Articoli di riviste: "Wood displacement"

1

Kajikawa, Shohei, Takashi Iizuka e Keisuke Yamaishi. "Displacement Behavior of Wood in Boss Forming Using Open-Die Wood Forging". Key Engineering Materials 504-506 (febbraio 2012): 1261–66. http://dx.doi.org/10.4028/www.scientific.net/kem.504-506.1261.

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Biomass materials such as wood are attracting renewed attention as alternative fuels in order to help resolve environmental resources caused by the use of fossil fuels. In this study, the possibility of products being processed from wood bulk was investigated by means of boss forming using open-die forging. Additionally, the difference in formability and deformation behavior during forging was investigated by changing the experimental conditions, such as the moisture content of the wood billets used, the forming pressure, and the forming temperature. The experimental results showed that wood had enough liquidity to be forged, and that two sudden and large increases in displacement occur during forging. Finally, the conditions governing these displacements were summarized from these results

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Zemljic, Borut. "Abomasal displacement in cattle". Veterinarski glasnik 57, n. 5-6 (2003): 335–48. http://dx.doi.org/10.2298/vetgl0306335z.

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Left abomasal displacement can be treated among other techniques also with the rolling technique accompanied with a percutaneus paramedian abomasopexy using toggle pin fixators of cornel wood. This method is reliable, quick and cheap.

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Pereira, Rodrigo Allan, Francisco Carlos Gomes, Roberto Alves Braga Júnior e Fernando Pujaico Rivera. "DISPLACEMENT MEASUREMENT IN SAWN WOOD AND WOOD PANEL BEAMS USING PARTICLE IMAGE VELOCIMETRY". CERNE 25, n. 1 (marzo 2019): 110–18. http://dx.doi.org/10.1590/01047760201925012619.

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Jones, Michael T., e Paul R. Sievert. "Effects of Stochastic Flood Disturbance on Adult Wood Turtles, Glyptemys insculpta, in Massachusetts". Canadian Field-Naturalist 123, n. 4 (1 ottobre 2009): 313. http://dx.doi.org/10.22621/cfn.v123i4.1000.

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The homing ability of non-marine turtles has been studied in a variety of taxa, and many species appear to be capable of short-range homing on the scale of several hundred meters or a few kilometers following experimental displacement. However, the behavioral response of turtles following a naturally caused displacement has seldom been reported. In this paper, we describe the effect of displacement ranging from 1.4 to 16.8 km (average = 4.8 km) by severe floods in a stream system in Massachusetts. We radio-tracked 38 adult Wood Turtles (Glyptemys insculpta) at five separate sites in Franklin County, Massachusetts, for periods ranging from one to four activity seasons and documented the displacement of a total of 12 Wood Turtles during seven floods between 2004 and 2008. Based on the average rate of displacement per flood and annual flood frequency, we estimate that, during our study, floods displaced over 40% of this Wood Turtle subpopulation annually. We present evidence that displacement results in elevated mortality rates and that displaced Wood Turtles mate and nest in the year following displacement at rates well below average; on a longer time scale, however, displacement by flooding may be an important mechanism of population connectivity in some areas. We also present evidence that most Wood Turtles avoid stream segments with stream gradient steeper than 1%; this may in part reflect an adaptation to avoid severe floods. Regional models and empirical data from stream gages suggest that flood intensity may currently be on an increasing trend. Conversion of upland from forest and fields to impervious surfaces and hardening of upstream riverbanks may have exacerbated recent flooding and decreased the resiliency of the riparian system to increased precipitation.

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Lee, M. C., Y. L. Tsai, R. Z. Wang e M. L. Lin. "Finding the displacement of wood structure in heritage building by 3D laser scanner". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences II-5/W3 (11 agosto 2015): 165–69. http://dx.doi.org/10.5194/isprsannals-ii-5-w3-165-2015.

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Heritage buildings are highly prone to long term damage from the microclimate, scourge and vandalism, which can result in damaged materials, structures, painting and cultural heritage items. This study will focus on finding the displacement of wood structural members through the use of a 3D laser scanner and the 4D concept of time. The results will compare the scans from different periods to find the difference (if any) in the structural member position. Wood structures usually consist of numerous wood members connected to form the structure. However, these members can be damaged in various ways such as physical mechanisms, chemical reactions, and biological corrosion. When damage to the wood structure occurs, the structural displacement can be affected, and if affected severely, can lead to a building collapse. Monitoring of the structural displacement is the best way to discover damage immediately and to preserve the heritage building. However, the Cultural Heritage Preservation Law in Taiwan prohibits the installation of monitoring instruments (e.g strain gauge, accelerometer) in historic structures (heritage buildings). Scanning the wood structure with 3D lasers is the most non-intrusive method and quickly achieves displacement through visualization. <br><br> The displacement scan results can be compared with different periods and different members to analyze the severity of damage. Once the 3D scanner is installed, the whole building is scanned, and point clouds created to build the visual building model. The structural displacement can be checked via the building model and the differences are measured between each member to find the high risk damaged areas or members with large displacement. Early detection of structural damage is the most effective way means of preservation.

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Sadiyo, Sucahyo, Imam Wahyudi, Fengky Satria Yoresta, Nurhasanah e Muhammad Sholihin. "ANALISIS KEKUATAN SAMBUNGAN GESER GANDA ENAM JENIS KAYU PADA BERBAGAI SESARAN MENURUT DIAMETER DAN JUMLAH BAUT". PERENNIAL 8, n. 2 (1 ottobre 2012): 52. http://dx.doi.org/10.24259/perennial.v8i2.215.

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This research aims to determine the effect of double shear connection strength of six types of timber in various displacement based on diameter and the number of bolts. Six types of wood used are bangkirai, punak, meranti, sengon, bintangur and kapur. Double shear connection consists of the main member (wood) and side member (steel plate) with bolts connected. The average moisture content of sengon, meranti, bintangur and bangkirai are relatively similar (about 12 %), while kapur and punak are slightly higher at around 14 %. In contrast, the average density of six wood species are greatly vary ranging from the lowest sengon 0.26 g cm-3, to the highest 0.82 g cm-3 of bangkirai wood. The total load and load per bolt on double shear connection using bolts connector are influenced by the type of wood, diameter and number of bolts. There is a strong tendency that the higher specific gravity or density of the wood makes higher total load and load per bolt on double shear connection for each displacement. In addition, an increasing number of bolts makes the total load increased. On the other hand, it decreases load per bolts for each of bolts diameter. The use of 10 pieces of 7.9 mm diameter bolts on double shear connection for almost all type of wood produces the highest average total load compared to the other bolt diameter for both displacement 1.5 mm and 5 mm. In the same connection displacement the highest load per bolt is still obtained from using 7.9 mm bolt diameter but with the use of 4 pieces of bolts for almost all types of wood with the exception for punak and bitangur showing the highest values are obtained from 6 pieces of bolts. Bangkirai wood, kapur, punak, bintangur and meranti can be used as the main member in double shear connection by using bolt with diameter 6.4 mm, 7.9 mm and 9.5 mm because of fulfilling the requirements of PKKI (1961). Key words: Bolts, double shear connections, displacement, total load, load per bolt

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Silva, Filipe G. A., Jose Xavier, Fábio A. M. Pereira, José J. L. Morais, Nuno Dourado e Marcelo F. S. F. Moura. "Determination of cohesive laws in wood bonded joints under mode I loading using the DCB test". Holzforschung 67, n. 8 (1 dicembre 2013): 913–22. http://dx.doi.org/10.1515/hf-2013-0012.

