Relationships between mechanical properties of oak timber (Quercus robur L.)

Holzforschung ◽  
2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Guillermo Riesco Muñoz ◽  
Andrés Remacha Gete
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Prediction Models ◽  
Mechanical Tests ◽  
Clear Wood ◽  
Oak Trees ◽  
Impact Bending ◽  
Strength And Stiffness ◽  
Selection Of

Abstract Ring-porous hardwoods such as oak are in high demand for furniture-making, cooperage, flooring, and construction. However, evaluating the quality of such timber is difficult and time consuming, and simpler tests are required. Models for predicting as many mechanical properties as possible, based on easier-to-determine mechanical tests, may help. In this study, the hardness, modulus of elasticity, bending, compression, and impact bending strength parallel to grain were tested on defect-free laths obtained from a sample of 42 oak trees. The relationships between the variables were investigated. Three models that relate the resistance to axial compression with bending strength and stiffness (R2>0.55; P<0.01) are proposed for defect-free oak timber. Selection of models mainly depended on the bias, which was highly variable among the models tested. The prediction models proposed in the international standard EN 384:2004 for structural dimension timber are not suitable for small clear wood specimens, especially in very elastic woods. The relative independence of hardness and impact bending strength as regards the other mechanical properties is also demonstrated.

scholarly journals Analisis Sifat Mekanik Hasil Pengelasan SMAW dengan Akar Las Tig dan Las SMAW pada Pipa API 5L

2019 ◽  
Vol 17 (1) ◽  
pp. 37
Author(s):  
Muas M ◽  
Muhammad Arsyad Suyuti ◽  
Rasul Rasul ◽  
Patta Hajji
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bending Strength ◽  
Mechanical Tests ◽  
Current Variation ◽  
Root Face ◽  
A Current ◽  
Root Methods ◽  
Made In

The purpose of this research is to know the mechanical properties of the welds due to the current variation of welding joint API 5L using TIG and SMAW welding root methods. Preparation of specimens of pipe API 5L PSL1 grade X56 (Ø 177.8 mm, length 200 mm, width 7 mm), then specimens preparation were made in a single V 600, root gap 2mm, root face 2mm. Filling the welding roots with TIG welding and SMAW using electrodes E7018 with a current variation 70A, 80A, 90A. Mechanical tests consist of tensile, bending and hard test. The results showed that the quality of a good TIG root weld at 70A, the highest tensile strength of the weld joint 52.27 kgf/mm2 (70A), the highest hardnest 164,217 HRB (90A), the bending strength 1.123,061 N/mm2 (70A) using face bend method and 1,172,959 N/mm2 with root bend. In SMAW root welding, the highest tensile strength 54.27 kgf/mm2 (70 A) , the highest hardnest  158.717 HRB (70 A), the highest bending strength 1.115,611 N/mm2 (70 A) using face bend method, and 1.161,748 N/ mm2 with root bend. 

scholarly journals Effect of Post-Process Curing and Washing Time on Mechanical Properties of mSLA Printouts

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4856
Author(s):  
Bartłomiej Nowacki ◽  
Paweł Kowol ◽  
Mateusz Kozioł ◽  
Piotr Olesik ◽  
Jakub Wieczorek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Curing Time ◽  
Cross Sectional ◽  
Post Process ◽  
Order Of Magnitude ◽  
Static Tensile ◽  
High Roughness ◽  
Ambiguous Effect

The article discusses the influence of the post-process on the mechanical properties of elements produced with the use of the mask stereolithography (mSLA) method. Printed samples were subjected to the following post-process steps: Washing and post-curing, at various times. Then, static tensile and static bending tests were carried out, as well as Shore D hardness measurements for the inner and surface part of the sample, as well as profilographometric analysis of the surface. The post-curing time has been found to strongly affect the tensile and bending strength of printouts, and to improve their surface quality. Washing has an ambiguous effect on the strength of the printouts, but, in the end, it was found that extended washing slightly reduces the strength. Washing significantly affects the quality of the printout surface. A washing time that is too short results in a surface that strongly resembles the printing process, with high roughness. Increasing the washing time to 10 min lowers the roughness by one order of magnitude. Post-curing has also been shown to be beneficial for the cured sample with the application of shielding water. This approach results in an improvement in the flexural strength of the printouts. In general, the obtained research results indicate that, for printouts with cross-sectional dimensions of several mm, the optimal washing time is no more than 10 min and the post-curing time is at least 30 min.

