellular Levels

Determinación de un elemento de volumen representativo de probetas de tablero tensado

Influence of the Mechanical Properties of Tobacco Stalk Fiber Cell Wall on Particleboard Panels

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