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Abstract The cohesive laws (CLs) have been investigated by means of direct and inverse methods concerning wood bonded joints under pure mode I. The experimental results were obtained by tests with double cantilever beam. The direct method is based on the differentiation of the relation between strain energy release rate and crack opening displacement at the crack tip. An equivalent crack method was used to evaluate the strain energy release rate in the course of the test without monitoring the crack length, which is difficult to observe exactly. The crack opening displacement was determined by postprocessing local displacements measured by digital image correlation. The inverse method requires a previous assumption of the CL shape, and as such, a trilinear law with bilinear softening relationship was selected. The cohesive parameters were identified by an optimization procedure involving a developed genetic algorithm. The idea is to minimize an objective function that quantifies the difference between the experimental and the numerical load-displacement curves resulting from the application of a given law. A validation procedure was performed based on a numerical analysis with finite elements. Both methods in focus provided good agreement with the experimental data. It was observed that CLs adopted by the inverse method are consistent with the ones obtained with the direct method.

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Sebera, Václav, Miguel Redón-Santafé, Martin Brabec, David Děcký, Petr Čermák, Jan Tippner e Jaromír Milch. "Thermally modified (TM) beech wood: compression properties, fracture toughness and cohesive law in mode II obtained from the three-point end-notched flexure (3ENF) test". Holzforschung 73, n. 7 (26 giugno 2019): 663–72. http://dx.doi.org/10.1515/hf-2018-0188.

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AbstractThe fracture properties of thermally modified beech (Fagus sylvatica) wood (TMW) at 180° and 200°C were evaluated in mode II using the three-point end-notched flexure (3ENF) scheme assisted by three-dimensional (3D) stereovision equipment for obtaining displacements and strains. The compliance-based beam method (CBBM) provided the strain energy release rates (GII) of TMW and cohesive laws for both native wood (W) and TMW. Based on the CBBM and equivalent crack length approach (ECLA),GIIwas obtained directly from the force-deflection data. The thermal modification (TM) process reduced the compressive strength by 4.4% and increased the compressive elastic modulus by 38.3%, whereasGIIwas reduced substantially by 40.8% and 67.9% at TM180°Cand TM200°C, respectively. TM also increased wood brittleness that was visible on the displacement slip reduction. The resulting mean cohesive models can be used for numerical analyses. The fracture properties of TMW have to be taken into consideration for constructional wood application, when cyclic loading may lead to microcracking and material fatigue.

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İşleyen, Ümmü K., Rahim Ghoroubi, Ömer Mercimek, Özgür Anil e Recep Tuğrul Erdem. "Behavior of glulam timber beam strengthened with carbon fiber reinforced polymer strip for flexural loading". Journal of Reinforced Plastics and Composites 40, n. 17-18 (9 aprile 2021): 665–85. http://dx.doi.org/10.1177/0731684421997924.

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In the last 20 years, the use of wooden structures and their dimensions have gradually increased. The wood application has increased in different structures such as multistory buildings, sports, industrial facilities, road and railway bridges, power transmission lines, and towers. The widespread use and size of wood structures have increased the research on developing special types of wood products supported by composite materials. Laminated wood elements are the leading composite wood materials. Laminated wooden beams allow making much larger openings than standard solid wood structural elements. The development of the sizes and usage areas of wooden structures has increased the capacity of glulam structural elements and reveals the need to improve their performance. Carbon fiber reinforced polymers (CFRPs) are the most suitable options for increasing the bearing capacity values of glulam beams and improving general load–displacement behaviors. In this study, the use of CFRP strips in different layouts to increase glulam wooden beams and the application of CFRP fan-type anchors in the CFRP strip endpoints are the studied variables. Anchored and non-anchored glulam wooden beams reinforced with CFRP strips with different layouts were tested using a three-point bending test. The ultimate load capacity, initial stiffness, displacement ductility ratio, energy dissipation capacity, failure mechanisms, and general load–displacement behavior of wooden beam test specimens were obtained and interpreted as a result of the experiments.

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Abdullah, Nur Dalila, Ummi Raba'ah Hashim, Sabrina Ahmad e Lizawati Salahuddin. "Analysis of texture features for wood defect classification". Bulletin of Electrical Engineering and Informatics 9, n. 1 (1 febbraio 2020): 121–28. http://dx.doi.org/10.11591/eei.v9i1.1553.

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Selecting important features in classifying wood defects remains a challenging issue to the automated visual inspection domain. This study aims to address the extraction and analysis of features based on statistical texture on images of wood defects. A series of procedures including feature extraction using the Grey Level Dependence Matrix (GLDM) and feature analysis were executed in order to investigate the appropriate displacement and quantisation parameters that could significantly classify wood defects. Samples were taken from the KembangSemangkuk (KSK), Meranti and Merbau wood species. Findings from visual analysis and classification accuracy measures suggest that the feature set with the displacement parameter, d=2, and quantisation level, q=128, shows the highest classification accuracy. However, to achieve less computational cost, the feature set with quantisation level, q=32, shows acceptable performance in terms of classification accuracy.

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Shenton III, Harry W., David W. Dinehart e Timothy E. Elliott. "Stiffness and energy degradation of wood frame shear walls". Canadian Journal of Civil Engineering 25, n. 3 (1 giugno 1998): 412–23. http://dx.doi.org/10.1139/l97-108.

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Tests have been conducted on wood frame shear walls to characterize the degradation of stiffness and energy dissipation that occurs under cyclic loading. A total of eight walls were tested, four sheathed in plywood and four sheathed in oriented-strand board. The tests were conducted in accordance with a draft test procedure recently proposed by the Structural Engineers Association of Southern California, which is based on a sequential phased displacement command input. The results indicate that effective stiffness decreases linearly with continued cycling at the same displacement and decreases with increasing amplitudes of displacement. Furthermore, the energy dissipation capacity of the wall decreases by 15-20% with the first cycle at a given amplitude, then decreases slightly with continued cycling at the same amplitude. The changes in effective stiffness and energy dissipation are generally independent of the type of sheathing for loads less than the wall ultimate, suggesting that the wall performance under cyclic loading is influenced more by the fastener and frame behavior. The results presented should be useful for design and for verifying hysteretic models of the shear wall behavior.Key words: cyclic, dynamic, energy dissipation, experimental, seismic, shear wall, stiffness, testing, timber, wood frame.