scholarly journals The Effect of Borax Solution as Preservative to the Mechanical Properties of Bamboo

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
M.A.P Handana ◽  
◽  
Besman Surbakti ◽  
Rahmi Karolina ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Bending Strength ◽  
Environmentally Friendly ◽  
Preservative Solution ◽  
Borax Solution ◽  
Preservative Solutions

The use of borax solution as a preservative in wood and bamboo materials is well known in the community. A borax solution is an environmentally friendly liquid that can dissolve in water, so it is suitable to be used as a preservative within cold or hot soaking techniques. The ability of borax to resist insects and fungus attacks on bamboo has been proven, but the effect of the solution on the strength of bamboo must also be investigated. This study conducts to investigate the effects of borax and its additives as preservative solutions to the mechanical properties of bamboos. The bamboos preservations were conducted by cold conditions of immersion, while the mechanical properties were performed to understand the effects of preservatives. The result of this study indicated that 30% to 50% borax in the preservative solution is sufficient to provide significant increase in strength for compressive strength, tensile strength, and bending strength of bamboo specimen. From this study, the use of borax solution in preserving the bamboos materials improved the quality of bamboos based on its mechanical properties.

Grade yields and wood properties of Norway spruce [Picea abies (L.) Karst.] from the Maritimes

1995 ◽  
Vol 71 (4) ◽  
pp. 473-478
Author(s):  
Y. H. Chui
Keyword(s):  
Mechanical Properties ◽  
Picea Abies ◽  
Norway Spruce ◽  
Wood Quality ◽  
Wood Properties ◽  
Bending Properties ◽  
Clear Wood ◽  
Comparative Information ◽  
Grade Yield

Norway spruce [Picea abies (L.) Karst.] is one of the major non-native softwood species in the Maritimes. A project was undertaken to evaluate the grade yields and mechanical properties of Norway spruce. The project also provided comparative information on the wood quality of two Norway spruce provenances from Germany and Poland. Four plantations were selected for the study with two of these plantations containing trees of known provenances. One plantation was mature and the other three were juvenile. In total, 530 pieces of lumber and the same number of matched small clear specimens were tested for bending properties. Prior to testing, the lumber was visually graded according to both British and Canadian specifications. Quality of lumber varied significantly between sites. Lumber from the Polish provenance had slightly better mechanical properties than that from trees of the German provenance. Compared with published information, the plantation-grown Norway spruce had lower clear wood bending properties and specific gravity than primary eastern Canadian spruce species and balsam fir, and natural Norway spruce grown in Europe. Key words: Norway spruce [Picea abies (L.) Karst.], wood quality, bending properties, grade yield

scholarly journals Influence of Site Conditions and Quality of Birch Wood on Its Properties and Utilization after Heat Treatment. Part I—Elastic and Strength Properties, Relationship to Water and Dimensional Stability

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 189 ◽  
Author(s):  
Vlastimil Borůvka ◽  
Roman Dudík ◽  
Aleš Zeidler ◽  
Tomáš Holeček
Keyword(s):  
Heat Treatment ◽  
Dimensional Stability ◽  
Bending Strength ◽  
Color Change ◽  
Untreated Wood ◽  
Strength Properties ◽  
Treatment Temperature ◽  
Impact Bending ◽  
The Impact

