scholarly journals DEVELOPMENT AND IMPROVEMENT OF BEAM STRUCTURES ON THE BASIS OF COMPOSITE LOGS’ GIRDERS

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.

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.


2012 ◽  
Vol 446-449 ◽  
pp. 1182-1185
Author(s):  
Wen Liang Qiu ◽  
Cai Liang Huang ◽  
Zhao Yi Chen

Because the multi-box girder bridge has many advantages, such as large torsion rigidity, large load-bearing capacity, stability, fine appearance, good applicability and convenient construction, it is widely used in China. But for the defection existing in design and construction, many box girders have serious diseases. Aiming at the diseases of a viaduct bridge, the causes of diseases are analyzed and the enforcement method is proposed in this paper. The study shows that, though the box girders have large torsion rigidity, the diaphragms are designed necessarily to enhance the transversal connection between the box girders, to make them bear the loads together, to reduce their stresses and deformation, and to reduce the stresses of deck too.


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.


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.


2019 ◽  
Vol 92 ◽  
pp. 13007
Author(s):  
Borana Kullolli ◽  
Pablo Cuéllar ◽  
Matthias Baeßler ◽  
Hans Henning Stutz

The structural performance of many geotechnical systems (e.g. axially-loaded pile foundations), depends on the shearing resistance at the soil interface, which may govern the load bearing capacity of the foundation. Experimental investigations have shown that this interaction is mainly localised within a narrow shear band next to the structure. Under cyclic loading, a contraction of the soil at the interface may arise (net volume loss), possibly leading to a stress relaxation and thus to a reduction of the load bearing capacity (the so-called friction fatigue). Based on the constitutive similarities between soil continua and interfaces, we propose here the adaption of a Generalized Plasticity model for sandy soils for the numerical analysis of interface problems. In this contribution, the results of an experimental campaign for the parameter calibration of the constitutive model are presented. The tests have been conducted with a ring shear device involving different normal stresses, roughness of the steel plates as well as cyclic loading. The new modelling approach shows promising results and has the additional practical advantage that the interface zone and the soil continuum can both be described with the same constitutive model in general boundary value problems.


Author(s):  
Quoc Phong Tran ◽  

The load-bearing capacity of the dowel connections of wooden structures is determined by two limiting states, namely, by the failure of wood (crumpling) or deformation of steel dowel (bending). Both failure models are plastic. In some cases, brittle failure is possible, which will determine the load-bearing capacity of the connection. However, the regulations in the Russian Federation do not consider the brittle failure of dowel connections because this type of failure is excluded by the rules for placing dowels. Appendix A of Eurocode 5 includes types of brittle failure caused by chipping of a block or slipping of wood in connection. In [10, 11], the authors consider various fracture models for connections with large-diameter dowels (over 12 mm). In the present study, the author evaluates and classifies calculation models for brittle failure in connections of wooden structures using self-drilling dowels of small diameter (less than 12 mm), which are not presented in the Eurocode 5 and SP 64.13330.2017 standards. Solutions are proposed for reducing the probability of brittle failure propagation in such connections.


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.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Hongmeng Huang ◽  
Lu Cui ◽  
Wei Lu

The thickness, reinforcement, and concrete strength grade of railway caps in China are generally determined according to the force, yet the method for calculating the force is unclear. To date, there is no desirable calculation method for analyzing the caps. Based on the fifteen-pile thick cap of mixed passenger and freight railway, the influencing factors on cap bearing capacity were analyzed using finite element method (FEM). The variations of load-bearing capacity and mechanical behavior of thick cap were characterized by introducing rigid angle α. Results indicated that ultimate load-bearing value of the cap increased linearly with the increase of concrete strength grade, and an increasing load-bearing capacity of the reinforcement distributed in the pile diameter range was larger than that of the uniform reinforcement; when the reinforcement ratio was 0.15%, it increased by 9.3%. The cap showed punching failure when α < 45°. The reaction force at each pile top under vertical load was not equal; thereby, the cap was not absolutely rigid. The principal compressive stress trajectories in the concrete were distributed in the range of connecting the pile and the outer edge of the pier, and the effective tensile stresses in the reinforcement were mainly distributed in the diameter range of pile and pile connection, which is in accord with the stress mode of the ordinary spatial truss model. Based on this, a spatial truss model applicable to the design of railway caps is proposed, and a method for calculating reaction force at pile top and formulas for calculating the bearing capacity of strut and tie were presented. The feasibility of the proposed method was also verified by comparison with FEM results.


2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdelkadir Fellouh ◽  
Abdelkader Bougara ◽  
Paulo Piloto ◽  
Nourredine Benlakehal

PurposeInvestigate the fire performance of eccentrically loaded concrete partially encased column (PEC), using the advanced calculation method (ANSYS 18.2, 2017) and the simple calculation method in Annex G of Eurocode 4 (EN 1994-1-2, 2005). This work examines the influence of a range of parameters on fire behaviour of the composite column including: eccentricity loading, slenderness, reinforcement, fire rating and fire scenario. In this study, ISO-834 (ISO834-1, 1999) was used as fire source.Design/methodology/approachCurrently, different methods of analysis used to assess the thermal behaviour of composite column exposed to fire. Analytical method named simplified calculation methods defined in European standard and numerical simulations named advanced calculation models are treated in this paper.FindingsThe load-bearing capacity of the composite column becomes very weak in the presence of the fire accident and eccentric loading, this recommends to avoid as much as possible eccentric loading during the design of construction building. The reinforcement has a slight influence on the temperature evolution; moreover, the reinforcement has a great contribution on the load capacity, especially in combined compression and bending. When only the two concrete sides are exposed to fire, the partially encased composite column presents a high load-bearing capacity value.Originality/valueThe use of a three-dimensional numerical model (ANSYS) allowed to describe easily the thermal behaviour of PEC columns under eccentric loading with the regard to the analytical method, which is based on three complex steps. In this study, the presence of the load eccentricity has found to have more effect on the load-bearing capacity than the slenderness of the composite column. Introducing a load eccentricity on the top of the column may have the same a reducing effect on the load-bearing capacity as the fire.


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