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Tukiainen, Pekka, e Mark Hughes. "The fracture behavior of birch and spruce in the radial-tangential crack propagation direction at the scale of the growth ring". Holzforschung 67, n. 6 (1 agosto 2013): 673–81. http://dx.doi.org/10.1515/hf-2012-0139.

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Abstract Crack-tip displacement fields have been computed based on digital image correlation for spruce (Picea abies [L.] Karst.) and birch (Betula pendula Roth.) wood, which were submitted to pure mode I loading in the RT-direction under both green and air-dried conditions. Moreover, crack propagation was modeled based on both linear elastic fracture mechanics (LEFM) and nonlinear fracture mechanics, relying on the fictitious crack model (FCM). The measured and modeled load versus the crack-mouth opening displacement (CMOD) curves and displacement fields were compared. In the case of spruce, the load-CMOD curves simulated by the FCM coincide well with the measured ones. On the contrary, measured near crack-tip displacement fields in both green and air-dried spruce are better comparable with the LEFM predictions than with the FCM predictions. In the case of green birch, the simulated FCM curve follows the measured curve quite well, but in air-dried birch the simulated FCM curve has a better fit than the LEFM-curve only before maximum load. In birch, the FCM predicts the displacement fields better than the LEFM. In both species, moisture content has a big effect on the softening behavior. In both spruce and birch, the FCM overestimates the displacements ahead of crack tip, whereas the LEFM model underestimates the displacements.

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Nilsson, Christer, e Gunnel Grelsson. "The effects of litter displacement on riverbank vegetation". Canadian Journal of Botany 68, n. 4 (1 aprile 1990): 735–41. http://dx.doi.org/10.1139/b90-097.

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The hypotheses that litter deposition on riverbanks would depend on riverbank features and that litter mass would affect riverbank vegetation were tested by sampling vegetation, litter, and soil along a seventh-order stretch of the unregulated Vindel River in northern Sweden. Sampling was carried out within a horizontal litter gradient at the top of the riverbank where most of the litter deposition occurs. The amount of leaf litter left on the riverbank after flooding was significantly correlated (P < 0.05) with soil organic matter. In contrast, wood litter mass and total litter mass were not correlated (P > 0.05) with riverbank features such as soil organic matter, riverbank slope, or stem density. Species richness, species diversity, and the proportions of stemmed and nonstemmed species showed quadratic relationships (P < 0.05) with leaf litter mass, whereas ground vegetation cover decreased monotonically (P < 0.05) with increasing leaf litter mass. Tall, stemmed species were most frequent at eroded sites with low amounts of leaf litter and at sites where leaf litter had accumulated. In contrast, the highest proportion of low-growing species was found at sites with intermediate leaf litter masses. Community characteristics such as species richness, species diversity, and the proportions of stemmed and nonstemmed species (but not ground vegetation cover) were less strongly correlated with wood litter mass and total litter mass. Linear equations explained about half of the variation in ground vegetation cover along gradients of wood and total litter masses. Density and richness of seeds increased with increasing litter mass. We discuss the litter effects in terms of productivity and disturbance and conclude that flooding in pristine rivers may exert a considerable influence on riverbank vegetation as a result of litter displacement.

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Loss, Cristiano, Maurizio Piazza e Daniele Zonta. "A New Method to Assess the Seismic Vulnerability of Existing Wood Frame Buildings". Advanced Materials Research 778 (settembre 2013): 486–94. http://dx.doi.org/10.4028/www.scientific.net/amr.778.486.

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This paper aims at applying a direct displacement-based method to assess the seismic vulnerability of existing multi-storey wooden buildings. This procedure is consistent with Priestley’s direct methodology firstly developed for reinforced concrete structures. The distinctive characteristic of the proposed method is that the system response is quantified through the use of displacements instead of equivalent elastic strengths, according to the traditional force-based approaches. Consequently, in comparison to common force-based procedures, this method cannot only be considered as a rational alternative but also as a new seismic philosophy to design or assess structures. A representative timber construction system commonly used in Italy was selected as case study. The construction system illustrated in this work was analysed in detail, with special attention given to the mechanical connections typically used. The typical failure mechanisms and the energy dissipation capacity of the structure or of its members were identified on the basis of the mechanical properties of structural parts and connections, as well as of their geometry. In the proposed direct displacement-based assessment approach, the seismic intensity that would cause the limit state to be exceeded can be calculated by means of simple formulas. Therefore, the capacity to demand ratio can be simply derived. The procedure could be used to gauge the likelihood of losses, by combining it with simple loss models to account for probabilistic aspects.

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Langlois, Jeffrey D., Rakesh Gupta e Thomas H. Miller. "Effects of Reference Displacement and Damage Accumulation in Wood Shear Walls". Journal of Structural Engineering 130, n. 3 (marzo 2004): 470–79. http://dx.doi.org/10.1061/(asce)0733-9445(2004)130:3(470).

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Sathre, Roger, e Jennifer O’Connor. "Meta-analysis of greenhouse gas displacement factors of wood product substitution". Environmental Science & Policy 13, n. 2 (aprile 2010): 104–14. http://dx.doi.org/10.1016/j.envsci.2009.12.005.

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Cao, Jun, Ming Bao Li, Xiu Mei Zhang, Jia Wei Zhang e Na Zhang. "Modeling Growth Ring Mechanical Properties of Coniferous Wood Based on FEM". Advanced Materials Research 426 (gennaio 2012): 106–11. http://dx.doi.org/10.4028/www.scientific.net/amr.426.106.

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The mechanical properties’ modeling of coniferous growth ring based on finite element method is present in this paper. With the basic unit boundary conditions of stress and displacement, the constitutive relation is established between macro and micro-volume field. The multi-layer model of growth ring is 3 layers, such as early wood, transition wood and latewood layer. The first order displacement field equation is substituted into the micro-variable differential to build the balance equation which has the periodic characteristics. Single-cell finite element model is calculated out using APDL language programming, and the visual results are obtained directly by the ANSYS program output window. With the FEM model, imposing the load on it, the simulation result show that it can calculate out the mechanical properties of material. Modeling Growth Ring Mechanical Properties of Coniferous Wood based on FEM

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Majano-Majano, Almudena, Antonio Lara-Bocanegra, José Xavier e José Morais. "Measuring the Cohesive Law in Mode I Loading of Eucalyptus globulus". Materials 12, n. 1 (21 dicembre 2018): 23. http://dx.doi.org/10.3390/ma12010023.

