Relationships between wood properties of small clear specimens and structural-sized boards in three softwood species

Holzforschung ◽  
2019 ◽  
Vol 73 (11) ◽  
pp. 987-996
Author(s):  
Luka Krajnc ◽  
Niall Farrelly ◽  
Annette M. Harte

Abstract Research on the mechanical and physical properties of wood is commonly carried out on either small clear specimens or structural-sized boards. The first approach was more frequently utilized in the past, while the latter is more commonly used nowadays. However, there is very little information on how the two approaches relate with one another. This study aimed to quantify the relationships between the mechanical [modulus of elasticity (MOE) and bending strength] and physical properties (density) of both specimen sizes. A total of 1376 structural-sized boards from three different species (Douglas-fir, Norway spruce and Sitka spruce) were tested in bending, after which a small clear specimen was extracted from the undamaged portion of each board and re-tested in bending. Prior to destructive testing, all boards and clear specimens were evaluated using non-destructive technology. Poor-to-moderate relationships were found between all measured mechanical and physical properties of structural-sized timber and small clear specimens. In both specimen sizes, the properties correlated with one another within the same specimen size, as well as across the two sizes. The strength of correlations appears to be somewhat species dependent. Relatively good relationships were identified when comparing the mean tree values of the properties examined, suggesting either method can be used for a tree-level comparison. The non-destructive evaluation of specimens was shown to reflect the measured properties moderately well, with the relationships changing significantly depending on which measured property was being predicted.

2017 ◽  
Vol 52 (1) ◽  
pp. 49-52
Author(s):  
Elias ◽  
AK Das ◽  
MM Rahman ◽  
MA Islam

This research intends to explore the mechanical and physical properties of waterlogged rain tree (Samanea saman). The variation of mechanical and physical wood properties grown in waterlogged and non-waterlogged area were studied. Four trees of the species were selected from two areas. Important mechanical and physical properties were examined for the wood of two types of trees Oven dry density for the wood of waterlogged tree was 420 kg/m3 whether it was 550 kg/m3 for the wood of non-waterlogged tree. The MOR of wood of waterlogged tree was 58.2 N/mm2 and wood of non-waterlogged tree produced 78.1 N/mm2. The MOE of the wood of waterlogged tree and non-waterlogged tree were 1478 and 4876 N/mm2. The physical and mechanical properties were lower for the wood of waterlogged tree. Such findings may in proper uses of the species.Bangladesh J. Sci. Ind. Res. 52(1), 49-52, 2017


2018 ◽  
Vol 28 (4) ◽  
pp. 138-148
Author(s):  
Arkadiusz Denisiewicz ◽  
Tomasz Socha ◽  
Krzysztof Kula ◽  
Marcin Pasula

Abstract The article presents results of laboratory tests of selected mechanical and physical properties of fine-grained fiber concrete. Tests were conducted on samples with a different degree of reinforcement made on the basis of steel and polypropylene fibers. For the designed concrete mixtures and prepared samples, slump class, shrinkage, compressive and bending strength and water tightness were determined.


2013 ◽  
Vol 8 ◽  
pp. 35-44 ◽  
Author(s):  
Emilia Vasanelli ◽  
Maria Sileo ◽  
Angela Calia ◽  
Maria Antonietta Aiello

2014 ◽  
Vol 92 ◽  
pp. 194-202 ◽  
Author(s):  
Semra Kurama ◽  
Elif Eren Gültekin

Non-destructive testing techniques are widely used for testing ceramic materials. In our studies, two different types of ultrasonic test methods (A-scan and C-Scan) were investigated as non-destructive testing methods for characterization of porcelain tiles. Tiles were sintered in different temperatures to change their porosity and density properties. By changing of ultrasonic time and velocity related with samples’ some physical properties (such as bulk density, apparent density, apparent porosity (%), water absorption (%)) inspected via contact A-scan ultrasonic test method. The results show that without necessity of traditional test methods, some physical properties of ceramics can be determined by using obtained ultrasonic velocity-bulk density, apparent density, apparent porosity (%) and water absorption (%) calibration plots. Additionally, various defects were inspected in samples by using water immersion ultrasonic C-scan method. These results supported this study to obtain the information about defects’ size and place in the ceramic tiles. To support this non-destructive method results scanning electron microscope (SEM) characterization was done and images give the information about the place of the defect.


2019 ◽  
Vol 105 ◽  
pp. 113-124
Author(s):  
ANITA WRONKA ◽  
GRZEGORZ KOWALUK

Selected properties of particleboard made of raspberry Rubus idaeus L. lignocellulosic particles. The aim of the research was to confirm the possibility of using lignocellulosic particles of raspberry Rubus idaeus L. stalks as an alternative raw material in particleboard technology. Within the scope of work, it was to produce particleboards from raspberry lignocellulosic particles in laboratory conditions, and to investigate selected mechanical and physical properties of the produced boards. In addition to the aforementioned tests, the characterization of the lignocellulosic raw material used in the tests (density, bark share, fractional composition) was carried out. The tests have shown that it is possible to produce the furniture particleboards with use the lignocellulosic particles of raspberry Rubus idaeus L. To meet the requirements of the European standards for furniture panels, such particleboards must contain less than 50% of raspberry particles with density 650 kg/m3 (due to the bending strength criterion).


Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 189-195 ◽  
Author(s):  
B. Clair ◽  
J. Ruelle ◽  
B. Thibaut

Summary A range of mechanical and physical properties were determined for 96 specimens of chestnut wood and for wood types ranging from compression to tension wood; tests included (1) growth stress, (2) longitudinal Young's modulus in green and air-dried states (3) shrinkage in longitudinal and tangential directions. Anatomical observations permitted determination of the proportion of fibres with a gelatinous layer. The influence of these atypical fibres on macroscopic wood properties is examined and discussed. A basic model is proposed to determine their properties in theoretically isolated conditions.


2021 ◽  
Vol 97 (01) ◽  
pp. 52-64
Author(s):  
James D. Stewart ◽  
Ross Koppenaal ◽  
Antoine Lalumière ◽  
Roger J. Whitehead

Upstream identification of wood properties using non-destructive testing methods such as acoustic velocity (AV) measurements is important for optimizing allocation of wood to mills or products. We evaluated the effectiveness of field AV measurement tools in predicting lodgepole pine wood stiffness (modulus of elasticity, MOE) as measured by Silviscan on wood samples. AV was measured on trees and logs from six sites in Alberta and British Columbia. We evaluated the effect on MOE estimation of calculating averages of the adjustment factor k and of green density (GD) at different spatial scales from individual tree to population. The effect of using forest inventory variables on MOE prediction were also examined. Prediction of tree-level MOE from tree-level measurements of AV, k and GD resulted in R2 values of 0.59. Using estimates of k and GD averaged at plot, site or population scales significantly diminished the R2 of the MOE predictions at tree level. Predicting MOE at plot or stand level from corresponding averages of AV, k and GD gave R2 values >0.8. Including inventory variables in tree-level MOE predictions increased the R2 to 0.62. AV measurements can give operationally useful estimates of MOE in lodgepole pine trees at the stand level.


2013 ◽  
Vol 812 ◽  
pp. 169-174
Author(s):  
Azizul Ishak ◽  
Siti Rafedah A. Karim ◽  
Hashim W. Samsi

The objective of this study is to determine the mechanical and physical properties of Particleboard made from modified particle of Kelampayan (Neolamarckia cadamba). The particles were modified with Silane and Sodium Hydroxide (NaOH) by soaked the particle for 24 hours with different ratio ( Kelampayan + Silane, Kelampayan + NaOH, and Kelampayan + Silane + NaOH). The result showed that the mechanical and dimensional stability of the treated wood were improved. Particleboard made from 0.8 mesh particles treated with Silane and NaOH were highest value of bending strength modulus of rapture (MOR) 22.89MPa, modulus of elasticity (MOE) 3916.88MPa and Internal Bond properties 0.48214 MPa whereby particleboard made from 0.5 mesh particles treated by Silane were highest value for bending strength (MOR) 15.75MPa, MOE 2905.34 and Internal Bond properties 0.5748MPa.Outcome of this proposed research will provided valuable databases to the wood based industry to use Kelampayan as an alternative raw material in their down streams production such as particleboard, medium-density board and chipboard manufacturing.


2017 ◽  
Vol 11 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Brundaban Patro ◽  
D. Shashidhar ◽  
B. Rajeshwer ◽  
Saroj Kumar Padhi

Background: Due to light weight, high performance and excellent mechanical properties, carbon fibers are considered a key material in the 21st century. These are extensively used in many industries for structural usages, such as aerospace, aeronautical, sporting goods applications, and automotive and medical devices, due to their desirable strength to weight properties. Now, these are globally accepted as a high performance and high-strength material. Most of the carbon fibers are derived from polyacrylonitrile fiber precursor. These materials have the potential for fire hazards caused due to heat, smoke, and electric short circuit. Objective: To prepare polyacrylonitrile carbon and epoxy resin laminates in multilayers by hand-lay-up method and testing by ASTM (American Society for Testing and Materials) standards. Method: Polyacrylonitrile carbon fiber/epoxy resin composites are prepared using the hand-lay-up method. For the non-destructive testing, the ultrasonic type is used. For the destructive testing, a universal testing machine is used to test the tensile test, the flexural test and the inter-laminar shear stress test, as per the ASTM standard. Subsequently, the physical properties, such as the density test and the fiber content, the resin content and the void content tests of the laminate are carried out. Results: The experimental results show that the matrix laminates have good mechanical and physical properties. Conclusion: Preparation and testing of polyacrylonitrile carbon/epoxy resin composites are carried out and the prepared laminates exhibit good mechanical and physical properties. Hence, the laminates can be used in many industrial and commercial applications, as a composite material.


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