Wooden Beams Research Articles

The Analysis of Screws Spacing Effect On The Flexural Strength Of Laminated Wood Beams From Pine Pallets Waste

Pine pallets are often used to design the interior of houses, as opposed to pine waste, which is underutilized due to its reduced strength and limited size. Therefore, this research aims to optimize the use of pine pallet waste by making laminated beams using screw joints and determining the effect of screw spacing on the strong bending of laminated beams. Flexural strength tests of laminated wood beams measuring 5 cm x 5 cm x 76 cm with varying screw spacing of 4 cm, 8 cm, 12 cm, and 16 were used to conduct this research. This is in addition to screw length, head, and body diameters of 5 cm, 8 mm, and 4 mm, respectively. Strong bending testing was carried out at the Structural Laboratory of the Department of Civil Engineering, Faculty of Engineering, Tidar University, Magelang. The test results of consecutive Modulus of Rupture (MOR) had average values of 20.996 MPa, 23.067 MPa, 20.207 MPa, 19.292 MPa. and Modulus of Elasticity (MOE) of 1,352.68 MPa, 1,449.35 MPa, 1,146.76 MPa, and 1,128.90 MPa. The result showed that the use of varying screw spacing has no significant effect on the flexural strength of laminated beams. Furthermore, the laminated pine pallet waste with screws can be used as an alternative to pure wood by paying attention to the proper joint spacing.

The Application of The Indigenization Technique in Modern Chinese Church Architecture

"Indigenization" is a process that presents a blend and adaptable feature by combining foreign elements with the local natural environment and cultural factors. Church buildings are the most tangible manifestation of the "indigenization" of Christianity. This paper discusses the application of indigenization techniques in modern Chinese Catholic church architecture from four aspects: layout, structure, materials, and decoration. In terms of layout, indigenization is reflected in space, plan, and orientation. The space mainly imitates traditional Western-style churches and simplifies with the simplification of function. In terms of plan form, the basic rectangular space is retained and combined with local architectural features to evolve into some new variants. Orientation, some churches have absorbed local building orientation patterns. In terms of structural indigenization, the main materials are stone, brick, and soil, and the building structure is mainly supported by load-bearing walls and wooden beams. In terms of material selection, indigenization techniques are mainly based on regional resource conditions and are combined with the characteristics of local residences and climate conditions. The choice of building materials is made by considering the availability, processing difficulty, and physical properties of materials. The application of decorative indigenization often borrows common decoration techniques from local residential buildings and combines them with traditional Chinese culture to create a unique Chinese and Western fusion style building, making the church better integrated into the local architectural community and accelerating local residents' acceptance of Catholicism.

Investigasi Visual Kelayakan Bangunan Publik di Desa Jamblang

Many functional old buildings and geological condition in Indonesia are prone to disasters, hence, the investigation is needed whether those buildings are still feasible to use. Periodic inspection is one of the methods to review the buildings by standard provisions. In this study, a survey was carried out based on Permen PU No. 16/RTM/2010 and Rapid Visual Screening (FEMA P-154). Both methods were used a special form that investigates the building visually. The purpose of the study was to investigate the existing building by reviewing the damage level of building components from the structural, architectural, mechanical, and electrical aspects, as well as to seismic hazards. Based on the Minister of Public Works Regulation Number 16/RTM/2010, the results show that there are several weathered wood columns and beams, cracked walls, and many piping and electrical that are no longer functioning. Based on Rapid Visual Screening (FEMA P-154), the final value of form level 2 is 0,2 which is similar with the SMin value, which indicating that the condition of the meeting building in Jamblang Village is categorized as prone to seismic hazards, therefore, the structure strengthening is required.

Structures of Wooden Beams of Increased Load-Bearing Capacity

The article suggests the use of glued reinforced wooden beams with increased load-bearing capacity. The beam is provided with reinforcing elements in the grooves, namely, in the lower zone – prestressed flexible bundles made of composite, and in the upper zone – steel rods. The analysis of structural behaviour of the beam and the location of the reinforcing elements, the calculation of the bearing capacity of beams and evaluation of the effectiveness decision on material and Flexural rigidity. Composite rods can be prestressed to increase the efficiency of the reinforcement and increase the beam stiffness and load-bearing capacity. Installation of reinforcing elements along the line of action of the main tensile stresses in a wooden beam creates tension in them, which allows the use of flexible bundles and leads to a decrease in the complexity of their installation in the lower grooves, and, therefore, reduces the complexity of manufacturing a wooden beam as a whole.