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Assessing wood fracture behavior is essential in the design of structural timber elements and connections. This is particularly the case for connections with the possibility of brittle splitting failure. The numerical cohesive zone models that are used to simulate the fracture behavior of wood make it necessary to assume a cohesive law of the material that relates cohesive tractions and crack opening displacements ahead of the crack tip. This work addresses the determination of the fracture cohesive laws of Eucalyptus globulus, a hardwood species with great potential in timber engineering. This study centres on Mode I fracture loading for RL and TL crack propagation systems using Double Cantilever Beam tests. The Compliance-Based Beam Method is applied as the data reduction scheme in order to obtain the strain energy release rate from the load-displacement curves. The cohesive laws are determined by differentiating the relationship between strain energy release rate and crack tip opening displacement. The latter is measured by the digital image correlation technique. High strain energy release rates were obtained for this species, with no big differences between crack propagation systems. The difference between the crack systems is somewhat more pronounced in terms of maximum stress that determines the respective cohesive laws.

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Paltanea, Gheorghe, Veronica Paltanea, Dorina Popovici, George Papanicolaou e Mihael Sultan. "A Combined Model for the Stress State Evaluation in Single Overlap Joints Using Piezo-Ceramic Actuators". Materials Science Forum 792 (agosto 2014): 127–32. http://dx.doi.org/10.4028/www.scientific.net/msf.792.127.

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In this paper is presented a 2D approach to finite element modeling of a single lap bonded joint. As adherent material a sheet wood was selected and as adhesive, Bison Super Wood D3. In the article a combined method is described, consisting in the placement of piezoelectric actuators on the surface of bonded joint, in order to determine the tensile stress in the overlap joint. A comparison between the experimental, analytical and numerical results has been achieved through a multiphysics modeling - electrical and mechanical coupled problem, in order to evaluate the experimental outcomes. The experimental technique used to measure the mechanical parameters (displacements) was the three-point bending test, where different forces were applied in the mid-span of the structure, in order to maintain a constant displacement rate. The length of the overlap joint was modified from 20 to 50 mm.

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Hlavata, Vera, Pavel Kuklik e Martin Hataj. "Coefficients of Transverse Contraction of the Wood Cell Constituents and their Effect on the Cell Behavior". Key Engineering Materials 714 (settembre 2016): 20–24. http://dx.doi.org/10.4028/www.scientific.net/kem.714.20.

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Wood cells are composed of cellulose, hemicellulose, and lignin. Geometrically we can idealize them as a set of hollow cylinders touching each other on the cylinder surface. The continuous displacements and stress state transmission are assumed on the cylinder surfaces. The article investigates stress development which is influenced by the wood cell axial elongation. Material properties of individual constituents are generally described by nine parameters characterizing orthotropic elastic material. Transversely isotropic constitutive model of was chosen for simplification. The analytical solution of the stress state was driven by the ideas of displacement method. Material parameters have been estimated according to available literature. The main task of our investigation was focused on the effect of transversal contraction. The actual calculation results are surprising and lead to reflection. These considerations and conclusions are summarized at the end of the paper.

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Mikulová, P., e D. Frynta. "Test of character displacement in urban populations of Apodemus sylvaticus". Canadian Journal of Zoology 79, n. 5 (1 maggio 2001): 794–801. http://dx.doi.org/10.1139/z01-035.

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We studied the wood mouse, Apodemus sylvaticus, inhabiting parks, cemeteries, suburban woods, and other green areas in the city of Prague. To assess the character displacement and (or) release hypothesis we compared seven samples from local populations occurring sympatrically with Apodemus flavicollis with 10 samples from those localities in which A. flavicollis has never been recorded. The analysis included 1410 specimens of A. sylvaticus collected during the years 19801990. Seventeen skull and body characters were measured. Then the data were age- or size-adjusted and treated by principal-component analyses. Factor scores were further subjected to statistical testing. Although the results revealed considerable variation among localities, they did not suggest character displacement and (or) release. Apodemus sylvaticus from populations sympatric with A. flavicollis were morphometrically similar to their conspecifics from other populations collected at the periphery of the city. However, slight but statistically highly significant differences were found between samples from localities in the city centre and those from the periphery. This phenomenon may be interpreted as the effect of urbanisation or isolation by built-up areas.

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Li, Jingkui, Ruoying Wang, He Tian, Yanan Wang e Dawei Qi. "Research on the Gradual Process of the Metallization Structures and Mechanical Properties of Wood Veneer". Symmetry 10, n. 11 (26 ottobre 2018): 550. http://dx.doi.org/10.3390/sym10110550.

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In order to improve the mechanical properties of the wood surface and explore the mechanical effect of wood veneer surface metallization, the 31-year-old Pinus sylvestris is taken as the research object and Cu is deposited on the wood surface by magnetron sputtering to achieve wood veneer metallization. Based on X-ray diffraction (XRD) and nanoindentation, a research on the gradual process of the structures and mechanical properties of wood veneer metallization was carried out. The results indicate that wood veneer metallization does not affect the crystallization zone of wood, there are still wood cellulose characteristic peaks and the crystalline structure of the wood cellulose is not damaged; the thickness of the copper thin film increases with the increase of the deposition time, the cellulose characteristic peak strength gradually decrease, and the relative crystallinity also decreases; the characteristic diffraction peaks of Cu (111), Cu (200), and Cu (220) appear near the diffraction angle 2θ which is equal to 43.3°, 50.4°, and 74.1°, and the diffraction peak intensity increases with increase of deposition time, the copper film of the metal wood veneer crystallizes well; the load–displacement of wood veneer decreases significantly with the increase of deposition time, while the moduli of elasticity and hardness increase rapidly. The load–displacement of the samples which were coated for 15 min decreased by 80%, while the moduli of elasticity and hardness of these samples increased by 24.1 times and 17.3 times, respectively. From the results of Scanning Electron Microscope (SEM) measurement of the metallization of wood veneer, it can be seen that the uniform and continuous copper film can be formed on the wood veneer surface by using the magnetron sputtering method. This paper provides a basis for wood veneer surface metallization, which is of great significance for the functional improvement of wood, the expansion of wood application fields, and the enhancement of added value.

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Priyono, Dwi Joko, Surjono Surjokusumo, Yusuf S. Hadi e Naresworo Nugroho. "Equations of the Sum of Shear Connector on the Double Shear Connection Strength using Different Connector Materials". Wood Research Journal 4, n. 1 (19 aprile 2017): 81–86. http://dx.doi.org/10.51850/wrj.2012.3.2.81-86.

