Evaluation of the Moisture Content in Stiffness Properties of Structural Glulam Beams

2015 ◽  
Vol 1088 ◽  
pp. 676-679 ◽  
Author(s):  
Francisco Antonio Rocco Lahr ◽  
André Luis Christoforo ◽  
Cristiane Inácio de Campos ◽  
Elen Aparecida Martines Morales ◽  
Juliana Cortez Barbosa ◽  
...  
Keyword(s):  
Significant Influence ◽  
Modulus Of Elasticity ◽  
Compaction Pressure ◽  
Storage Period ◽  
Pinus Elliottii ◽  
Bending Test ◽  
Test Procedures ◽  
Transversal Vibration ◽  
Stiffness Properties ◽  
Glued Laminated Timber

This research aimed to evaluate the influence of storage time (0, 96 hours) ofPinus elliottiipieces and the tests to obtaining modulus of elasticity (static bending and transversal vibration) in glued laminated timber beams, produced with resorcinol based adhesive and 0.8 MPa compaction pressure. After pieces were properly prepared, part of them was used in immediate three manufacturing glulam beams, tested after adhesive cure, and part stored for 96 hours under a roof with a temperature of 25°C and relative humidity of 60% for subsequent manufacturing and testing three other glulam beams. Results of analysis of variance (ANOVA) revealed that the storage period was significant influence in modulus of elasticity obtained in static bending test (8% reduction from 0 to 96 hours). This not occurred with modulus of elasticity obtained by transversal vibration test (no significant influence). ANOVA results showed equivalence of means in both test procedures.

Influence of Storage Period of Pieces in Stiffness of Pinus elliottii Glulam Beams

2014 ◽  
Vol 1025-1026 ◽  
pp. 64-67 ◽  
Author(s):  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Eduardo Chahud ◽  
Luiz A. Melgaço N. Branco ◽  
Rosane A.G. Battistelle ◽  
...  
Keyword(s):  
Significant Influence ◽  
Modulus Of Elasticity ◽  
Compaction Pressure ◽  
Storage Period ◽  
Pinus Elliottii ◽  
Storage Conditions ◽  
Bending Test ◽  
Test Procedures ◽  
Transversal Vibration ◽  
Glued Laminated Timber

This study aimed to investigate the influence of storage time (0, 48 hours) of Pinus elliottii pieces and the tests to obtaining modulus of elasticity (static bending and transversal vibration) in glued laminated timber beams, produced with resorcinol based adhesive and 0.8 MPa compaction pressure. After pieces were properly prepared, part of them was used in immediate three manufacturing glulam beams, tested after adhesive cure, and part stored for 48 hours under a roof with a temperature of 25°C and relative humidity of 60% for subsequent manufacturing and testing three other glulam beams. Results of analysis of variance (ANOVA) revealed that the storage period was significant influence in modulus of elasticity obtained in static bending test (8% reduction from 0 to 48 hours). This not occurred with modulus of elasticity obtained by transversal vibration test (no significant influence). ANOVA results showed equivalence of means in both test procedures. New researches ire needed to better understand the investigated phenomenon, using new wood species, other storage conditions and a great number of samples.

scholarly journals The Usefulness of Pine Timber (Pinus sylvestris L.) for the Production of Structural Elements. Part II: Strength Properties of Glued Laminated Timber

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4029
Author(s):  
Radosław Mirski ◽  
Dorota Dziurka ◽  
Monika Chuda-Kowalska ◽  
Jakub Kawalerczyk ◽  
Marcin Kuliński ◽  
...  
Keyword(s):  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Strength Properties ◽  
Bending Test ◽  
Structural Elements ◽  
Pine Wood ◽  
Glued Laminated Timber ◽  
The Individual ◽  
Horizontal Arrangement

