scholarly journals Prediction of Mechanical Properties of Hardwood Species Using the Longitudinal Vibration Acoustic Method

2021 ◽  
Vol 71 (4) ◽  
pp. 391-400
Author(s):  
Kayode Olaoye ◽  
Lawrence Aguda ◽  
Bolade Ogunleye
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Longitudinal Vibration ◽  
Modulus Of Rupture ◽  
Damping Factor ◽  
Acoustic Parameters ◽  
Static Modulus ◽  
Hardwood Species ◽  
Static Modulus Of Elasticity

Abstract Acoustic test methods such as longitudinal vibration have been developed to predict the elastic properties of wood. However, attention has not been shifted to using this method to predict other mechanical properties, especially on Nigeria's preferred, and lesser-used wood species. Thus, we further investigate relationships among mechanical and acoustic properties of selected hardwood species with a view of predicting the mechanical properties of wood from acoustic parameters. Clear wood samples (324) of 20 by 20 by 20 mm3 were collected axially from Albizia adianthifolia, Gmelina arborea, Delonix regia, and Boscia anguistifolia trees, and conditioned before testing. The longitudinal vibration method was adopted to test for the dynamic (acoustic) parameters and properties (fundamental frequency, damping factor, dynamic modulus of elasticity, sound velocity, specific elastic modulus, radiation coefficient, acoustic conversion efficiency, acoustic impedance) while the universal testing machine was used to test for the mechanical properties (static modulus of elasticity, modulus of rupture, maximum compression strength parallel to grain). The damping factor, dynamic modulus of elasticity, and acoustic impedance were the best acoustic parameters that significantly correlated with the static modulus of elasticity (−0.57, 0.81, 0.76), modulus of rupture −0.64, 0.82, 0.85) and maximum compression strength parallel to grain (−0.52, 0.78, 0.84), respectively. There was a significant difference in the mechanical properties with respect to species, thus A. adianthifolia and G. arborea were mechanically better than D. regia and B. anguistifolia for construction or structural purposes. This study revealed that additional new acoustic measures are suitable for inferring mechanical wood properties.

Nondestructive Evaluation of Red Oak and White Oak Species

2020 ◽  
Vol 70 (3) ◽  
pp. 370-377
Author(s):  
Cristian Grecca Turkot ◽  
Roy Daniel Seale ◽  
Edward D. Entsminger ◽  
Frederico José Nistal França ◽  
Rubin Shmulsky
Keyword(s):  
Modulus Of Elasticity ◽  
Longitudinal Vibration ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Red Oak ◽  
Quercus Alba ◽  
White Oak ◽  
Static Modulus ◽  
Static Modulus Of Elasticity ◽  
The Relationship

Abstract The objective of this article is to evaluate the relationship between the dynamic modulus of elasticity (MOEd), which was obtained with acoustic-based nondestructive testing (NDT) methods, and static bending properties of two domestic hardwood oak species. The mechanical properties were conducted using static modulus of elasticity (MOE) and modulus of rupture (MOR) in radial and tangential directions. Mechanical tests were performed according to ASTM D143 on small clear, defect-free specimens from the two tree species: red oak (Quercus rubra) and white oak (Quercus alba). The MOEd was determined by two NDT methods and three longitudinal vibration methods based on the fast Fourier transform. The destructive strength values obtained in this study were within the expected range for these species. The MOE was best predicted by NDT methods for both species but also had a strong capability to predict MOR.