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Mangium wood from the timber estate have been developed continuously in an effort to reach the fulfilling of wood fiber and construction material needs to replace role of timber from the natural forests which has been decreased. Timber connection requires a connector such as bolt that can distribute both the load of wood to wood and the compression or tensile stress through all the connections. Bearing slip is a connector that is inserted into a hole in the wood, which bears pressure and shear. Bolted connection is the most commonly used because it is easy to apply, even though it is less efficient due to the shear forces will be retained by the bolts and wood only on the cross-sectional area of the bolt. This research trying to find the equations of the sum of bearing slip connector to the strength of double shear connection which composed of 17 years old mangium. The connector was made from different materials that consisted of the same mangium, compressed mangium, ironwood and steel. The bearing slip connector consisted of two forms (dowel and rectangular) and arranged on one until three pairs of connector. The size and placement of the double-shear component based on Anonymous (2002), each form of the sample was made in 4 replications and all of them have been tested using a 35-ton Baldwin UTM. The result showed that the rectangular steel bearing slip connector has the highest equation (y = 5322e0.329x ) meanwhile the lowest equation was the ironwood materials (y = 3164e0.405x ). All of equations give high correlations ( R2 between 0.743 to 0.947). Bearing slip connector can improve the ability of the connection in load-bearing. Densified of mangium able to raise the connection system's ability however not significantly, both in strength and displacement. Ironwood connector are not well used as a retaining shear pin because of easy to split and significantly much below in capacity than mangium wood. Steel connector resulted the higher load-bearing significantly than mangium and ironwood. Dowel do not differ in terms of strength as compared with rectangle, and each additional number of connector producing an increase in load-bearing ability significantly. Observation on the displacement value shows that for the value which applied usually in Indonesia reach the strength ratio (SR) as 92.21% to the proportion limit and 44.91% to the maximum load. This value was in below position of the US standard (24.17 and 11.77%) and of the Australian standard (51.46 and 25.06%) to the proportional limit and maximum load respectively. Displacement achievement at the proportional limit varies from 1.1 to 2.2 mm, so that the minimum requirement of 1.5 mm displacement is not fulfilled by some treatments, however all of the connection system have passed the 1 mm displacement.

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24

ISODA, Hiroshi, e Shinya NAKAMURA. "SEISMIC PERFORMANCE EVALUATION OF WOOD SHEAR WALLS COMBINED VARIOUS LOAD-DISPLACEMENT RELATIONSHIPS". Journal of Structural and Construction Engineering (Transactions of AIJ) 73, n. 627 (2008): 781–86. http://dx.doi.org/10.3130/aijs.73.781.

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25

Wang, Yue, David V. Rosowsky e Weichiang Pang. "Performance-Based Procedure for Direct Displacement Design of Engineered Wood-Frame Structures". Journal of Structural Engineering 136, n. 8 (agosto 2010): 978–88. http://dx.doi.org/10.1061/(asce)st.1943-541x.0000188.

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26

Hajdarević, Seid, Murčo Obućina, Elmedin Mešić e Sandra Martinović. "Stress and Strain Analysis of Plywood Seat Shell". Drvna industrija 70, n. 1 (26 marzo 2019): 51–59. http://dx.doi.org/10.5552/drvind.2019.1825.

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Abstract (sommario):

In this paper, the stress and strain analysis of common laminated wood seat shell is performed. Experimental stiffness evaluation is conducted by measuring displacement of the point on the backrest, and experimental stress analysis is carried out by tensometric measuring at the critical transition area from the seat to the backrest. Finite element analysis is carried out layer by layer with a “2D linear elastic model” for orthotropic materials. Good matching is found between numerical and experimental results of displacement. It is also shown that the results of the principal stress in the measurement points of the seat shell compare favourably with experimental data. The applied in-plane stress analysis of each individual veneer is not applicable for interlaminar stress calculations that are a significant factor in curved forms of laminated wood. Curved forms of laminated wood products require more complex numerical analysis, but the method can be used to achieve approximate data in early phase of product design.

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27

Seppälä, Jyri, Tero Heinonen, Timo Pukkala, Antti Kilpeläinen, Tuomas Mattila, Tanja Myllyviita, Antti Asikainen e Heli Peltola. "Effect of increased wood harvesting and utilization on required greenhouse gas displacement factors of wood-based products and fuels". Journal of Environmental Management 247 (ottobre 2019): 580–87. http://dx.doi.org/10.1016/j.jenvman.2019.06.031.

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28

Naghdi, R., I. Bagheri, M. Lotfalian e B. Setodeh. "Rutting and soil displacement caused by 450C Timber Jack wheeled skidder (Asalem forest northern Iran)". Journal of Forest Science 55, No. 4 (25 marzo 2009): 177–83. http://dx.doi.org/10.17221/102/2008-jfs.

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Abstract (sommario):

The use of skidding machinery in logging operations causes destructive effects especially on soil but has many advantages such as extracting long and heavy logs, optimum use of useful logging time and absence of defect in wood production quality and thus an increase in the added value of wood. In this research compartment 40 of the second district of Nav-Asalem in northern Iran at an altitude of 1,050–1,450 m above sea level was chosen in order to assess the amount of displaced soil volume and depth of ruts due to the traffic of Timber Jack 450C rubber wheeled skidder along the skid trail. Therefore, the correlations between two independent variables, longitudinal slope and soil texture, with two dependent variables, displaced soil volume and average depth of rut, along the skid trail were examined after 20 passes of skidder machinery. The results of this research showed a significant difference between the longitudinal slope increase of skid trail and the amount of soil volume displaced (<I>P</I> < 0.001). However, there was no significant correlation between the mean rut depth and different classification of longitudinal slope along the skid trail. The highest measured rut depth was 22 cm and occurred in the slope class of more than 25%. There was no significant correlation between the amount of displaced soil volume and rut depth with changes in soil texture along the skid trail.

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29

Craciun, Eduard Marius, Tomasz Sadowski, Liviu Marsavina e Adrian Rabaea. "Mathematical Aspects Regarding Cracks Behaviour in Wood Composites". Key Engineering Materials 601 (marzo 2014): 108–11. http://dx.doi.org/10.4028/www.scientific.net/kem.601.108.

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Abstract (sommario):

In this paper we study the interaction of two unequal collinear cracks in a pre-stressed fiber reinforced wood composite material in anti-plane mode of fracture. A mathematical model is associated to the mechanical problem. Starting from the boundary, constitutive and far field conditions we obtain the representation of the incremental displacement, stress and strain fields using two complex potentials. Using Sih s generalized fracture criterion we determine the critical incremental shear stress which produce crack propagation and the crack tips propagation direction in a particular case of a Pine wood composite.

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30

Parameswaran, V. R. "Adfreezing strength of ice to model piles". Canadian Geotechnical Journal 24, n. 3 (1 agosto 1987): 446–52. http://dx.doi.org/10.1139/t87-055.

