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.

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 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.

scholarly journals Influence of Hybrid Fibers on Toughness Behavior of High Strength Flowing Concrete

2011 ◽  
Vol 57 (3) ◽  
pp. 249-260 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Hybrid Composite ◽  
High Strength ◽  
Steel Fibers ◽  
Hybrid Fibers ◽  
Static Modulus ◽  
Static Modulus Of Elasticity ◽  
Strength And Toughness

Abstract This study investigates the use of steel fibers and hybrid composite with a total fibers content of 2% on the high strength flowing concrete and determines the density, compressive strength, static modulus of elasticity, flexural strength and toughness indices for the mixes. The results show that the inclusion of more than 0.5% of palm fibers in hybrid fibers mixes reduces the compressive strength. The hybrid fibers can be considered as a promising concept and the replacement of a portion of steel fibers with palm fibers can significantly reduce the density, enhance the flexural strength and toughness. The results also indicates that the use of hybrid fibers (1.5 steel fibers + 0.5% palm fibers) in specimens increases significantly the toughness indices and thus the use of hybrid fibers combinations in reinforced concrete would enhance their flexural toughness & rigidity and enhance their overall performances

Modeling temperature effect on dynamic modulus of elasticity of red pine (Pinus resinosa) in frozen and non-frozen states

Holzforschung ◽  
2015 ◽  
Vol 69 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Shan Gao ◽  
Xiping Wang ◽  
Lihai Wang
Keyword(s):  
Temperature Effect ◽  
Modulus Of Elasticity ◽  
Freezing Point ◽  
Red Pine ◽  
Analytical Models ◽  
Clear Wood ◽  
Green Wood ◽  
Static Modulus ◽  
Static Modulus Of Elasticity ◽  
Increasing Temperature

Abstract The response of dynamic and static modulus of elasticity (MOEdyn and MOEsta) of red pine small clear wood (25.4×25.4×407 mm3) within the temperature range -40 to 40°C has been investigated. The moisture content (MC) of the specimens ranged from 0 to 118%. The MOEdyn was calculated based on measured ultrasonic velocity (V) and wood density. The MOEsta was measured by static bending tests in a climate chamber between -40 and 40°C. The results indicate that both MOEdyn and MOEsta were affected by temperature and the MC. Above freezing point, MOE decreased linearly at a slow rate with increasing temperature. Below freezing point, MOE increased at a rapid rate with decreasing temperature. The MC-level had a significant effect on the MOE-temperature relationships. Temperature effect was much more significant in green wood than in dry wood. Analytical models were developed to predict the change of MOEdyn relative to that at 20°C in the case of acoustic measurements under different temperature conditions.

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