Non-contact Ultrasonic Sonar-based Ranging Technique for In-motion 3D Railroad Tie Deflection Measurements

This paper presents an ultrasonic technique for non-contact surface deflection mapping of railroad ties using concepts of sonar-based ranging. The technique utilizes an array of capacitive ultrasonic transducers arranged along the length of the railroad tie at a lift-off distance of 3 in. from the rail surface to ensure contactless measurements. The transducer array is used in pulse-echo mode and distances from the transducers to the tie surface are measured by tracking the time-of-flight of the waves reflected from the tie surface. A reference-based cross-correlation operation is introduced to compute the time-of-flight, wherein one of the transducers is used as a reference for the distance measurements. The reference-based cross-correlation ensures accurate peak-detection for time-of-flight based differential distance measurements. An acoustic signal strength-based technique is utilized to differentiate between signals reflected from ties and those reflected from ballast. Laboratory scale tests were first performed as a proof-of-concept on a slender wooden beam to measure deflections in loaded and unloaded conditions. Dynamic tests were also performed on this beam to determine the ability to track time-varying positions. Field tests on a replica test track with wood ties were performed at the Rail Defect Testing Facility at University of California San Diego by mounting the prototype on a test-cart moved at walking speed. A dynamic assessment of the prototype was also performed to determine natural frequencies of the mounting beam that may be relevant for future uses at higher speeds. The results indicate the potential of this non-contact system to measure full-field tie deflections in 3D in-motion. This ability may potentially be used to detect conditions of poor tie support that may cause derailments.

Implementation of an Optical Measurement Method for Monitoring Mechanical Behaviour

There is a gap between mechanical measurement methods under laboratory conditions and those under real conditions of structural monitoring. This paper proposes a method that applies well-established computer vision developments to photomechanics in difficult conditions. It is therefore a technique that is flexible and versatile while maintaining satisfying accuracy. It consists in marker tracking using ArUco fiducial markers as measurement points. It allows locating markers in non-optimal conditions of camera orientation and position. A homography process was used to analyse pictures taken with a view angle. The accuracy of the method was estimated, especially in case of out-of-plane motions, and the impact of the view angle and of the distance between camera and markers on the location error was studied. The method was applied in creep tests to measure crack parameters as well as the transverse expansion of wooden beams. In the application example presented, it enabled to compute distances between markers with only 0.28% of relative error and hence to measure the crack parameters and the long-term shrinkage-swelling of the wooden beams. However, the impacts of brightness variations and camera parameters have not been estimated. This method is very promising when experimental conditions are variable and when multiple measurements are necessary.

Wood Beam Damage Identification Based on the Curvature Mode and Wavelet Transform

In the paper, a simple-supported wooden beam is used as the research object to identify the damage of the wood beam by finite element analysis and experimental research. First, ANSYS was used to establish the solid finite element model of the wood beam before and after the damage, and then the discrete wavelet transform was performed on the curvature mode of the wood beam before and after the damage, and the wavelet coefficient difference index was obtained after obtaining the high frequency wavelet coefficients. Then, the damage location of the wood beam was judged according to the sudden peak of the wavelet coefficient difference index, and the damage degree of the wood beam was estimated by fitting the relationship between the wavelet coefficient difference index and the degree of damage. Finally, the index was verified by the wooden beam test. The results show that the wavelet coefficient difference index can accurately identify the damaged location of the wood beams. The degree of damage to the wood beams at the damage location can be quantitatively estimated by fitting the relationship between the wavelet coefficient difference index and the degree of damage at the damage location. The research results provide a theoretical basis to identify wooden beam damage.

Experimental Analysis of the Performance of Doweled Connections Reinforced with Glass-Fiber-Reinforced Polymer (GFRP) in Wood Pinus spp.