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Abstract (sommario):

Results of tests to determine the adfreezing strength of freshwater ice to piles having different surface characteristics show that adfreeze strength increases with increase in the rate of displacement and loading of the pile. Surface coatings such as creosote on wood piles and paint and silicone sealer on metallic piles drastically decrease the adfreezing strength of ice. Key words: adfreezing strength, displacement rate, ice, loading rate, model piles, surface coating.

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31

Craciun, Eduard Marius, e Tomasz Sadowski. "Mathematical Modelling of the Crack Propagation in Wood Materials". Key Engineering Materials 399 (ottobre 2008): 177–82. http://dx.doi.org/10.4028/www.scientific.net/kem.399.177.

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Abstract (sommario):

In this paper we study the behaviour of a Mode I crack in a pre-stressed wood composite material. A mathematical model is associated to the mechanical problem. Starting from the boundary, constitutive and far field conditions we obtain the representation of the incremental displacement, stress and strain fields using two complex potentials. Using numerical analysis we determine the critical value, which causes crack propagation and the direction of crack propagation in a particular case of a Pine wood composite.

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32

Poltorak, Benjamin J., Eric R. Labelle e Dirk Jaeger. "Soil displacement during ground-based mechanized forest operations using mixed-wood brush mats". Soil and Tillage Research 179 (giugno 2018): 96–104. http://dx.doi.org/10.1016/j.still.2018.02.005.

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33

Vrtiska, Mark P., Richard M. Kaminski, Harold H. Prince e John D. Thompson. "Geographical displacement and timing of molt of the remiges in male Wood Ducks". Canadian Journal of Zoology 75, n. 9 (1 settembre 1997): 1545–48. http://dx.doi.org/10.1139/z97-780.

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Abstract (sommario):

Captive wild-strain male Wood Ducks, Aix sponsa, reared in Mississippi and transported to Michigan and Illinois in 1993 and 1994 were used to test the effect of geographical displacement and age on timing of molt of the remiges. Males transported to both northern sites initiated remex molt later (P = 0.0001) in 1993 than males remaining in Mississippi. In 1994, males continued to molt later at northern sites than in Mississippi, but earlier molting at both northern sites in 1994 than in 1993 resulted in no detectable differences (P = 0.31) in molting date. Although there were no differences (P > 0.05) in date of remex molt between adult and yearling males in 1992 and 1993, molt occurred earlier (P = 0.0006) each year for birds remaining in Mississippi during 1992–1994. Timing of remex molt in male Wood Ducks may be influenced by photoperiodic, environmental, and social cues associated with geographical displacement, but other factors (e.g., genetics) may also influence annual timing.

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34

Poirier, N. A., W. J. M. Douglas e R. H. Crotogino. "Axial dispersion models for displacement washing of packed beds of wood pulp fibres". Canadian Journal of Chemical Engineering 66, n. 6 (dicembre 1988): 936–44. http://dx.doi.org/10.1002/cjce.5450660607.

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35

Sandak, Jakub, e Chiaki Tanaka. "Evaluation of surface smoothness by laser displacement sensor 1: effect of wood species". Journal of Wood Science 49, n. 4 (agosto 2003): 305–11. http://dx.doi.org/10.1007/s10086-002-0486-6.

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36

Chen, C. Y., F. A. Boudreault, A. E. Branston e C. A. Rogers. "Behaviour of light-gauge steel-frame – wood structural panel shear walls". Canadian Journal of Civil Engineering 33, n. 5 (1 maggio 2006): 573–87. http://dx.doi.org/10.1139/l06-015.

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Abstract (sommario):

The second phase of the research project to develop a shear wall design method that could be used in conjunction with the 2005 National Building Code of Canada involved evaluation of the performance characteristics of the tested steel-frame – wood structural panel shear walls. A nonlinear and pinched resistance versus deflection hysteretic behaviour was exhibited, although in most cases the walls could sustain large inelastic deformation cycles with limited strength degradation. A significant amount of energy could be dissipated under reversed cyclic loading. Walls 1220 mm and 2440 mm in length were able to develop their maximum capacity at similar displacement levels; however, the 610 mm long walls required significantly larger displacements prior to reaching their ultimate shear resistance. The performance of the walls was directly linked to the behaviour of the sheathing-to-framing screw connections, except in one case in which local buckling of the chord studs controlled the ultimate shear resistance. Given the behaviour observed during testing, this type of wall construction can be relied on to resist lateral loading, including earthquake effects in the inelastic range, assuming the designer ensures that failure of the wall is limited to the sheathing-to-framing connections.Key words: shear wall, light-gauge steel, wood structural panel, earthquake, wind.

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37

Oliveira, Jorge, José Xavier, Fábio Pereira, José Morais e Marcelo de Moura. "Direct Evaluation of Mixed Mode I+II Cohesive Laws of Wood by Coupling MMB Test with DIC". Materials 14, n. 2 (14 gennaio 2021): 374. http://dx.doi.org/10.3390/ma14020374.

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Abstract (sommario):

Governing cohesive laws in mixed mode I+II loading of Pinus pinaster Ait. are directly identified by coupling the mixed mode bending test with full-field displacements measured at the crack tip by Digital Image Correlation (DIC). A sequence of mixed mode ratios is studied. The proposed data reduction relies on: (i) the compliance-based beam method for evaluating strain energy release rate; (ii) the local measurement of displacements to compute the crack tip opening displacement; and (iii) an uncoupled approach for the reconstruction of the cohesive laws and its mode I and mode II components. Quantitative parameters are extracted from the set of cohesive laws components in function of the global phase angle. Linear functions were adjusted to reflect the observed trends and the pure modes (I and II) fracture parameters were estimated by extrapolation. Results show that the obtained assessments agree with previous experimental measurements addressing pure modes (I and II) loadings on this wood species, which reveals the appropriateness of the proposed methodology to evaluate the cohesive law under mixed mode loading and its components.

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38

Sadiyo, Sucahyo, e Emma Yusrina Wulandari. "PENGARUH DIAMETER DAN JUMLAH PAKU TERHADAP KEKUATAN SAMBUNGAN GESER GANDA BALOK KAYU NANGKA (Artocarpus heterophyllus) dan RASAMALA (Altingia excelsa Noronha) DENGAN PELAT BAJA". PERENNIAL 8, n. 1 (1 aprile 2012): 36. http://dx.doi.org/10.24259/perennial.v8i1.213.