This work deals with the quality of birch (Betula pendula) wood from different sites and the impact of heat treatment on it. Two degrees of heat treatment were used, 170 °C and 190 °C. The resulting property values were compared with reference to untreated wood samples. These values were wood density, compressive strength, modulus of elasticity (MOE), bending strength (MOR), impact bending strength (toughness), hardness, swelling, limit of hygroscopicity, moisture content and color change. It was supposed that an increase in heat-treatment temperature could reduce strength properties and, adversely, lead to better shape and dimensional stability, which was confirmed by experiments. It was also shown that the properties of the wood before treatment affected their condition after heat treatment, and that the characteristic values and variability of birch properties from 4 sites, 8 stems totally, were reflected in the properties of the heat-treated wood. Values of static MOR were the exception, where the quality of the input wood was less significant at a higher temperature, and this was even more significant in impact bending strength, where it manifested at a lower temperature degree. Impact bending strength also proved to be significantly negatively affected by heat treatment, about 48% at 170 °C, and up to 67% at 190 °C. On the contrary, the most positive results were the MOE and hardness increases at 170 °C by about 30% and about 21%, respectively, with a decrease in swelling at 190 °C by about 31%. On the basis of color change and other ascertained properties, there is a possibility that, after suitable heat treatment, birch could replace other woods (e.g., beech) for certain specific purposes, particularly in the furniture industry.

Determination of some Mechanical Characteristics of Wood Elements Improved with Composites Materials

2014 ◽  
Vol 1036 ◽  
pp. 30-35
Author(s):  
Aurora Cătălina Ianăşi
Keyword(s):  
Building Materials ◽  
Bending Strength ◽  
Testing Machine ◽  
Mechanical Tests ◽  
Accurate Analysis ◽  
Composites Materials ◽  
Reinforced Beams ◽  
Wood Beams ◽  
Mechanical Performances ◽  
Selection Of

Wood is a material of construction relatively inexpensive and easy to put into practice because of its lightness, reusability, simplicity in fabrication and environmental compatibility. However, its ability to lift load small compared to other building materials, it greatly limits the range of its use. Increasing the mechanical strength of wood elements used in construction is a goal that, once achieved, would expand the use of this material, with notable economic repercussions. The use of composite materials such as CFRP (carbon fiber reinforced plastic) as reinforcement for wood elements under bending loads like beams requires attention to the techniques of reinforcing for different layouts of CFRP elements. Each choice of reinforcing could potentially lead to different results. When the choice has been made, the next step is the selection of the most adequate CFRP elements. For this reason, selection of the reinforcement layout and material should be guided by an accurate analysis of the characteristics of the element to be reinforced in order to avoid ineffective interventions. The present paper is concerned with determination the performances of wood beams reinforced with CFRP composites by investigating their bending resistance and showing crushing damage in the bending region. All tested wood beamspresented in this paper were made from beech. The results for the un-reinforced beams are reported solely for the purpose of quantitatively evaluating the effectiveness of the interventions through a comparison with the results for CFRP strengthened beams. The technology of composite material reinforcement is based on using CFRP plates bonded with an epoxy resin on the wood beams. After bonding, the beams were tested to bending on a universal testing machine with a punctuated force placed at the middle of the beams. The results indicate that the behavior of reinforced beams with CFRP is totally different from that of un-reinforced one. During the performed tests, observations of the experimental loaddisplacement relationships showed that bending strength increased for wood beams reinforced with CFRP compared to those without CFRP reinforcement. Mechanical tests on the reinforced wood beams proved that CFRP materials produced flexural displacement and lifting increases of the beams that entitles us to say this kind of materials have improved the mechanical performances of tested wooden beams.

Method of Testing the Mechanical Properties of Vulcanizates Prepared from Latex as a Starting Material

1948 ◽  
Vol 21 (1) ◽  
pp. 168-179
Author(s):  
Marcel Pirot
Keyword(s):  
Mechanical Properties ◽  
Starting Material ◽  
Daily Production ◽  
Selection Of

Abstract With the method which has been described, it is possible to obtain reproducible results easily. It is hoped that the method will make it easier to study the properties of rubber mixtures prepared from latex. Furthermore the quantity of a latex mixture needed for such a test is small, i.e., of the order of 400 cc., so the method is particularly well adapted to the selection of Hevea trees on a basis of the quality of their latex. As a matter of fact, it will be easy in many cases to follow the collection of latex from a limited number of trees. It should even be possible, by using a single dipping form and reducing the size of the dipping tank, to follow the quality of the latex from the daily production of one tree, a procedure which is impossible with coagulated rubber.

