scholarly journals STRUCTURAL SOLUTION AND METHOD OF CALCULATION OF GLUED LAMINATED TIMBER BEAM AND COLUMN JOINTS

2020 ◽  
Vol 4 (157) ◽  
pp. 12-17
Author(s):  
S. Shekhorkina ◽  
M. Savytskyi ◽  
T. Kovtun-Gorbachova
Keyword(s):  
Bearing Capacity ◽  
Current Trend ◽  
Bending Moment ◽  
Timber Beam ◽  
Load Bearing Capacity ◽  
Bolted Connection ◽  
Load Bearing ◽  
Method Of Calculation ◽  
Support Reaction ◽  
Glued Laminated Timber

The current trend in the construction industry is the development of projects of multi-storey buildings with a hybrid structural system using mainly timber load-bearing elements. The joints of load-bearing elements are criti-cal points of the frame with glued timber structures in terms of ensuring the load-bearing capacity and servicea-bility of the entire system. Existing publications in this area are mainly aimed at theoretical and experimental as-sessment of the stress-strain state of joints, while information on the construction of components for multi-storey buildings and recommendations for their design is extremely insufficient. The article presents structural solutions of the joints of glued laminated timber columns and beams, namely, hinged, which takes and transmits to the col-umn the support reaction of the beam, and rigid, which in addition to the support reaction takes the bending mo-ment. The support reaction from the beam to the column is transferred through a bolted connection and a T-shaped welded metal element. The bending moment is taken by two angles, which are fixed to the beam and welded to a vertical plate. Criteria of conformity of the proposed joints to load-bearing capacity requirements are pro-posed. The load-bearing capacity of the joint under the action of the support shear force is determined by the shear strength of the bolts in the column; the embedment strength of the metal of the T-shaped plate in the hole and bearing capacity of the bolted connection in the timber element. The action of the support bending moment requires the strength of the angles fastening to the beam and wood in the area of the bolts installation. A detailed algorithm for calculating the proposed design solutions in accordance with the requirements of the design stand-ards has been developed. Keywords: joint, glued laminated timber, beam, column, bearing capacity.

Load-bearing capacity and characteristic forms of destruction of furniture joints made with rastex 15 and P-10 clamex fasteners

2019 ◽  
Vol 106 ◽  
pp. 38-48
Author(s):  
Maciej Sydor ◽  
PIOTR POHL
Keyword(s):  
Bearing Capacity ◽  
Load Capacity ◽  
Bending Moment ◽  
Shear Forces ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Angular Deflection ◽  
Maximal Load ◽  
Rigidity Coefficient ◽  
The Relationship

Load-bearing capacity and characteristic forms of destruction of furniture joints made with rastex 15 and P-10 clamex fasteners. The study tested the relationship between the load and angular deflection in furniture joints. The tests were carried out for two types of fasteners and five types of materials: chipboard, MDF, hardwood plywood, glued pine boards and glued oak boards. The furniture joint samples contained two fasteners preloaded only with a bending moment (without application of shear forces). The results were converted per single fastener specifying: its maximal load capacity, 50 mrad (2.9°) limit deflection and rigidity coefficient. It was found that rigidity is a better structural property of the tested joint types than their load capacity. As far as rigidity is concerned, the most durable is the combination of oak glued board – rastex 15 fastener (13.2 Nm bending moment per fastener), while the least durable combination is chipboard – clamex P-10 fastener (4.8 Nm bending moment per fastener). Photographic documentation of damaged furniture joint samples was prepared and analysed. In case of chipboard and MDF combinations (where the load is determined by the combined material), the combined boards suffer a disastrous damage, while in combinations of plywood boards and pine or oak glued boards, (where the capacity is determined by the fastener), both clamex P10 and rastex 15 fasteners are damaged.

scholarly journals EXPERIMENTAL INVESTIGATION OF LOAD-BEARING CAPACITY AND DEFLECTIONS OF FULL-SCALE GLUED LAMINATED TIMBER BEAMS

