scholarly journals Mechanical Properties of Laminated Veneer Lumber Beams Strengthened with CFRP Sheets

2019 ◽  
Vol 65 (2) ◽  
pp. 57-66 ◽  
Author(s):  
M. Bakalarz ◽  
P. G. Kossakowski
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Bending Strength ◽  
Carbon Fabric ◽  
Static Work ◽  
Work Analysis ◽  
Cfrp Sheets ◽  
Laminated Veneer Lumber ◽  
Frp Reinforcement ◽  
Bottom Face

AbstractThis paper presents the results of the static work analysis of laminated veneer lumber (LVL) beams strengthened with carbon fabric sheets (CFRP). Tested specimens were 45mm wide, 100 mm high, and 1700 mm long. Two types of strengthening arrangements were assumed as follows: 1. One layer of sheet bonded to the bottom face; 2. U-shape half-wrapped reinforcement; both sides wrapped to half of the height of the cross-section. The reinforcement ratios were 0.22% and 0.72%, respectively. In both cases, the FRP reinforcement was bonded along the entire span of the element by means of epoxy resin. The reinforcement of the elements resulted in an increase in the bending strength by 30% and 35%, respectively, as well as an increase in the global modulus of elasticity in bending greater than 20% for both configurations (in comparison to the reference elements).

The Modification of Mechanical Properties of Changbai Mountain Smell Pine Used by Floor

2012 ◽  
Vol 430-432 ◽  
pp. 866-868
Author(s):  
Xiao Yi Niu ◽  
Yu Wen Bai ◽  
Xue Wang
Keyword(s):  
Mechanical Properties ◽  
Optimum Condition ◽  
Small Molecules ◽  
Phenolic Resin ◽  
Bending Strength ◽  
Changbai Mountain ◽  
Molar Ratio ◽  
Absolute Pressure ◽  
Mass Ratio ◽  
Laminated Veneer Lumber

In this experiment, do smell pine impregnated pressure experiments with small molecules phenolic resin. Prepare different small molecules and phenolic resin by orthogonal.Handle the specimens. Compare the treated material with the smell pine. The optimum condition is the temperature of 60°C, PVA: P (mass ratio) = 3%, P: F: NaOH (molar ratio) = 1:1.2:0.3, the absolute pressure 2.5 Mpa, the temperature of 120 °C hot 15 minutes under the conditions. While smell pine laminated veneer lumber bending strength increased 67.53%.

Engineered Wood Composite of Laminated Veneer Lumber: Physical and Mechanical Properties

2016 ◽  
Vol 842 ◽  
pp. 103-128
Author(s):  
Kang Chiang Liew ◽  
Singan Grace
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
P Value ◽  
Thickness Swelling ◽  
Laminated Veneer Lumber ◽  
Physical Testing ◽  
Acacia Hybrid

Utilisation of forest plantation species such as Acacia hybrid has been used in wood-based industry as an alternative to solid wood that was usually attained from natural forest. While, the under-utilised species such as Mangifera sp. is not often been used as raw material for wood products, in this study, laminated veneer lumber (LVL) has been produced from Acacia hybrid and Mangifera sp. The physical and mechanical properties of LVL were determined and compared. For physical testing, the range value of moisture content was 9.41% to 14.56%, Density was 487.90 kg/m3 to 699.10 kg/m3, thickness swelling was between 0.20% to 6.05%, water absorption between 32.71% to 91.25%, and rate of delamination from 0% to 100%. Mangifera sp. LVL has higher moisture content, rate of delamination, and water absorbency. In mechanical testing, it is been found that Acacia hybrid LVL has overall higher strength compared to Mangifera sp. LVL, in terms of static bending strength (MOR and MOE), shear strength, and compression strength. Range of value for MOR was between 10.27 N/mm2 to 129.99 N/mm2, MOE between 1138 N/mm2 to 16472.93 N/mm2, shear strength between 0.43 N/mm2 to 3.40 N/mm2, and compression between 139.45 N/mm2 to 6749.74 N/mm2. For physical testing, the overall result of p-value for moisture content, water absorption, and delamination were significant at p ≤ 0.05, while density and thickness swelling were not significant at p ≥ 0.05. For overall result, the p-value for static bending strength (MOR and MOE) was significant at p ≤ 0.05 while for shear strength and compression strength were not significant at p ≥ 0.05.