Relativity Analysis between Dynamic and Static Modulus of Elasticity on Different Thickness Wood-Plastic Structural Plates

2011 ◽  
Vol 121-126 ◽  
pp. 4254-4258 ◽  
Author(s):  
Gui Wen Yu ◽  
Ying Cheng Hu ◽  
Ji You Gu
Keyword(s):  
Mechanical Properties ◽  
Nondestructive Testing ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Bending Test ◽  
Three Point Bending ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Static Modulus Of Elasticity ◽  
Different Thickness

The relativity was evaluated between dynamic modulus of elasticity (MOE) and static MOE, in order to assess the potential of using nondestructive testing (NDT) method as a checking tool for mechanical properties of wood-plastic structural plates. The dynamic MOE was evaluated on a FFT system, and the static MOE was determined by three point bending test. All of specimens were made of polyethylene（PE）and poplar flour. A significant correlation between the dynamic MOE and the static MOE was obtained from relativity analysis. These results suggest that the NDT method could be appropriate to estimate the dynamic MOE of specimens with different thickness.

scholarly journals AVALIAÇÃO DE TIPOS DE ONDAS GERADAS POR DOIS MODELOS DE TRANSDUTORES PARA DETERMINAÇÃO DO MÓDULO DE ELASTICIDADE DINÂMICO

FLORESTA ◽  
2010 ◽  
Vol 40 (4) ◽  
Author(s):  
Diego Martins Stangerlin ◽  
Joaquim Carlos Gonçalez ◽  
Raquel Gonçalves ◽  
Elio José Santini ◽  
Leandro Calegari ◽  
...  
Keyword(s):  
Surface Waves ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Ultrasonic Method ◽  
Point Contact ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Ultrasonic Equipment ◽  
The Difference ◽  
Static Modulus Of Elasticity

O objetivo deste estudo foi de avaliar os tipos de ondas gerados por dois modelos de transdutores utilizados para determinação do módulo de elasticidade dinâmico por meio de ensaios com ultrassom e correlacioná-los ao módulo de elasticidade estático obtido por compressão paralela às fibras. Para tanto, utilizou-se um aparelho de ultrassom dotado de transdutores faces planas e de pontos secos com freqüência de 50 kHz. A velocidade ultra-sônica foi determinada ao considerar a transmissão da onda ao longo do comprimento de amostras de madeira com dimensões nominais de 5 x 5 x 20 cm. Para avaliar a sensibilidade do método ultra-sonoro e os tipos de ondas gerados pelos respectivos transdutores, as amostras foram ensaiadas destrutivamente à compressão paralela, com determinação do módulo de elasticidade por ambas metodologias. Apesar da diferença de valores absolutos do módulo de elasticidade entre os ensaios de ultrassom com transdutores faces planas, que geraram ondas longitudinais, e os ensaios de compressão paralela, em função da natureza viscoelástica da madeira, verificou-se uma boa correlação entre os dados. Com relação ao uso dos transdutores pontos secos, que geraram ondas de superfície, não foi verificada boa correlação com os ensaios destrutivos.Palavras-chave:  Ondas longitudinais; ondas de superfície; transdutores de faces planas; transdutores de pontos secos; ensaios não-destrutivos. AbstractEvaluation of wavess generated for two models of transducers for determining the dynamic modulus of elasticity. This study aimed to evaluate the types of waves generated for two transducers used for determining the dynamic modulus of elasticity by tests with ultrasound and to correlate them to the static modulus of elasticity obtained by parallel compression. For this study ultrasonic equipment with planes faces and point-contact transducers of 50 kHz was used. The ultrasonic speed was determined considering the transmission of the wave along the length of the samples with nominal dimensions of 5 x 5 x 20 cm. To evaluate the sensitivity of the ultrasonic method and the types of waves generated for the transducers, samples were submitted to destructive conventional parallel compression, with determination of the elasticity modulus for both methodologies. Although the difference of absolute values between tests of ultrasound with transducers planes faces, that generated longitudinal waves, and parallel compression, due to wood viscoelastic nature, there was a good correlation between the obtained data. It was not observed good correlation between the use of point-contact transducers, which generated surface waves, and the destructive tests.Keywords:Longitudinal waves; surface waves; planes faces transducers; point-contact transducers; not-destructive methods.