2020 ◽  
Vol 2 (61) ◽  
pp. 5-11
Author(s):  
S. Shekhorkina ◽  
◽  
К. Shliakhov ◽  
А. Sopilniak ◽  
◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Strength Class ◽  
Failure Load ◽  
Timber Structures ◽  
Load Bearing Capacity ◽  
Concentrated Load ◽  
Load Bearing ◽  
Glued Laminated Timber ◽  
Deformation Properties ◽  
Timber Beams

With the transition to the design of timber structures in accordance with European standards, problems arise in assessment of the load-bearing capacity of glued timber structures that are caused by insufficient amount of data about the physical, mechanical and deformation properties of glued timber, which is produced in Ukraine. The aim of the work was to determine the load bearing capacity in bending and deflection of a glued timber beam under the action of a concentrated load in the middle of the span. Two glued laminated timber beams were used in the experiment. Both beams were made using lumber from pine wood and a moisture-curing onecomponent polyurethane adhesive Kleiberit PUR 510 FiberBond. The beams have the dimensions of the cross-section: width of 120 mm and height of 180 mm. The length of the beams was 9880 mm. Each beam consisted of 9 layers of 20 mm thick lamellas glued together. Considering the absence of the data on the strength class of the beam material, the theoretical load bearing capacity and deflection were determined according to the characteristics of the GL24h class (minimum strength class), and amounted to 722 kgf and 19.1 cm, respectively. As a result of the tests, the failure load and the deflection of the beams were determined, and the dependences of the deflection on the load were obtained. The actual deflection of the beams determined was 251 mm and 275 mm, which is 1.31 and 1.44 times higher than the predicted deflection. Accordingly, the failure load determined experimentally is 1.96 and 2.03 times higher than the theoretical value. During the tests, the features of the deformation and the nature of the destruction of the beams were investigated. Wherein, the determining factor was the presence of defects in timber and lamellas joints along the length in the most stressed layers. Based on the data obtained, recommendations on manufacturing aimed at the increasing the bending strength of glued laminated timber beams are given. The results obtained will be further used in the development of structural solutions for hybrid timber-concrete floors.

scholarly journals An Analysis of the Load-Bearing Capacity of Timber-Concrete Composite Beams with Profiled Sheeting

2017 ◽  
Vol 27 (4) ◽  
pp. 143-156 ◽  
Author(s):  
Maciej Szumigała ◽  
Ewa Szumigała ◽  
Łukasz Polus
Keyword(s):  
Numerical Analysis ◽  
Bearing Capacity ◽  
Concrete Slab ◽  
Composite Beams ◽  
Concrete Slabs ◽  
Timber Beam ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Shear Connectors ◽  
Timber Beams

Abstract This paper presents an analysis of timber-concrete composite beams. Said composite beams consist of rectangular timber beams and concrete slabs poured into the steel sheeting. The concrete slab is connected with the timber beam using special shear connectors. The authors of this article are trying to patent these connectors. The article contains results from a numerical analysis. It is demonstrated that the type of steel sheeting used as a lost formwork has an influence on the load-bearing capacity and stiffness of the timber-concrete composite beams.

scholarly journals The Efficiency of Utilisation of High-strength Steel in Tubular Profiles

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1193 ◽  
Author(s):  
Ieva Misiūnaitė ◽  
Viktor Gribniak ◽  
Arvydas Rimkus ◽  
Ronaldas Jakubovskis
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
High Strength Steel ◽  
Current Trend ◽  
Weight Ratio ◽  
High Strength ◽  
Beam Specimen ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Structural Applications

The use of high-strength steel (HSS) is a current trend of the construction industry. Tubular profiles are widely used in various structural applications because of their high stiffness-to-weight ratio, exceptional resistance to torsion, and aesthetic appearance. However, the increase of the strength for the same elastic modulus of the material and geometry of tubular profiles is often not proportional to the rise of the load-bearing capacity of the structural element. The obtained experimental results support the above inference. The study was based on the flexural test results of two groups of HSS and normal-strength steel (NSS) tubular specimens with a 100 × 100 × 4 mm (height × width × thickness) cross-section. Numerical (finite element) simulation results demonstrated that the shape of the cross-section influenced the efficiency of utilisation of HSS. The relationship between the relative increase of the load-bearing capacity of the beam specimen and the corresponding change of the steel strength determined the utilisation efficiency.

