Nondestructive Evaluation of a Tropical Hardwood: Interrelationship Between Methods and Physical-Acoustical Variables

Teles, Ricardo Faustino; Menezzi, Cláudio Henrique Soares Del; Souza, Frederico de; Souza, Mário Rabelo de

doi:10.12953/2177-6830.v02n01a01

Cited by 27 publications

(20 citation statements)

References 12 publications

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“…Generally, the values obtained through stress wave method were higher than static values. Several studies have reported that values of dynamic modulus of elasticity are often higher than those obtained using static bending tests (Teles et al 2011;Passialis and Adamopoulos 2002;Barrett et al 2008). The lower static MOE values were expected because static measurement includes shear deflection, whereas MTG results are essentially shear free MOE values (Barrett et al 2008).…”

Section: Resultsmentioning

confidence: 99%

“…Divos and Tanaka (2005) reported that R 2 values between static and dynamic MOE values can be between 0.9 and 0.96, and dynamic MOE values are usually 10% higher than the static MOE values. Biechele et al (2010) have reached the coefficient of determination values of 0.80 and 0.97 for spruce timber using stress wave and transverse vibration methods, respectively, while Teles et al (2011) have reported the coefficient of determination values of 0.84 and 0.94 for tropical hardwood species using same methods. Ravenshorst and van de Kuilen (2006) evaluated bending properties of 30 different hardwood species using both destructive and nondestructive testing.…”

Section: Resultsmentioning

confidence: 99%

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Prediction of Bending Properties for Turkish Red Pine (Pinus brutia Ten.) Lumber using Stress Wave Method

Güntekin¹,

Emiroglu²,

Yılmaz³

2012

BioResources

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Bending properties of Turkish red pine (Pinus brutia Ten.) lumber pieces were predicted using the stress wave method. The lumber samples were taken from 30-to 80-year-old red pine trees harvested from a southwest site in Turkey. MTG timber grader was utilized to predict modulus of elasticity (MOE) and modulus of rupture (MOR) values of lumbers with 40 mm x 90 mm in cross section and 3 meters in length. Static MOE and MOR values of the lumber pieces were determined using a three-point bending test. The coefficient of determination between measured and predicted MOEs was 0.84 and that between dynamic MOE and bending strength was 0.69. However, the coefficient of determination between bending MOE and strength was only 0.45. It seems that dynamic MOE has better prediction capability for bending strength than static MOE. Effects of some variables such as log and visual grades on dynamic MOE values were also determined statistically. Natural frequency of the lumbers showed far more significant effects than other variables. It is apparent that the stress wave method has the potential to predict the bending properties of Turkish red pine lumber.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Prediction of Bending Properties for Turkish Red Pine (Pinus brutia Ten.) Lumber using Stress Wave Method

Güntekin¹,

Emiroglu²,

Yılmaz³

2012

BioResources

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“…The strength of correlation is dependent on the species and the method used (Karlinasari et al 2008, Ravenshorst et al 2008, Teles et al 2011.…”

Section: Universidad Del Bío -Bíomentioning

confidence: 99%

“…These methods apply a close correlation between the dynamic and the static modulus of elasticity values which was proved for sound wood in different states such as timber (Hassan et al 2013), logs (Zhou et al 2013) or Laminated Veneer Lumber (Wang et al 2003) and decayed wood as well . Few studies deal with different tropical species such as Sextonia rubra for which nondestructive methods were used for predicting the stiffness of lumber with very high accuracy (r = 0,91 for stress wave method) (Teles et al 2011). Karlinasari et al (2008) showed a strong relation between the static and the ultrasound dynamic moduli of elasticity for small clear specimens of four tropical hardwoods (r=0,82), on the other hand, lower values were found when species were evaluated individually.…”

Section: Introductionmentioning

confidence: 99%

Prediction of mechanical properties - modulus of rupture and modulus of elasticity - of five tropical species by nondestructive methods

Baar

Tippner

Rademacher

2015

Maderas, Cienc. tecnol.

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This paper analyzes the usability of different dynamic moduli of elasticity and wood density for the prediction of mechanical properties -static modulus of elasticity and modulus of rupture -in samples with grain deflection from the longitudinal direction. Five tropical hardwoods (Afzelia bipindensis, Intsia bijuga, Millettia laurentii, Astronium graveolens and Microberlinia brazzavillensis) with different grain characteristics were used for this purpose. The fiber deflection was caused by the presence of interlocked grain or the working process. The three nondestructive techniques used in this study -longitudinal and flexural resonance method and ultrasound method -provided higher values of modulus of elasticity than the static bending test, but close correlation was observed between these variables. The weakest correlation was found for the ultrasound method which is probably caused by its measuring mechanism. The prediction of the modulus of rupture is less accurate when the dynamic modulus of elasticity is compared with the static modulus of elasticity; on the other hand, it was still good in comparison with the density model, which is inapplicable when grain deflection occurs in wood. In the wood of Zebrano where the interlocked grain was strongly developed, almost all of the correlation coefficients showed the lowest values and the prediction of modulus of rupture by nondestructive techniques was unsatisfactory.

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“…There is a contradiction in the literature on whether SV is correlated with wood density or not. Some authors (Oliveira et al 2002;Ilic 2003;Teles et al 2011) determined that there is no relationship between density and velocity, while others (Oliveira and Sales 2006;Baradit and Niemz 2012) reported a positive relationship between density and velocity. Some authors (Ilic 2003;Krauss and Kúdela 2011) claim that velocity is related to the micro-fibrillar angle, while Gerhards (1982b) and Beall (2002) pointed out that grain angle has a major impact on the SV.…”

Section: Resultsmentioning

confidence: 99%

Prediction of Compression Properties in Three Orthotropic Directions for Some Important Turkish Wood Species Using Ultrasound

Güntekin¹,

Aydın²,

Niemz³

2015

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Compression properties in three orthotropic directions for some important Turkish wood species, including Calabrian pine (Pinus brutia Ten.), Taurus cedar (Cedrus libani), Oriental beech (Fagus orientalis), and sessile oak (Quercus petraea), were studied using non-destructive and destructive techniques. The materials used in the study consisted of 720 small clear specimens of nominal dimensions of 20 x 20 x 60 mm. The influence of equilibrium moisture content (EMC) was studied over four batches of 15 specimens each, conditioned for six to eight weeks before testing at a temperature of 20 ± 2 °C and at four different relative humidity conditions (50%, 65%, 85%, and 95%). Time of flight values were measured with a commercial ultrasonic tester. Using the time results from the ultrasound device, the wave velocities (length/time) and Edyn values were calculated. Samples were also tested in uniaxial compression to determine the Young's modulus and compression strength values in three orthotropic directions. The Edyn correlated well with the Young's modulus and compression strength of the specimens; coefficients of determination ranged between 0.75 and 0.96. Moisture content seems to have more influence than density on sound velocities. Results showed that there is a weak and mostly negative correlation between the density of the specimens and the sound velocity values.

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Nondestructive Evaluation of a Tropical Hardwood: Interrelationship Between Methods and Physical-Acoustical Variables

Cited by 27 publications

References 12 publications

Prediction of Bending Properties for Turkish Red Pine (Pinus brutia Ten.) Lumber using Stress Wave Method

Prediction of Bending Properties for Turkish Red Pine (Pinus brutia Ten.) Lumber using Stress Wave Method

Prediction of mechanical properties - modulus of rupture and modulus of elasticity - of five tropical species by nondestructive methods

Prediction of Compression Properties in Three Orthotropic Directions for Some Important Turkish Wood Species Using Ultrasound

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