scholarly journals Highly Mechanical Performance of Laminated Veneer Lumber Induced by High Voltage Electrostatic Field

2019 ◽  
pp. 67-75
Author(s):  
Qian He ◽  
Tianyi Zhan ◽  
Zehui Ju ◽  
Haiyang Zhang ◽  
Lu Hong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
High Voltage ◽  
Electrostatic Field ◽  
Shear Failure ◽  
Bending Strength ◽  
Mechanical Performance ◽  
Contact Angles ◽  
Bonding Interface ◽  
Laminated Veneer Lumber

The high voltage electrostatic field (HVEF), as a novel technology, was applied in the study to obtain a highly mechanical performance of LVL (laminated veneer lumber) by increasing limiting value of shear failure strength directly affected by bonding strength. The surface property of wood, polymerization extent of PF, bonding interface of wood-to-PF and mechanical properties of LVL were investigated under the HVEF treatment. The results showed that increased free radicals and total surface energy were acquired under the HVEF treatment resulting from more polar groups (?OH, ?CHO) and ions were triggered leading to decreased contact angles identified both for Poplar and Masson specimens. The HVEF provided more reactions among wood-to-UF and more cross linking reaction of PF occurred in the treating step. The tendency of vertical density profile was more extremely steep than the control with max density increased by 24.93% and 30.24% for Poplar and Masson LVL respectively since adhesive aggregated continuously and orderly along bonding interface and permeation depth reduced to around 200 ?m, accounting for improved bonding shear strength, which eventually brought an enhancement on mechanical properties of LVL with horizon shear strength (?and?), modulus of elasticity and static bending strength significantly enhanced by 14.65%, 10.68%, 20.67% and 12.34% for Poplar LVL and that of Masson LVL enhanced by 17.30%, 13.93%, 18.55% and 12.72%. Besides, the delamination ratio was decreased by 49.57% and 58.32% respectively both for Poplar and Masson specimens.

Modulus of Elasticity and Bending Strength of Squared Timber with Wane of Spruce and Larch

2013 ◽  
Vol 778 ◽  
pp. 369-376
Author(s):  
Thomas Schrentewein
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Effective Cross Section ◽  
Load Bearing ◽  
Fracture Tests ◽  
Wooden Structures ◽  
Bending Fracture ◽  
Southern European Countries

Historical wooden structures are made of round timber or frequently of squared timber with wane, in southern European countries also known as Uso Fiume and Uso Trieste. Knowledge of the mechanical properties of these load-bearing structures is very important in their assessment and maintenance. In two research projects undertaken in cooperation with IVALSA/CNR, TIS Techno Innovation South Tyrol, Microtec and Lignaconsult, more than 750 spruce and larch beams were subjected to bending fracture tests to determine their mechanical properties. Using existing datasets, a method was developed to determine the modulus of elasticity of an irregular cross section which varies along the length of the beam. If the effective cross-section geometry of a wooden structure made from squared timber with wane is known, the elasticity behaviour and the load-bearing capacity can be defined using the calculated mechanical properties.