scholarly journals Mechanical Properties of GFR & Graphite Epoxy Polymer Composites

2020 ◽  
Vol 5 (6) ◽  
pp. 560-565
Author(s):  
A. Aakash ◽  
S. Selvaraj
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Polymer Composite ◽  
Epoxy Polymer ◽  
Significant Degree ◽  
Polymer Composite Material ◽  
Water Ingestion ◽  
Selection Of

Composite materials have the great potential and widely used as building material in numerous applications. Polymer composite material obtains the necessary properties in a controlled significant degree by the selection of strands and lattice. The properties of the materials have been selected by choosing the correct proportion of matrix and reinforcements. To build the quality of the material by expanding the fiber substance of the material. In this current examination, the mechanical properties of the glass fiber and graphite is strengthened with epoxy polymer composite were considered. Here the open embellishment method was received for the manufacture of the polymer composite The mechanical properties, for example, rigidity, compression quality, sway quality and water ingestion test was resolved according to the ASTM norms. The mechanical properties were improved as the filaments support content expanded in the grid material.

Physical and Mechanical Properties of Hard Maple (Acer saccharum) and Yellow Poplar (Liriodendron tulipifera)

2020 ◽  
Vol 70 (3) ◽  
pp. 326-334
Author(s):  
Marly Gabriela Carmona Uzcategui ◽  
Roy Daniel Seale ◽  
Frederico José Nistal França
Keyword(s):  
United States ◽  
Mechanical Properties ◽  
Specific Gravity ◽  
Acer Saccharum ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Liriodendron Tulipifera ◽  
Eastern United States ◽  
Yellow Poplar ◽  
Clear Wood

Abstract Maple and poplar are common names of species that grow in the eastern United States. Physical and mechanical properties were evaluated from small clear wood specimens of hard maple (Acer saccharum) and yellow poplar (Liriodendron tulipifera). Specific gravity, static bending strength and modulus of elasticity, compression parallel and perpendicular to grain, and Janka hardness were tested. The experiments were carried out on defect-free specimens extracted from boards supplied by members of the Staircase Manufacturers Association. The material was donated by companies located in the eastern United States. On the basis of the findings, it can be stated that mechanical properties for maple and yellow poplar have not changed substantially because the average values remain in a range that is very close to the values published in previous studies.

scholarly journals Near infrared spectroscopy for assessing mechanical properties of Castanea sativa wood samples

2019 ◽  
Vol 50 (4) ◽  
pp. 191-197 ◽  
Author(s):  
Manuela Mancini ◽  
Elena Leoni ◽  
Michela Nocetti ◽  
Carlo Urbinati ◽  
Daniele Duca ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Bending Strength ◽  
Prediction Models ◽  
Castanea Sativa ◽  
Modulus Of Rupture ◽  
Current Standard ◽  
Standard Samples

Near infrared spectroscopy (NIR) is a technique widely used for the prediction of different chemical-physical features of wood. In this study, the technique was used to assess its potential to predict the mechanical characteristics of wood. Castanea sativa samples of three different European provenances were collected and laboratory tests were performed to assess the mechanical properties of wood samples. Modulus of elasticity (MOE), load-deflection curve and modulus of rupture (MOR) were calculated by using INSTRON machine with three points bending strength with elastic modulus, while density (D) was calculated according to the current standard. Samples were then analysed by means of NIR spectroscopy. The raw spectra were pre-processed and regression models were developed. Variables selection techniques were used to improve the model performance. In detail, MOE regression model returned an error of 696.01 MPa (R2=0.78). Instead, MOR and D prediction models must be further investigated on a wider number of samples considering the high variability in physical characteristics of chestnut wood. The results demonstrated the possibility to use NIR technique for the prediction of the mechanical properties of wood providing useful indications in evaluation-screening processes. Indeed, the presence of the principal wood compounds (cellulose, hemicellulose and lignin) and their influence in the characterisation of mechanical stress reactions were confirmed.

Sign in / Sign up

Export Citation Format

Share Document