scholarly journals MECHANICAL PROPERTIES OF STRUCTURAL AERATED LIGHTWEIGHT CONCRETE REINFORCED WITH IRON LATHING WASTE

2021 ◽  
Vol 25 (01) ◽  
pp. 100-108
Author(s):  
Samer S. Abdulhussein ◽  
◽  
Ashraf A. Alfeehan ◽  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
Hardened Concrete ◽  
Static Modulus ◽  
Flexural Tensile Strength ◽  
Static Modulus Of Elasticity ◽  
The Impact

Currently, the industry of construction requires finding efficient materials to increase the durability and strength as well as decreasing the concrete structure’s total weight. Therefore, an effort was made in this study for examining the impact of adding waste materials such as the iron lathing waste fibers. Iron lathe wastes have been deformed into twisted strips with a width of (4mm) and sieving size of (4.75-10) mm. The experimental investigation has been achieved with the use of four mixes related to light-weight concretes, involving different volumetric ratios of the iron lathing waste fibers as (0%, 1 %, 1.5 %, and 2 %). With the increase in the volume fraction of the lathing waste fibers from 0% to 2%, the results showed that there were a significant increase and improvement in compressive strength, splitting tensile strength, flexural tensile strength, static modulus of elasticity, and dynamic modulus of elasticity by 12%, 67.5%, 134%, 27%, and 26% respectively. This indicates that the iron waste fibers have an important impact in enhancing the mechanical properties of the hardened concrete through the structural change in the concrete matrix.

scholarly journals Durability and Mechanical Performance of Differently Treated Glulam Beams during Two Years of Outdoor Exposure

2020 ◽  
Vol 71 (3) ◽  
pp. 243-252
Author(s):  
Davor Kržišnik ◽  
Miha Humar ◽  
Aleš Straže ◽  
Milan Šernek ◽  
Bogdan Šega ◽  
...  
Keyword(s):  
Modulus Of Elasticity ◽  
Mechanical Performance ◽  
Longitudinal Vibration ◽  
Wood Preservative ◽  
Outdoor Exposure ◽  
Bending Test ◽  
Adhesive Bonds ◽  
Static Modulus ◽  
Outdoor Application ◽  
Static Modulus Of Elasticity

The performance of the composites is influenced by the service life of input raw wood material and used adhesives. The aim of the study was to assess the durability and mechanical performance of glulam beams treated in a different way (thermally modified and/or treated with copper-based wood preservative) and exposed in an outdoor application. Glulam beams (83 mm × 68 mm × 1100 mm), made of three layers of Norway spruce (Picea abies) with PUR adhesives used have been exposed in use class 3.2 in a horizontal position since 4th November 2016. Part of the specimens was equipped with MC sensors. Every year, the degradation was evaluated visually. The dynamic modulus of elasticity was determined by longitudinal vibration, and the static modulus of elasticity using a 4-point bending test. On the smaller specimens, cut from glulams, compressive strength, delamination, and shear strength of adhesive bonds were determined. After two years of exposure, the results indicate that the performance of glulams is determined by the wood modification and applied wood preservative.

Predicting mechanical properties of clear wood from Acacia mangium provenances using ultrasound

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 8309-8319
Author(s):  
Doan Van Duong ◽  
Masumi Hasegawa
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Significant Positive Correlation ◽  
Correlation Coefficients ◽  
Acacia Mangium ◽  
Longitudinal Direction ◽  
Modulus Of Rupture ◽  
Clear Wood

Ultrasound was considered as a means for determining mechanical properties of clear wood in six different Acacia mangium provenances from a trial forest planted in Vietnam. A total of 30 trees (5 trees from each provenance) with no major defects were selected, and a 50-cm-long log was obtained at 1.3 m above the ground from each tree for the assessment of mechanical properties. The measured average ultrasound velocities for provenances tested in the longitudinal direction ranged from 4094 m/s to 4271 m/s. The predicted average dynamic modulus of elasticity (Ed) values varied from 7.42 GPa to 8.70 GPa among provenances. The Ed indicated significant positive correlation coefficients with modulus of elasticity (0.64 to 0.96), modulus of rupture (0.44 to 0.87), and compression strength (0.54 to 0.92) for provenances examined in this study. The results indicated that the use of ultrasound was feasible to determine the mechanical properties of A. mangium provenances planted in Vietnam.

