scholarly journals Analysis of the load bearing capacity of the connection with the use of self-drilling dowels in various models of elastic failure

Author(s):  
A. G. Chernykh ◽  
◽  
Quoc Phong Tran ◽  

Currently, wooden structures characterized with high strength, low deformability and good aesthetics are being increasingly used in some areas of construction. Connections with multiple steel plates are very effective for wooden frames and trusses. In order to provide optimal connections, it is necessary to establish the relationship between the connection parameters and the load-bearing capacity of the structure. However, the technical regulations do not provide calculation methods specifically for this type of connection. There have been carried out a research and development of methods for calculating connections, an analysis of the self-drilling dowels` performance, and the factors affecting the load bearing capacity according to Eurocode 5 have been specified. The results obtained have been compared with other various research methods` results, there are offered authors` recommendations on the application of the standard in Russia.

Author(s):  
Quoc Phong Tran ◽  

The article presents the results of calculation of the load-bearing capacity of connections of LVL structures under tension using cylindrical dowels in trusses and frames. The description of calculation schemes for determining the load-bearing capacity of connections with different location and sizes of steel plates in the connection is given. The influence of steel plate placement on the distribution of forces in the cross-section of samples is investigated. Based on the results of analytical and experimental studies, the load-bearing capacity of dowels during bending is considered, as well as the mechanism of wooden structures` fracture during chipping. A comparative analysis of the effectiveness of different schemes of dowel connections with three steel plates under tension is carried out.


2019 ◽  
Vol 97 ◽  
pp. 04059 ◽  
Author(s):  
Alexey Dem’yanov ◽  
Vladymir Kolchunov ◽  
Igor Iakovenko ◽  
Anastasiya Kozarez

It is presented the formulation and solution of the load bearing capacity of statically indeterminable systems “reinforced concrete beam – deformable base” by spatial cross-sections under force and deformation effects. The solution of problem is currently practically absent in general form. It has been established the relationship between stresses and strains of compressed concrete and tensile reinforcement in the form of diagrams. The properties of the base model connections are described based on a variable rigidity coefficient. It is constructed a system of n equations in the form of the initial parameters method with using the modules of the force (strain) action vector. The equations of state are the dependences that establish the relationship between displacements which are acting on the beam with load. Constants of integration are determined by recurrent formulas. It makes possible to obtain the method of initial parameters in the expanded form and, consequently, the method of displacements for calculating statically indefinable systems. The values of the effort obtained could be used to determine the curvature and rigidity of the sections in this way. It is necessary not to set the vector modulusP, the deformation is set in any section (the module is considered as an unknown) during the problem is solving. This allows us to obtain an unambiguous solution even in the case when the dependence M–χ has a downward section, i.e one value of moment can correspond to two values of curvature.


2016 ◽  
Vol 711 ◽  
pp. 564-571 ◽  
Author(s):  
Thomas Gernay

The use of high strength concrete (HSC) in multi-story buildings has become increasingly popular. Selection of HSC over normal strength concrete (NSC) allows for reducing the dimensions of the columns sections. However, this reduction has consequences on the structural performance in case of fire, as smaller cross sections lead to faster temperature increase in the section core. Besides, HSC experiences higher rates of strength loss with temperature and a higher susceptibility to spalling than NSC. The fire performance of a column can thus be affected by selecting HSC over NSC. This research performs a comparison of the fire performance of HSC and NSC columns, based on numerical simulations by finite element method. The thermal and structural analyses of the columns are conducted with the software SAFIR®. The variation of concrete strength with temperature for the different concrete classes is adopted from Eurocode. Different configurations are compared, including columns with the same load bearing capacity and columns with the same cross section. The relative loss of load bearing capacity during the fire is found to be more pronounced for HSC columns than for NSC columns. The impact on fire resistance rating is discussed. These results suggest that consideration of fire loading limits the opportunities for use of HSC, especially when the objective is to reduce the dimensions of the columns sections.


2019 ◽  
Vol 106 ◽  
pp. 38-48
Author(s):  
Maciej Sydor ◽  
PIOTR POHL

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.


2019 ◽  
Vol 29 (4) ◽  
pp. 141-148 ◽  
Author(s):  
Krzysztof Wierzbicki ◽  
Maciej Szumigała

Abstract The article analyses the method of enhancing a steel beam by adding additional steel members like ribs. They are rigidly connected with both flanges in a plane parallel to the web. That plates reduces warping during in-plane bending of steel beam under lateral-torsional bucking. Different thicknesses of steel plates used as ribs and different cross-sections were taken into account. Calculations were conducted using FEM and ABAQUS CAE environment. The outcomes were compared with ones from previous studies which concerned an influence of endplates on load-bearing capacity of an I-beam.


2018 ◽  
Vol 15 (5) ◽  
pp. 760-773 ◽  
Author(s):  
V. A. Utkin ◽  
P. N. Kobzev ◽  
E. G. Shatunova

Introduction. Experience in the design and construction of beam structures of wooden bridges with composite girders indicates the possibility of increasing the bearing capacity and the length of the overlapped spans.Materials and methods. The most rational load-bearing elements of composite girders can serve as the logs edged on two edges with the diameter of 28 to 32 cm with the maximum use of the most durable layers of sapwood and dowel connections of steel plates with blind cylindrical nags.Results. In contrast to the compounds of composite girders on lamellar nails, the proposed connection greatly simplifies the process of making the composite girders. Such connection also allows using the logging along the length, combining into three or four tiers and increasing the length of the span.Discussion and conclusion. The proposed solutions increase the load-bearing capacity of composite girders and allow them to be used in the structures of wooden bridges under modern automotive loads. Moreover, the calculation method of composite girders on the basis of the method of forces and discrete placement in the beams between the logs of concentrated elastic-datum shear bonds is developed.


The focus of this analysis is the review of steel plate strengthened RC beams using Single row and Stagger row bolt arrangements and to compare the bonding behaviour of different bolts arrangement under flexure. Also, to investigate the behaviour, load bearing capacity and the deflection for control and steel plate bonded beams. This research is constrained by FEM analysis utilizing ANSYS to the actions of standard RC Beam and RC beam steel plate associated.


Author(s):  
Anne K. Kawohl ◽  
Jörg Lange

Prior investigations of the load bearing capacity of bolts during fire have shown differing behaviour between bolts that were loaded by shear or by tensile loads. The interaction of the two loads has not yet been examined under fire conditions. This paper describes a preliminary test series on the post-fire performance of high-strength bolts of the property class 10.9 under combined tension and shear. The results show that how the bolt is loaded influences the load bearing capacity. It is assumed that this is also true at elevated temperatures. Further, atest set-up for experiments at elevated temperatures and a more detailed test series on the post-fire performance under combined tension and shear is presented.


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