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Abstract (sommario):

The application of nail connection for part of the structural construction in Indonesia is still become the main choice. Connection type that must be counted on seriously for structural construction, are tension, shear and momen connection. Nangka wood is a type of woods that available in sawing or community woods work around Bogor. Rasamala is endemic and unique woods from West Java. Nails as connection are cheap, available and workable. This research objective is to investigate the effect of diameter and amount of nails to double shear connection strength on two type of woods. The results showed that the increase of diameter and amount of nail will rise the capacity of total allowable load per shear plane (RT) or double shear connection strength of nangka woods and rasamala-steel plate, but this phenomena is different for allowable load capacity per nail per shear plane (R) for both of that type. Design value for nangka wood based on diameter size 4,1; 5,2 and 5,5 mm are 261; 358 and 365 kg respectively, and for rasamala wood the design value is sligthly low, which is 227; 311 and 321 kg respectively. The minimum value becomes fundamental for determining design value of total allowable load per shear plane connection (RT) based on amount of nail (4-10), which is determined by multiply the value of certain type woods with amount of nails used. Key words: double shear, displacement, allowable load per nail per shear plane (R), total allowable load per shear plane (RT)

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39

Persi, Elisabetta, Gabriella Petaccia, Stefano Sibilla, Roberto Bentivoglio e Aronne Armanini. "A One-Way Coupled Hydrodynamic Advection-Diffusion Model to Simulate Congested Large Wood Transport". Hydrology 8, n. 1 (27 gennaio 2021): 21. http://dx.doi.org/10.3390/hydrology8010021.

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Abstract (sommario):

An advection-diffusion model is proposed to simulate large wood transport during high flows. The mathematical model is derived from the wood mass balance, taking into consideration both the wood mass concentration and the log orientation, which affects log transport and, most importantly, wood accumulation. Focusing on wood mass transport, the advection-diffusion equation is implemented in a hydrodynamic model to provide a one-way coupled solution of the flow and of the floating wood mass. The model is tested on a large series of flume experiments, involving at least 30 logs and different control parameters (flow Froude number, log length, diameter, release point). The validation through the experimental data shows that the proposed model can predict the correct displacement of the most probable position of the logs and to simulate with a sufficient accuracy the planar diffusion of the wooden mass. Transversal wood distribution is more accurate than the streamwise one, indicating that a higher control on the longitudinal diffusion needs to be implemented.

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40

Sebera, Václav, e Jan Tippner. "Possible use of the hyperelastic material models in numerical analysis of the wood-strand mat compression". Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 57, n. 4 (2009): 83–94. http://dx.doi.org/10.11118/actaun200957040083.

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Abstract (sommario):

The main goal of the work was to evaluate a possibility of using various hyperelastic material models implemented into ANSYS computational system for the numerical analysis of wood-strand mat pressing or wood-based composites. Subsequently, the most suitable hyperelastic model was used as a material model in compression simulation. Pressing itself was modelled as a contact transient analysis with wood-strand mat being defined as a homogenous and isotropic continuum with the chosen material model. In the analysis only displacement degrees of freedom are considered. Output of the simulation is a contact pressure, which is necessary to apply to compress the mat on the required height. The analysis serves as a take-off platform for further research in wood-based composites pressing process.

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41

Rittenhouse, Tracy A. G., e Raymond D. Semlitsch. "Behavioral response of migrating wood frogs to experimental timber harvest surrounding wetlands". Canadian Journal of Zoology 87, n. 7 (luglio 2009): 618–25. http://dx.doi.org/10.1139/z09-049.

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Abstract (sommario):

Behavioral responses to ecological disturbances such as timber harvest, fire, or drought provide insight into wildlife habitat requirements. To determine the behavioral response of adult wood frogs ( Lithobates sylvatica (LeConte, 1825)) to timber harvest in oak–hickory forest, we conducted experimental timber harvest surrounding replicate breeding sites, monitored freely moving frogs using radiotelemetry, and tested the repeatability of behavioral responses with two experimental displacements. We found no evidence that wood frogs use recent oak–hickory clearcuts as habitat. Timber harvest was not a complete barrier to movement, as frogs surviving increased predation and desiccation risks reached drainages used as nonbreeding habitat. Frogs did not alter the direction of travel and traversed similar distances (i.e., total distance and net distance from breeding site) before and after timber harvest. However, rate of travel (i.e., maximum distance traversed in 1 day) increased following timber harvest and frogs displaced to the center of clearcuts exited the timber harvest array in one rainy night. Notably, wood frogs following displacement exhibited site fidelity to nonbreeding habitat. We suggest that deleterious effects of timber harvest on amphibians may be minimized through the use of small stand sizes placed in locations that do not separate breeding and nonbreeding habitat.

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42

Fajdiga, Gorazd, Denis Rajh, Branko Nečemer, Srečko Glodež e Matjaž Šraml. "Experimental and Numerical Determination of the Mechanical Properties of Spruce Wood". Forests 10, n. 12 (13 dicembre 2019): 1140. http://dx.doi.org/10.3390/f10121140.

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Abstract (sommario):

The objective of this paper is the computational and experimental study of the fracture behavior of spruce wood under quasi-static loading conditions during a three-point bending test. The experimental tests were performed on the electronic testing machine Zwick Z100 (Zwick-Roell GmbH & Co. KG, Ulm, Germany) with displacement control, according to the standard International Standard Organisation (ISO) 13061-4: 2014. The specimens were made of Norway spruce (Picea abies) wood, with dimensions of 25 mm × 25 mm in cross-section and 549 mm in length. Six tests were performed for each orientation (radial and tangential) of the wood fibres. Based on the experimental results, the computational model was created and validated by considering the mechanical responses in two different directions due to the orientation of the wood fibres. An orthotropic material model with damage evolution was selected as the computational model. The computational model was validated using the inverse procedure for the determination of the constitutive material parameters, including the damage parameters of three-point bending test specimens. A finite element method (FEM) in the framework of program package ABAQUS was used for the computational simulation, while the open code Optimax was used for the optimization procedure. Comparison between the experimental and computational force vs. the displacement response showed a very good correlation in the results for the spruce wood specimens under three-point bending tests, with Pearson′s correlation coefficient of r = 0.994 for the tangential and r = 0.988 for the radial orientation. Therefore, validation of the proposed computational model was confirmed, and can be used further in numerical simulations of the fatigue behavior of wood specimens.

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43

Huang, Yi Hui, e Meng Ting Tsai. "Amplification Factor for Wood-Concrete Hybrid Structures Based on Dynamic Numerical Simulation". Key Engineering Materials 873 (gennaio 2021): 65–69. http://dx.doi.org/10.4028/www.scientific.net/kem.873.65.

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Abstract (sommario):

Extensive concerns on environmental protection have provoked low-carbon buildings to be the mainstream of building construction worldwide, and wooden structures in this sense outperform other structural forms. Wooden-concrete hybrid structures featuring distinct wooden and concrete stories typically exhibit uneven stiffness distribution along the structure height; in particular, abrupt stiffness changes occur at the wood-concrete transition stories. Therefore, structural designing of such hybrid structures must consider a stiffness amplification effect in the static structural calculation as well as complicated procedures in the dynamic analysis. To determine an appropriate amplification factor for design purpose, this study employed a dynamic numerical approach to determine the displacement response of wooden-concrete hybrid buildings and compared the results with the displacement response obtained from static analyses. According to the results, it is found that the appropriate amplification factor should beα= f (x) = 0.47x + 1.00.αcan be valued 1.94 at 2nd floor, 2.41 at 3rd floor and 2.88 at 4th floor. The results may serve as a reference for seismic designing of wooden-concrete hybrid structures.