In line with technological advancements, the construction industry worldwide has sought more efficient building systems in relation to aspects such as increased productivity, reduced material waste and meeting the growing demand. The objective of this research was to use structural joints composed of composite dowels in laminated wood beams as an alternative to connect pieces of wood. Composite materials are composed of a matrix phase and a reinforcement phase and, in civil engineering, are generally applied as reinforcements in concrete structures. This article presents the structural performance of laminated pine timber with composite dowels made of fiber-reinforced polymeric resin (epoxy resin, hardener and glass fiber) (glass-fiber-reinforced polymer, GFRP) with a diameter of 12.5 mm, which was subjected to tensile force in the direction of the connection. For this, an experimental program was carried out that included characterization of the GFRP dowel, characterization of the woods used to make the connection and a tensile test of the connections with the dowels reinforced with fiberglass through a prototype designed specifically for the test. Subsequently, the results were compared with those observed in the literature. In the comparisons, it was possible to conclude that the joints with FRP pins exhibited better performance in terms of shear strength per section than those such as common nails, helical nails (Ardox) and composite structural pins (half-lap, 90°), which were 3.8 mm, 3.4 mm and 6 mm in diameter, respectively. This indicates that this composite material has potential for application in these types of connections. As an original contribution, it proves the feasibility of using this material in dowel joints for wooden structures.

Catenary action in strip-reinforced wood and timber beams

At present, the popularity of timber as a structural material is booming. However, the current knowledge on disproportionate collapse prevention and extreme loading of timber buildings is scarce. To prevent disproportionate and progressive collapse, catenary action is an important mechanism, where the axial capacity of bending members is activated. Because of the brittle behavior of timber in the relevant failure modes, it can only achieve catenary action via strengthening. In this paper, analytical expressions are derived for the elastic, plastic, and catenary capacity of laterally loaded wood and timber beams with a tension-side strip reinforcement. A load-path dependent M-N interaction diagram with damage accumulation explains the ultimate catenary capacity and the transition between the bending- and catenary-dominated load-carrying mode. The analytical expressions are validated and discussed based on tests on beech clearwood specimens reinforced with carbon fibers in a polyurethane matrix. Furthermore, a case study on glued laminated timber beams is presented to demonstrate the potential of reinforcing timber beams subjected to extreme loading.

ANALISIS FAKTOR PENYEBAB MASYARAKAT LAMA MEMBANGUN RUMAH BERBENTUK PERSEGI PANJANG DAN KESESUAIANNYA TERHADAP PRINSIP RUMAH TAHAN GEMPA

As an earthquake prone area, building earthquake-resistant houses is a basic necessity for Bengkulu Province residents. The simple symmetrical house plan provides better structure to withstand earthquakes. Batu Kuning is a village located in Ulu Manna District, South Bengkulu Regency, Bengkulu Province. This village is a village that was affected by the earthquake in 2000 and 2007, as well as other earthquakes, although the impact was not as big as the two earthquakes. In the event of the earthquake, several houses were not heavily damaged or destroyed so they are still inhabited today. Observations made by the author found a tendency for the shape of the house to be simple, symmetrical and tend to be rectangular. The research method was carried out by distributing questionnaires to respondents with a total of 26 samples. The results of the questionnaire were processed and analyzed using the SPSS Version 26 program, which included data validity and reliability tests. The results obtained showed 26.72% in strength and resilience factors, 25.63% in economic and cost factors, 25.63% in construction factors, and 22.02% in customs and environmental factors. The dominant factor is the construction factor, with an indicator that the construction of a rectangular house is easier to work on. The suitability level of old people's houses with the principle of earthquake-resistant houses shows that 73.08% uses a continuous river stone foundation with a depth of more than 45 cm. 92.31% of the old community house structure in Batu Kuning Village, Ulu Manna Subdistrict, using wooden columns and beams. The use of lightweight (zinc) roofs is in accordance with the principles of building earthquake-resistant houses.