The paper assessed the feasibility of manufacturing glued structural elements made of pine wood after grading it mechanically in a horizontal arrangement. It was assumed that the pine wood was not free of defects and that the outer lamellas would also be visually inspected. This would result in only rejecting items with large, rotten knots. Beams of the assumed grades GL32c, GL28c and GL24c were made of the examined pine wood. Our study indicated that the expected modulus of elasticity in bending was largely maintained by the designed beam models but that their strength was connected with the quality of the respective lamellas, rather than with their modulus of elasticity. On average, the bending strength of the beams was 44.6 MPa. The cause of their destruction was the individual technical quality of a given item of timber, which was loosely related to its modulus of elasticity, assessed in a bending test. Although the modulus of elasticity of the manufactured beam types differed quite significantly (11.45–14.08 kN/mm2), the bending strength for all types was similar. Significant differences occurred only during a more detailed analysis because lower classes were characterized by a greater variation of the bending strength. In this case, beams with a strength of 24 MPa to 50 MPa appeared.

scholarly journals SCARF JOINTS IN GLUED LAMINATED TIMBER OF PARICÁ

FLORESTA ◽  
2021 ◽  
Vol 51 (3) ◽  
pp. 713
Author(s):  
Rodrigo Figueiredo Terezo ◽  
Talitha Oliveira Rosa ◽  
Francisco Raphael Cabral Furtado ◽  
Camilla Gabriela Melo Ampessan ◽  
Alexsandro Bayestorff Cunha ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
Visual Inspection ◽  
Strength Test ◽  
Bending Test ◽  
Tensile Strength Test ◽  
Glued Laminated Timber ◽  
Schizolobium Parahyba ◽  
Scarf Joint ◽  
Scarf Joints

Glued Laminated Timber (GLULAM) is manufactured by joining wood lamellae glued in parallel to each other. GLULAM with larger longitudinal dimensions can be obtained by gluing the tops of two wood lamellae. The gluing of the tops can be done using wedge-shaped scarf joints. However, the joints produce a discontinuity in the wood, being areas considered as susceptible to rupture. In this way, the objectives were to evaluate four slopes (1:6; 1:8; 1:10 and 1:12) in scarf joints of Schizolobium parahyba var. amazonicum timber for use with structural purposes; and glued laminated timber beams – GLULAM manufactured with the scarf joint with the best performance by the modulus of elasticity – MOE (theoretical and analytical MOE values). Each laminated timber used to produce the test specimens was classified by visual inspection that aimed at the absence of defects, such as knots. The test specimens were adapted to the four-point static bending test and to the tensile strength test in parallel to the grain direction, in accordance to the NBR 7190 (1997). The slope of 1:12 showed the best results, while the slope of 1:6 presented the lowest results when compared with the control. The beams of 5 x 9.5 x 220 cm, composed of joints with slopes of 1:12, showed MOE values statistically equal to those of beams without joints. The scarf joint proved to be an alternative for use in glulam beams of paricá, as it presents stiffness and strength comparable with those of beams without a joint.

scholarly journals Number of laminae on the mechanical behavior of glued laminated timber (glulam) of Toona ciliata produced with vegetable polyurethane adhesive

2019 ◽  
Vol 43 ◽  
Author(s):  
Douglas Lamounier Faria ◽  
Thiago Moreira Cruz ◽  
Laércio Mesquita Júnior ◽  
Paulo Junio Duarte ◽  
Lourival Marin Mendes ◽  
...  
Keyword(s):  
Shear Strength ◽  
Mechanical Behavior ◽  
Modulus Of Elasticity ◽  
Chemical Characterization ◽  
Solid Wood ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Polyurethane Adhesive ◽  
Glued Laminated Timber ◽  
Toona Ciliata