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44

Pearson, Hamish, Sigurdur Ormarsson e Brian Gabbitas. "Nonlinear tensile creep behavior of radiata pine at elevated temperatures and different moisture contents". Holzforschung 69, n. 7 (1 settembre 2015): 915–23. http://dx.doi.org/10.1515/hf-2014-0240.

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Abstract (sommario):

Abstract Tensile wood creep has not been measured previously in the temperature region 135°C–150°C for a range of moisture content (MC) up to fiber saturation point due to equipment and measurement challenges. Yet this is the region where the most dramatic softening effects can be observed. The aim of this study was to develop specialized equipment to measure tensile solid wood creep over 70°C–150°C for a range of MC and loads. Creep displacement was successfully able to be isolated from elastic and mechanosorptive strains and statistically modeled by regression analysis. This proved more accurate than complex series expansions consisting of spring- and dashpot-type components. The best creep displacement relationship was a power law with a strain root mean square error of 0.28%. The amplitude of the power law was nonlinear with respect to stress and temperature and changed by a stress factor of up to 0.9 for a stress of up to 1.2 MPa and by a temperature factor 1.2–6.3 over the investigated range. The creep relationship provides a valuable tool for predicting time-dependent distortion and internal stress of wood during drying or thermohygromechanical modification below 150°C.

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45

Ntenga, Richard, Serges Lahe, Jean Atangana Ateba e Tibi Beda. "Numerical Simulations of Azobé/Urea Formaldehyde Wood Plastic Composite Behaviors under Charpy Impact and Low-Velocity Drop Weight Tests". Journal of Composites Science 2, n. 4 (17 ottobre 2018): 60. http://dx.doi.org/10.3390/jcs2040060.

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This work is concerned with the study of the influence of impactor’s velocity parameters, impactor’s geometry, the target plate properties, and thickness, on the response of a tropical wood plastic composite (WPC) Azobé/urea formaldehyde (Az/UF) plate under impact loading. Variations of the impact force, displacement, deformation, and impact energy of the specimens with weight fractions of 10, 20, 30, 40, and 50% have been considered in finite element analysis (FEA) simulations. The simulations of the Charpy and of a drop weight impact test on the WPC were carried out using the explicit dynamics module of ANSYS Workbench, which handles problems of dynamic loading of a short duration for 2D and 3D analyses. Contact laws that account for the compressibility of the interacting bodies (the standard steel impactor and the WPC target plate), have been used. The results show that the displacements decrease in contrast to the increase of the wood filler content, and vary in the 6.8–9.0 mm interval. From an energetic point of view, it is observed that the maximum absorbed energy is between 40 and 50% for the Azobe flour wt.%, with energy absorption rates of 28% and 26% of the total energy. These results are in agreement with those reported in previous experimental investigations on hybrid WPCs filled with wood flour and glass fibers, which produce an energy absorption rate of 24–26%. These results promote the applicability of Azobé tropical wood in fabricating WPCs for impact loading situations.

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46

Wolf, Christian, Daniel Klein, Klaus Richter e Gabriele Weber-Blaschke. "Mitigating environmental impacts through the energetic use of wood: Regional displacement factors generated by means of substituting non-wood heating systems". Science of The Total Environment 569-570 (novembre 2016): 395–403. http://dx.doi.org/10.1016/j.scitotenv.2016.06.021.

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47

Li, Chao, Xilong Wang e Yizhuo Zhang. "Structural design and mechanical properties analysis of bamboo-wood cross-laminated timber". BioResources 15, n. 3 (27 maggio 2020): 5417–32. http://dx.doi.org/10.15376/biores.15.3.5417-5432.

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Abstract (sommario):

To explore the overall mechanical properties of bamboo-wood composite cross-laminated timber (BCLT), a simulation model of BCLT mechanical behavior based on the solid element was established using the finite element software ABAQUS. The actual four-point bending experiment was compared and analyzed with the finite element numerical simulation. The total curve error coefficient of the BCLT specimen at 18-mm displacement was 0.2988 while the interval was 0.5 mm. The error coefficient was 0.0178 when the maximum load was reached, and the minimum error coefficient was 0.0015 at 12 mm of displacement. Analysis of the influence of material parameters, meshing density, and material arrangement on the final stress distribution indicate that the difference in the elastic parameters of the material greatly influence the final stress distribution, and the arrangement and combination of materials also have an effect on the overall mechanical properties of the BCLT board. The combination CLT1-2-1 (i.e., the upper and lower layers of the bamboo are Arrangement 1 and the hemlock is Arrangement 2) have a maximum load of 57682 Ν and a maximum stress of 103.9 MPa.

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48

ISODA, Hiroshi. "VERIFICATION OF HYSTERESIS MODEL OF WOOD SHEAR WALL CONSIDERING OF LARGE DISPLACEMENT UNDER EARTHQUAKES". Journal of Structural and Construction Engineering (Transactions of AIJ) 76, n. 659 (2011): 113–20. http://dx.doi.org/10.3130/aijs.76.113.

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49

Pang, Wei Chiang, e David V. Rosowsky. "Direct Displacement Procedure for Performance-Based Seismic Design of Mid-Rise Wood-Framed Structures". Earthquake Spectra 25, n. 3 (agosto 2009): 583–605. http://dx.doi.org/10.1193/1.3158932.

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Abstract (sommario):

This paper presents a direct displacement design (DDD) procedure that can be used for seismic design of multistory wood-framed structures. The proposed procedure is applicable to any pure shear deforming system. The design procedure is a promising design tool for performance-based seismic design since it allows consideration of multiple performance objectives (e.g., damage limitation, safety requirements) without requiring the engineer to perform a complex finite element or nonlinear time-history analysis of the complete structure. A simple procedure based on normalized modal analysis is used to convert the code-specified acceleration response spectrum into a set of interstory drift spectra. These spectra can be used to determine the minimum stiffness required for each floor based on the drift limit requirements. Specific shear walls can then be directly selected from a database of backbone curves. The procedure is illustrated on the design of two three-story ATC-63 archetype buildings, and the results are validated using nonlinear time-history analysis.

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50

Rossi, Simone, Ivan Giongo, Daniele Casagrande, Roberto Tomasi e Maurizio Piazza. "Evaluation of the displacement ductility for the seismic design of light-frame wood buildings". Bulletin of Earthquake Engineering 17, n. 9 (8 giugno 2019): 5313–38. http://dx.doi.org/10.1007/s10518-019-00659-4.

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