Struktur Dan Desain Bangunan Tradisional Bali Di Banjar Cekeng, Desa Sulahan, Bali

The structure and design of traditional Balinese buildings are still great features, especially when it comes to keeping culture, society, and religion alive in old buildings. Research on building design structures still needs to be reported. This study aims to analyze the structure and design of traditional Balinese buildings in Banjar Cekeng, Sulahan Village, Bali. The mixed method study design was used to direct residents of Br Cekang to sekanem and Paon buildings. Data analysis is carried out descriptively. As a result, the traditional Balinese structure and design of the Sakanem and Paon (kitchen) in Banjar Cekeng meet SNI based on structural analysis. The findings show the strength of the structure for the beams and that the bale Sakanem and Paon horses have sufficient vertical rigidity to withhold the working boundary loads. Furthermore, at the lateral deviation of the Sakanem and Paon building structures, they have sufficient lateral rigidity to withstand the earthquake loads in the x and y directions. Maximum factored force analysis obtained the results of the structures of models 1 (Sakanem), consisting of column and beam structure components made of wooden material, and models 2 (Paon), with concrete column structure components, bamboo, and wooden beams. The nominal bending and sliding capacities of Sakanem and Paon beams are greater than the ultimate bending and sliding capacities. The combined capacity of bending and axial columns in Sakanem and Paon buildings is smaller than the bending and axial capacity of ultimate and practical columns in Paon buildings, not crossing the interaction boundary line.

Near-field measurements for wood anisotropy using cavity-backed slot antennas

Wood is becoming a very important structural material for buildings because it is a renewable resource and has a very small carbon footprint. This paper reports an experimental study on the effect of annual rings on wood anisotropy measurements using near-field microwave scanning for Pine, Hemlock, Red Cedar, and Hardwood laminated wood beams. Transmission measurements show significant anisotropy (>10 dB) for Pine wood compared to Hemlock wood and Red Cedar wood for linear polarization. The effect of annual rings in guiding the transmitted signal through wood fibers is observed through transmission measurements. Microwave guidance in transmission disappears with increasing the moisture content (17%–138%) of the Pine wood sample. The study provides a novel, accurate, fast, low-cost structural-wood testing method based on cavity-backed slot antennas for transmission and reflection measurements.

Travelling with Architect Erik Hansen: A Cypress on the Peloponnese

Abstract This reflective article starts with a personal anecdote, a journey together with Erik Hansen on the Peloponnese to visit an old cypress. He describes Hansen’s empathetic working method, which leads to a better understanding of the whole construction process of the temple. An essential part was the building of an evenly ascending slipway on the steep hillside, which could comply with the limits of the tractive force and the load put on the constructed track by the transport of the building blocks and wooden beams. This slipway was used to transport around 2,000 building blocks with a total volume of more than 3,000 m3. The total dragging operation included over 8,000 tons of blue-grey limestone.

Static Analysis of Wooden Beams Strengthened with FRCM-PBO Composite in Bending

The article presents an analysis of the static work of bent solid-wood beams reinforced with FRCM-PBO (fiber-reinforced cementitious matrix-p-phenylene benzobis oxazole) composite. In order to ensure better adhesion of the FRCM-PBO composite to the wooden beam, a layer of mineral resin and quartz sand was applied between the composite and the wooden beam. Ten wooden pine beams with dimensions of 80 × 80 × 1600 mm were used for the tests. Five wooden beams, unreinforced, were used as referenced elements and another five were reinforced with FRCM-PBO composite. The tested samples were subjected to a four-point bending test in which the static scheme of a simply supported beam subjected to two symmetrical concentrated forces was used. The main purpose of the experiment was to estimate the load capacity, the flexural modulus and the maximum bending stress. The time needed to destroy the element and the deflection were also measured. The tests were carried out based on the PN-EN 408: 2010 + A1 standard. The material used for the study was also characterized. The methodology and assumptions adopted in the study were presented. The tests confirmed a significant increase in destructive force by 141.46%, maximum bending stress by 118.9%, modulus of elasticity by 18.32%, time needed to destroy the sample by 106.56% and deflection by 115.58% compared to the reference beams. The unusual method of wood reinforcement presented in the article can be considered as innovative, characterized not only by a significant load capacity margin exceeding 141%, but also by simplicity of application.