ABSTRACT The glued laminated timber (glulam) is a composite material obtained from the bonding of wood laminae arranged with parallel fibers put together. The purpose of this paper was to evaluate the influence of the number of laminae on the mechanical behavior of glulam of Toona ciliata produced with vegetable-based polyurethane adhesive. The glulam beams were produced with lamellae in the dimensions of 6.0 x 1.5 x 120.0 cm, with 3 beams being made per treatment, which were structurally composed by 5, 7 and 9 laminae. The polyurethane adhesive based on castor oil was used, applying a grammage of 350 g m-². For the technological characterization of the wood the moisture in the dry base, bulk density, chemical characterization, compressive strength parallel to the fibers, shear and modulus of elasticity (MOE) and rupture (MOR) in the static bending test. While the properties of modulus of elasticity (MOE), modulus of rupture (MOR), shear strength, delamination and visualization of the glue line through photomicrographs of the laminated wood samples were determined for glulam beams. The results showed that the beams with 5 laminae presented values similar to solid wood. The increase in the number of laminae provided lower values for stiffness and strength of the beams. The photomicrographs showed the quality of the bonding and the satisfactory values for shear strength and delamination, indicating the viability of the species under study for situations with high moisture content.

High Temperature Storage and Gamma Radiation Effects on Mechanical Properties of Stacked Die Package

2014 ◽  
Vol 895 ◽  
pp. 567-570
Author(s):  
Azman Jalar ◽  
Wan Yusmawati Wan Yusoff ◽  
Norinsan Kamil Othman ◽  
Irman Abdul Rahman
Keyword(s):  
High Temperature ◽  
Gamma Radiation ◽  
Radiation Effects ◽  
Storage Period ◽  
Bending Test ◽  
Three Point Bending ◽  
Micromechanical Properties ◽  
3D Ct Scan ◽  
High Temperature Storage ◽  
Temperature Storage

Effect of gamma radiation (1.33 MeV) and high temperature storage of semiconductor package towards micromechanical properties has been investigated. The in-house fabricated Quad Flat No Lead was exposed to gamma radiation with the dose of 5 Gy. Afterwards, high temperature storage was performed at 150 °C for 10, 100 and 1000 hours. Subsequently, the three point bending technique was carried out to obtain the micromechanical properties of semiconductor package. The fracture of the packages caused by three point bending test was subjected to 3D CT scan to capture the image of the fracture. Irradiated package shows the decreasing in their strength with increasing doses of gamma radiation. However, the strength of the package was improved after high temperature storage for 10 hours and decreased as the storage period is extended. Further analysis exhibited that high temperature storage for 10 hours is reveal as good thermal treatment for package in radioactive environment application.

Study on Application of Stress Wave for Nondestructive Test of Wood Defects

2013 ◽  
Vol 401-403 ◽  
pp. 1119-1123 ◽  
Author(s):  
Wen Shu Lin ◽  
Jin Zhuo Wu
Keyword(s):  
Nondestructive Test ◽  
Stress Wave ◽  
Significant Influence ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Wood Products ◽  
Propagation Time ◽  
Propagation Parameters ◽  
Wave Technique ◽  
Wooden Structures

The elm wood samples were tested by the technique of stress wave, and the testing results were analyzed by using the statistic software of SPSS. The results showed that the moister content of wood, wood crack, the sizes of holes and numbers of holes have significant influence on propagation parameters and dynamic modulus of elasticity. Under the same specifications, the propagation time of the stress wave was longer in the wood with holes or cracks than the perfect wood samples, and the time become longer with the increasing the sizes and numbers of holes or cracks. The studying results of the thesis will provide a sound background for the application of stress-wave technique in detecting the inner defects of wood products and other wooden structures.

scholarly journals Influence of Leather Fiber on Modulus of Elasticity in Bending Test and of Bend Strength of Particleboards

2021 ◽  
Vol 24 (suppl 2) ◽  
Author(s):  
Renato Cardoso de Oliveira ◽  
Rodrigo Andraus Bispo ◽  
Mariana Ferreira Trevisan ◽  
Caroline Graminha Gilio ◽  
Felipe Reis Rodrigues ◽  
...  
Keyword(s):  
Modulus Of Elasticity ◽  
Bending Test ◽  
Bend Strength

Effects of Impurity Elements on Green Strength of Powder Compacts

2010 ◽  
Vol 654-656 ◽  
pp. 811-814 ◽  
Author(s):  
Ju Beom Lim ◽  
Colleen J. Bettles ◽  
Barry C. Muddle ◽  
Nho Kwang Park
Keyword(s):  
Surface Deformation ◽  
Surface Condition ◽  
Compaction Pressure ◽  
Bending Test ◽  
Solid Solution Strengthening ◽  
Green Strength ◽  
Metallic Compounds ◽  
Powder Particles ◽  
Indirect Tensile ◽  
Powder Compacts