Nondestructive Evaluation of 2 by 8 and 2 by 10 Southern Pine Dimensional Lumber

2020 ◽  
Vol 70 (1) ◽  
pp. 79-87
Author(s):  
Frederico José Nistal França ◽  
Tamara Suely Filgueira Amorim França ◽  
R. Daniel Seale ◽  
Rubin Shmulsky
Keyword(s):  
Mechanical Properties ◽  
Nondestructive Evaluation ◽  
Transverse Vibration ◽  
Dynamic Modulus ◽  
Longitudinal Vibration ◽  
Modulus Of Rupture ◽  
Southern Pine ◽  
The Difference ◽  
Pine Lumber ◽  
Southern Pine Lumber

Abstract This study investigated the use of two nondestructive testing (NDT) methods to evaluate the mechanical properties of No. 2 grade: 2 by 8 and 2 by 10 southern pine lumber. The dynamic modulus of elasticity (dMOE) of each specimen was evaluated nondestructively by using longitudinal vibration and transverse vibration in edgewise and flatwise directions. After the NDT evaluation, the specimens were destructively tested and correlations between static bending MOE with modulus of rupture (MOR) and dMOE were developed. The overall MOE values were 11.14 and 10.96 GPa for 2 by 8 and 2 by 10, respectively. For MOR, the overall value for 2 by 8 was 42.59 MPa, and for 2 by 10 was 43.05 MPa. As expected, results showed statistically significant correlations between static MOE and dMOE (with r ranging from 0.87 to 0.96 for both sizes tested). Also as expected, weaker correlations were found between MOR and the dMOE values (with r ranging from 0.42 to 0.57 for both sizes tested). The lower correlations are largely explained by the difference between the NDT tools analyzing each specimen's global stiffness versus MOR, which is influenced heavily by localized characteristics. Perhaps this finding occurred because larger strength-reducing characteristics are permitted in larger section pieces (2 by 8 vs. 2 by 10) and thus they have opportunity for greater variability. The continuation of studies to develop more reliable NDT is crucial to improve the evaluation of mechanical properties of southern pine lumber and is beneficial to the southern pine timber industry.

Vibration method for grading of large cross-section coniferous timber species

Holzforschung ◽  
2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Francisco Arriaga ◽  
Guillermo Íñiguez-González ◽  
Miguel Esteban ◽  
Ferenc Divos
Keyword(s):  
Natural Frequency ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Longitudinal Vibration ◽  
Strong Relationship ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Timber Species ◽  
Vibration Method ◽  
Dynamic Modulus Of Elasticity

Abstract The non-destructive testing (NDT) of timber using the longitudinal vibration method is based on the natural frequency of wood which is in relation to its quality. In the present paper, the suitability of this tool is investigated and the results of grading 395 pieces are presented. Structural timber of Radiata pine (Pinus radiata D. Don.), Scots pine (Pinus sylvestris L.), and Laricio pine [Pinus nigra ssp. salzmannii (Dunal) Franco] from Spanish sources were investigated. The specimens were tested for bending according to the European standard EN 408 (2003) and the values of strength and stiffness were compared with the results estimated by means of NDT. The vibration equipment applied permits the measurement of the longitudinal natural frequency and mass of the specimen, and then the density and the dynamic modulus of elasticity can be calculated. There is a strong relationship between the static modulus of elasticity obtained from the bending test and the dynamic modulus of elasticity obtained by the NDT technique. There is an acceptable relationship between modulus of rupture and dynamic modulus of elasticity if the visual defects (knot sizes) are taken into account. Acoustic measurements have become widely acceptable, and they have great potential for stress grading of coniferous timber.

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