Preparation of Sialon/Si3N4-SiC Composite Refractories Using Kyanite Tailings

2016 ◽  
Vol 697 ◽  
pp. 467-471 ◽  
Author(s):  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
Xin Min ◽  
Li Na Zhang
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Cross Section ◽  
Compression Strength ◽  
Carbothermal Reduction ◽  
Bending Strength ◽  
Synthesis Temperature ◽  
Composite Powders ◽  
Excess Carbon ◽  
Sic Composites

Sialon-SiC composite powders were synthesized from kyanite tailings through the carbothermal reduction nitridation (CRN) technique. Using Sialon-SiC composites to substitute Si3N4 composites via the CRN technique synthesize Sialon/Si3N4-SiC composite refractories. The phase composition, cross section morphology, and the substituent amount of Sialon-SiC composites impact on refractories mechanical properties were investigated, respectively. The optimized synthesis temperature for the CRN reaction was found to be 1550 °C for 4 h with the excess carbon 20%. The substituent amount of Sialon-SiC was 25%, the mechanical properties of Sialon/Si3N4-SiC composite refractories reached optimal performance, which bending strength value was 41.8 MPa and compression strength value was 61.6 MPa.

scholarly journals Flexural tests of masonry beam with and without reinforced bar

2019 ◽  
Vol 276 ◽  
pp. 01018
Author(s):  
Ida Ayu Made Budiwati ◽  
I Ketut Sudarsana
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Cross Section ◽  
Bending Strength ◽  
Wire Mesh ◽  
Steel Rebar ◽  
Reinforced Masonry ◽  
Flexural Tests

Behaviour of reinforced masonry has been studied experimentally to determine its strength potential. The increase in either compressive or tensile strength of masonry is possible due to the existence of rebar or wire mesh. The research is carried out to determine the effect of steel rebar on flexural strength of reinforced masonry beam using local brick. The square hollow masonry beams of 330x330mm with and without reinforced bar were tested in the laboratory to determine the load and deflection curves and bending strength. The rebar was located at the centre of beam’s cross section and left unbounded. Mechanical properties of masonry’s constitute were also determined. It was found that the flexural strength of beams with rebar of 22 mm diameter was greater 11 times than that of beam without rebar. However, that strength was only 1.6 times due to the weaker end connections of the beam to the rebar. Flexural strength of reinforced masonry beam with 22 mm rebar was greater 2.7 times compared to the beam using a rebar diameter of 16 mm.

The Optimum Design of Production Technology of the Poplar LVL

2009 ◽  
Vol 620-622 ◽  
pp. 141-144
Author(s):  
Li Zhang ◽  
Ying Cheng Hu ◽  
Peng Chen ◽  
Jian Peng Hu ◽  
Fei Pin Yuan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Optimum Design ◽  
Production Technology ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Design Method ◽  
Uniform Design ◽  
Laminated Veneer Lumber ◽  
Press Temperature ◽  
The Press

In this paper, the production technology of laminated veneer lumber was optimized by using the uniform design method. The effects of production technology, such as the press duration, the press temperature, the press pressure and the adhesive spread, were found statistically significant on some mechanical properties of LVL. So in this paper, the thickness of LVL board was a fixed value, but the press duration, the press temperature and the adhesive spread were variable. The modulus of elasticity (MOE) and static bending strength (MOR) as predicted by the ANN approach and the regression functions were compared with the experimental values. It was shown that the proposed neural network model was able to predict valuable mechanical properties, such as the modulus of elasticity and static bending strength, that would facilitate the development of optimum design of properties for manufacturing high quality materials.

Effect of Epoxy Resin Concentration on Some Mechanical Properties of Carbon Fabric/ Nitrile Rubber Reinforced Composites

2019 ◽  
Vol 9 (1) ◽  
pp. 1-15
Author(s):  
Sawsan Fakhry Halim ◽  
Said Sayed Gad El Kholy ◽  
HalaFikry Naguib ◽  
Riham Samir Hegazy ◽  
Nermen Mohamed Baheg
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Nitrile Rubber ◽  
Reinforced Composites ◽  
Carbon Fabric

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

scholarly journals Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 220
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
George I. Mantanis
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
High Density ◽  
Thickness Swelling ◽  
Formaldehyde Content ◽  
Uf Resin ◽  
Natural Wood ◽  
European Standards

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

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