The green strength of a powder compact results from the mechanical interlocking of the irregularities on the particle surfaces. During compaction, particle rearrangement, plastic deformation and particularly surface deformation of powders occur. Titanium powder is susceptible to interstitial element contamination, which may lead to solid solution strengthening of the particles and/or the formation of non-metallic compounds on the surface. However, the influence of these various impurities, namely oxygen and nitrogen, on the green strength has not been investigated. This work investigates and quantitatively evaluates the factors influencing the green strength of the powder compacts. The indirect tensile test was applied for the determination of the green strength of the powder compacts, and test results were compared to that of a more conventional 3-point bending test. The substantial dependence of green strength on both the amount of impurity element in the core of the powder particles and the compaction pressure is demonstrated. The effect of the surface condition of the powder particles on green strength is also reported.

scholarly journals Effect of introduction of fullerene soot on mechanical properties of unidirectional thermoplastic tape

2018 ◽  
Vol 245 ◽  
pp. 04011 ◽  
Author(s):  
Ilya Kobykhno ◽  
Dmytro Honcharenko ◽  
Vladimir Yadykin ◽  
Oleg Stolyarov ◽  
Oleg Tolochko
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Carbon Fibers ◽  
Modulus Of Elasticity ◽  
Hot Pressing ◽  
Bending Test ◽  
Transverse Reinforcement ◽  
Fullerene Soot

A series of unidirectional thermoplastic tapes (UD tapes) specimens based on carbon fibers and polyamide filled with fullerene soot in a concentration of up to 4 wt. % was made. From the obtained tapes by the method of hot pressing, composite materials (CM) specimens with 0/0 and 90/90 ply orientations were made. A study of the mechanical properties of the samples obtained by the 3-point bending test was made. Shown that the introduction of fullerene soot up to 2 wt. % can significantly increase the strength and modulus of elasticity of both longitudinal and transverse reinforcement directions. Further increase in the concentration of soot leads to a decrease in properties. A theory that describes the effect of fullerene soot on the properties of CM, including the increase and further decrease in properties, depending on the concentration of nanoparticles was proposed.

Genotypic variation in the basic density, dynamic modulus of elasticity and tracheid traits of Pinus elliottii in three progeny trials in southern China

Holzforschung ◽  
2019 ◽  
Vol 74 (1) ◽  
pp. 1-9
Author(s):  
Meng Lai ◽  
Leiming Dong ◽  
Chunhui Leng ◽  
Lu Zhang ◽  
Min Yi
Keyword(s):  
Genetic Correlation ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Southern China ◽  
Wood Quality ◽  
Basic Density ◽  
Pinus Elliottii ◽  
Wood Properties ◽  
Correlated Response ◽  
Dynamic Modulus Of Elasticity

AbstractA firm understanding of the genetic relationships among wood properties is a prerequisite for breeding for higher wood quality in Pinus elliottii families. To examine and deal with such relationships, increment cores were sampled at breast height from 1260 trees in 42 open-pollinated families in three 27-year-old Slash pine progeny trials in southern China, and genetic variation, genotype-by-environment (G × E) interaction, genetic correlation and correlated response were investigated. The basic density (BD), dynamic modulus of elasticity (MOED) and tracheid traits were found to be under moderate to strong genetic control for the three locations combined, with individual narrow-sense and family mean heritability ranging from 0.28 to 0.44 and 0.52 to 0.69, respectively. Type B genetic correlation estimates indicated that the G × E interaction had a small-level influence on wood properties. Strong genetic correlations (rg) were found between BD and MOED at the three sites (rg = 0.46–0.85), and BD or MOED showed moderate to strong correlations with most tracheid traits at specific localities. In tree breeding programs, one possible strategy would be to improve pulpwood quality and the strength of structural wood through selection for different wood quality traits.

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