Experiments on Wall Panels with One-Sided Board Sheathing for Timber Structures

2017 ◽  
Vol 1144 ◽  
pp. 3-8
Author(s):  
Jiří Celler ◽  
Jakub Dolejs ◽  
Vera Hlavata
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Timber Structures ◽  
Bearing Material ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Glued Laminated Timber ◽  
Wall Panels ◽  
The Stability ◽  
Shaped Cross Section

Timber elements with an I-shaped cross-section are used as supporting elements in wall, ceiling and roof panels of light timber frames. The reinforcement of the panel (I-stud) is provided by means of glued timber composite I-shaped element consisting of a web made of a wood-based desk embedded into flanges of solid or glued laminated timber. The stability of the wall panels is usually ensured by sided board sheathing, which prevents buckling of studs in the plane of the wall or their twist. Walls with one-side board sheathing are used for some types of modern timber structures and their load bearing capacity is determined for situation when one-side sheathing burns down during fire or sheathing is not made of a load-bearing material.

scholarly journals The mechanical effects of bulges developed around bark-included branch junctions of hazel (Corylus avellana L.) and other trees

Trees ◽  
2021 ◽  
Author(s):  
Duncan Slater
Keyword(s):  
Bearing Capacity ◽  
Compensatory Growth ◽  
Secondary Growth ◽  
Bending Moment ◽  
Tensile Tests ◽  
Corylus Avellana ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Analysis Of The Images ◽  
Corylus Avellana L

Abstract Key message Large bulges formed around bark-included branch junctions can be conceived of as ‘compensatory growth’. Despite Claus Mattheck’s hypothesis that ‘the larger the bulges, the more likely the branch junction is to fail’, this study identifies that the extent of the defect inside such bulges is key information in predicting the junction’s load-bearing capacity. Abstract A currently prevalent rule in European arboriculture is that if a bark-included branch junction in a tree is associated with a large bulge in-line with the plane of the included bark then it is more likely to fail than if there is a smaller bulge or the absence of bulging. This rule for arborists originates from an initial suggestion with no associated data and is not logically consistent with recent research into the effects of natural bracing in trees, nor guidance provided by the International Society of Arboriculture. This also raises the question of how to correctly interpret the function of these bulges formed at bark-included junctions: either as secondary growth that has been pushed to the side by internal growth pressures, or as compensatory growth developing around a weakened component. To test the veracity of this rule, 117 branch junctions of common hazel (Corylus avellana L.) were subjected to tensile tests, comprising of controls with no bark included within them and bark-included specimens exhibiting a range of bulge sizes. In addition, photographs from the failure of 110 bark-included junctions were categorized to assess the frequency of failed specimens with different degrees of bulging. The results of the mechanical testing identified three significant factors that affected the maximal bending moment of these branch junctions: their categorized morphology, the diameter ratio of the branch junction and the width of the included bark at the apex of the junction. Overall, and in each category of branch junction tested, the extent of bulging was not found to be a significant predictor of the junctions’ maximal bending moment. This finding was reinforced by the analysis of the images of bark inclusion failure where the most frequent bark inclusions to fail were those associated with little to no bulging. Both findings identify that the bulging would be better interpreted as compensatory growth. This study highlights the need for further research on the load-bearing capacity of bark-included branch junctions to better inform arborists and tree managers as substantial variations in their biomechanical performance have not yet been elucidated.

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