Application of Transformed Cross-Section Method for Analytical Analysis of Laminated Veneer Lumber Beams Strengthened with Composite Materials

Due to the high cost of laboratory testing, many researchers are considering developing methods to predict the behavior of unreinforced and reinforced wood beams. This work aims to create either numerical or analytical models useful for extrapolating already conducted tests to other schemes/materials used as reinforcement. In the case of timber structures, due to the complexity of timber, this task is difficult. The first part of the article presents an analysis of the suitability of using a simplified mathematical model based on the equivalent cross-section method to describe the behavior of unreinforced and reinforced with carbon-fibre-reinforced polymer (CFRP) composite full-size laminated veneer lumber (LVL) beams. The theoretical results were compared with the results of conducted experimental tests. The scope of the analysis includes the estimation of modulus of rupture, bending stiffness, and determination of the neutral axis position. The equivalent cross-section method showed good agreement in determining the bending stiffness and neutral axis position of the strengthened sections. However, the suitability of using the equivalent cross-section method to estimate the load-carrying capacity of a cross-section reinforced with fiber composites still needs to be confirmed, which, according to the authors, is due to the differences between the assumed (linear) and actual (nonlinear) strain distribution in the compression zone. The second part uses the equivalent cross-section method to estimate the predicted bending stiffness of LVL beams strengthened with aramid-fibre-reinforced polymer (AFRP), glass-fibre-reinforced polymer (GFRP), and ultra-high modulus carbon-fibre-reinforced polymer (CFRP UHM) sheets. The proposed method can be used for preliminary evaluation of strengthening effectiveness of LVL beams.

Understanding the historic legacies of empire from the timbers left behind: Towards critical dendroprovenancing in the British North Atlantic

AbstractThe forests of British North America were integral to Britain's maritime empire. Many of these timbers exist today as wooden beams and flooring at historical dockyards and garrisons such as the Royal Naval Dockyard of Bermuda. In this paper, we investigate what timbers from this Dockyard can tell us about interconnections and empire‐building throughout the North Atlantic region. To do this we drew from approaches of critical physical geography, historical geography, and dendroprovenancing by using timber as a way to interrogate collaboratively the changes in—and connections across—socio‐ecological landscapes. We examined HM Customs records between 1825 and 1850 to determine the flow of timbers to Bermuda. We then sampled timbers from buildings constructed between 1825 and 1853 and analyzed them using isotopic and dendrochronological techniques to establish the probable location of origin of the timber samples. HM Customs records showed that prior to the 1840s, timbers primarily came from British North America, whereas post‐1840 timbers primarily came from the southeastern United States, with some still coming from Europe and British North America. To establish whether timber use by the Royal Navy and Royal Engineers matched the pattern in the customs documents, we looked to the dendrochronological records. Dendrochronologic evidence showed that military construction followed the same pattern, with buildings constructed pre‐1840 using material from British North America and buildings constructed post‐1840 using timbers sourced from the southeastern United States. Finally, using this information we explore some of the connections between regions, in terms of resource use, and the implications of those uses—for example, that the British Admiralty continued to benefit from the practices of slavery through the use of products produced from enslaved labour in other parts of the North Atlantic well after emancipation.

POSITION OF THE NEUTRAL LINE AND ITS EFFECT ON DETERMINING THE ACTUAL MECHANICAL CHARACTERISTICS OF WOOD UNDER TRANSVERSE BENDING

The analysis of the work of elements made of solid and glued wood under direct and oblique transverse bending with an increase in the level of short-term load was carried out. Coniferous wood, used in engineering structures, is an elastic-plastic anisotropic material for work both along and across the fibers. An exception is work on longitudinal tension. Within the limits from the beginning of loading and up to (0.9...0.95)% of the destructive wood works elastically, but in the future, as the loads increase, it also goes into the stage of nonlinear deformation. It has been established that many authors who conducted experimental and theoretical studies of the work of wooden beams indicate that the position of the neutral line of force in the cross section of the element under conditions of direct transverse bending at different levels of action of one-time loads changes its position. 108 The destruction of long wooden beams during transverse bending, due to the lower strength of wood in longitudinal compression compared to tension, begins in the compressed zone of the cross section with the formation of folds, which are often difficult to visually notice and record due to their instantaneous appearance and disappearance. in experimental studies. The final destruction of such beams takes place precisely in the stretched zone by breaking of the extreme fibers. Disproved theses on which the calculations of wooden structures, both from solid and glued wood for transverse bending, are based, which are carried out according to the current design standards of various countries using the limit state method with the prediction of the elastic work of wood from the beginning of loading to failure. It was established that the moment of resistance of the cross-section of a bending wooden element Wy can be determined only in the case when the force neutral line (plane) will pass only through the center of gravity of this section and when it is located in the middle of the beam at the height 2hх. The obtained results of the temporary resistance of wood in transverse bending, which are determined in the limit state using the moment of resistance of the cross section of the element Wy , are unreliable.

