Round Timber Bolted Joints Reinforcement Methods

2014 ◽  
Vol 1020 ◽  
pp. 351-355 ◽  
Author(s):  
Kristýna Klajmonová ◽  
Antonín Lokaj

This paper presents the results of static tests of non-reinforced and reinforced round timber bolted joints with slotted-in steel plates. In this article, a new approach to the reinforcement of round timber bolted joints is presented. Based on results from tension tests of timber bolted joint samples, reinforcement methods were proposed. From these, modified washers and boost with screws were chosen for further tension testing. Results were compared to unreinforced ones and rate of improvement established.

2013 ◽  
Vol 838-841 ◽  
pp. 629-633 ◽  
Author(s):  
Kristýna Klajmonová ◽  
Antonín Lokaj

This paper presents the results of static tests of round timber bolted joints with inserted steel plates. All round timber joints static tests in tension were carried out on pressure machine EU 100 in laboratory of the Faculty of Civil Engineering VŠB-TU Ostrava. At first, timber specimens were tested without reinforcement. Based on these results, mechanical reinforcement methods were proposed: using modified washers and boost with screws. These samples were also tested. Rate of improvement in tensile strength was established for used reinforcement method.


2014 ◽  
Vol 1082 ◽  
pp. 359-364
Author(s):  
Kristýna Klajmonová ◽  
Antonín Lokaj

In this article the results of round timber bolted joints with inserted steel plates tests are presented. First, unreinforced round timber specimens were tested. Mechanical reinforcement by using modified washers, steel bands, BOVA plates and boost with screws of round timber specimens based on test result was then proposed. Reinforced specimens of various densities were then tested and rate of improvement in tensile strength was established for each of five proposed reinforcement methods. Tests were carried out on EU100 pressure machine in Faculty of Civil Engineering of VŠB-TUO Ostrava.


2014 ◽  
Vol 893 ◽  
pp. 702-706 ◽  
Author(s):  
Antonín Lokaj ◽  
Kristýna Klajmonová ◽  
Vit Křivý

Aim of this article is in presentation of results of static and cyclic tests of round timber bolted joints with inserted steel plates. At first, timber specimens were tested without reinforcement. Based on static tests results, mechanical reinforcement methods were proposed and tested: using modified washers and boost with screws. Rate of improvement in tensile strength was established for used reinforcement method. Static tests in tension were carried out on pressure machine EU 100 in laboratory of the Faculty of Civil Engineering VŠB-TU Ostrava. Round timber joints multi cyclical dynamic (fatigue) tests in tension were made in laboratory of ITAM AS CR Prague and in TRI Žilina.


Author(s):  
Antonín Lokaj ◽  
Kristýna Klajmonová

Abstract Aim of this article is in presentation of results of static tests of round timber bolted connections with steel plates. Round timber connections tests in tension were made on pressure machine EU100 in laboratory of the Faculty of Civil Engineering VSB-TU Ostrava. Results of laboratory tests have been statistically evaluated and completed by graphical records of deformation response on loading.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1327-1330
Author(s):  
Kristýna Klajmonová ◽  
Antonín Lokaj

This paper presents the results of static tests of non-reinforced round timber bolted joints with slotted-in steel plates loaded perpendicular to the grain. This type of joints loading is particularly widespread in truss structures. Round timber test samples series were prepared to validate the behavior of a joint loaded in tension perpendicular to the grain. The joints samples were experimentally tested in the laboratory of the Faculty of Civil Engineering VŠB TU Ostrava. The test results were compared with the calculated load-carrying capacity of joints by Johansen’s yielding theory.


2014 ◽  
Vol 627 ◽  
pp. 29-32
Author(s):  
Antonín Lokaj

Aim of this paper is in presentation of results of static and dynamic tests of round timber bolted connections with slotted – in steel plates. Round timber joints static tests in tension were made on pressure machine. Round timber joints multicyclic (fatigue) tests in tension were made on pulsator. Results of laboratory tests have been statistically evaluated and completed by graphical records of deformation response on loading. Samples of round timber bolt connections with slotted - in steel plates were tested for carrying capacity and deformation of a single tension – up to the failure of connection.


2014 ◽  
Vol 566 ◽  
pp. 232-237
Author(s):  
H. Ambarita ◽  
M. Daimaruya ◽  
H. Fujiki

The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of a lap bolted joint used in the suspension parts of a car body. For the accurate prediction of crash characteristics of car bodies by computer-aided engineering (CAE), it is also necessary to examine the behaviour and fracture of the jointed steel plates subjected to impact loads. Although the actual impact fracture of jointed steel plates of a lap bolted joint in cars is complicated, for simplifying it is classified into the shear fracture and the extractive fracture of jointed steel plates. Three kinds of steel plates, i.e., common steel with the tensile strength of 270 MPa and two high tensile strength steels with the tensile strength of 440 and 590 MPa level used for vehicles, are examined. In the impact shear test, the specimens are made of two plates and jointed by a bolt, and in the impact extractive test the specimens are made of a plate and drilled in the centre for a bolt. The impact shear test of jointed steel plates of lap bolted joints is performed using a modified split Hopkinson bar apparatus, while the impact extractive one is performed using one-bar method. Numerical simulations by a FEM code LS-DYNA are also carried out in order to understand the mechanism of shearing and extractive fractures process of jointed steel plates. The obtained results suggest that a stress-based fracture criterion may be developed for the impact shearing and extractive fractures of jointed steel plates of lap bolted joints used in a car body.


2014 ◽  
Vol 668-669 ◽  
pp. 115-118
Author(s):  
Xi Wang Wang ◽  
Xiao Yang Li ◽  
Xiao Guang Wang ◽  
Lin Lin Zhang

Bolt load in a bolted connection directly influence the safety of a design in regard to both static and fatigue loading as well as in the prevention of separation in the connection. When the separating force is applied off the bolt center, although the materials for the bolted joint remain in the linear elastic range, the interface contact area between the clamped plates is sensitive to both the magnitude and the location of the separating force. This often causes nonlinear variation of the bolt load, the deformation etc. An analytical model is proposed to obtain the expression for the nonlinear bolt load under a separating service load. Finite element modeling is used for evaluating the accuracy of the proposed model.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5525
Author(s):  
Antonin Lokaj ◽  
Pavel Dobes ◽  
Oldrich Sucharda

This article presents the results of static tests on bolted connections in squared and round timber with inserted steel plates. The experiment evaluates structural timber connections with different distances between the fastener and the loaded end at different moisture contents. Specimens were loaded by tension parallel to the grain and load–deformation diagrams were recorded. Fifty-six specimens with three different distances between the fastener and the loaded end, at different moisture contents, were tested. The results were statistically evaluated using regression analysis, complemented with load–deformation curves, and compared with calculations according to the valid standard for design of timber structures. A decrease in the evaluated load-carrying capacity with increasing moisture content was confirmed experimentally. A slight increase in the evaluated load-carrying capacity with increasing fastener distance from the loaded end was found.


2014 ◽  
Vol 1020 ◽  
pp. 199-203
Author(s):  
Antonín Lokaj ◽  
Kristýna Klajmonová

Aim of this article is in presentation of results of dynamic tests of reinforced round timber bolted connections with slotted – in steel plates. Multicyclic dynamic (fatigue) tests in tension were made with round timber joints on pulsator. Results of laboratory tests have been statistically evaluated and completed with graphical records of carrying capacity of connections in tension corresponding to number of loading cycles.


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