Особенности проектирования деревянных мостов автомобильных лесовозных дорог

The supply of the national economy with forest resources is directly related to transport accessibility, the condition and development of the road network of forest-rich territories. Construction requirements for year-round and seasonal new forest roads are 2.1 and 9.3 ths km per year, respectively. The situation is complicated by the transfer of transport facilities to new heavier live loads. The previously used design shapes of transport structures are outdated and require new engineering solutions. This is especially relevant for wooden bridge structures, which are of primary importance to forest road builders. The research subject is the wooden bridge girder superstructures with spans of 12–18 m undergoing increased road loads compared to the previous ones. The research aims is the development of modern designs of wooden beam superstructures based on the composite girders made of logs, board-bar-dowel-nail blocks and factory-made laminated blocks. The research includes: superstructures with composite girders of logs combined by combdowel joints, a method for calculating superstructures with composite girders, design of a 15-meter experimental superstructure containing composite log girders in joint operation with roadway reinforced concrete slab; new designs of 15–21-meter superstructures with board-bar-dowel-nail blocks A11 and NK-80 for live loads, design procedure and technology of block manufacturing, examples of designed and built bridges with the 15-meter superstructures; designs of multi-ribbed superstructures made of prefabricated transportable one-piece laminated sections containing laminated beams and a multilayer laminated timber slab. The proposed designes with composite girders of logs (beams) and board-nail blocks can be manufactured on the sites and yards of logging organizations using commonly used equipment, local qualified staff and materials. The cost parameters of permanent bridges built in the Omsk region with the use of these designs are 1.5–2 times lower than those of reinforced concrete analogues. The use of these designs will be effective in the pilot method of forestry development. The use of laminated superstructures is related to the modern phase of forest infrastructure development.

Stress-strain state of metal-wood crossbar of double-hinged frames

Objective the purpose of these studies is to choose the optimal design solution in the design of double-hinged wooden frames with a metal-wood crossbar, based on a comparative analysis of the stress-strain state of a metal-wood crossbar in the form of beams of various shapes, determined by the results of theoretical studies and numerical experiment.Method. Determination of the stress-strain state of metal-wood beams using theoretical studies and numerical experiment performed in the computer complex PC "LIRA".Result. Optimal design solutions of metal-wood crossbars of double-hinged frames in the form of reinforced beams of various shapes are proposed.Conclusion. The bearing capacity of double-hinged frames with a crossbar in the form of reinforced glued wood beams is on average 35 - 38% higher than the load bearing capacity with a crossbar in the form of un­reinforced glued wood beams.The use of metal-wood (reinforced) beams makes it possible to optimize the cross-section by reducing the cross-section height, thereby saving up to 40% on wood material.

The forced sound transmission of finite periodic plates using a variational approach

Many engineering structures consist of plates being periodically stiffened or loaded. Examples can be wooden joist floors, dry walls with wooden or metal beams, or metamaterials for increased sound insulation. Even though some of these structures are well known and thoroughly studied in the past, there lack prediction models that can handle both the finiteness and periodicity in a simple and accurate manner. In two previous attempts, the periodicity of the structure have been tried to be incorporated in a variational technique based on integral-differential equations of the fluid loaded plate, based on [J. Brunskog, JASA 132, 1482-1493, 2012]. These attempts have not worked well: they show a poor fit with measured data. In this paper, this issue is investigated again, and a different tactics is used to incorporate the periodicity, using space harmonics. In this way, the paper try to explain the previous misfit and improve the model.