WOOD RESEARCH Volume 61, Number 5, 2016
Kristýna Vavrušová, David Mikolášek, Antonín Lokaj, Kristýna Klajmonová, Oldřich Sucharda, and Přemysl Pařenica

Determination of carrying capacity of steel-timber joints with steel rods glued-in parallel to grain

The issue of behavior and deformation of joints of wooden structures is an integral part of the design of timber structures in its entirety. In this article the attention is therefore devoted to joints of timber structures. For testing there were selected joints with glued-in steel rods. These joints are currently, due to the frequent requirement for invisibility of joints in structures, at the forefront of interest. The content of this paper is therefore testing of these joints and determination of their carrying capacity and describing the type of deformation under load. These tests were carried out on a pressure machine EU100 in the laboratory of the Faculty of Civil Engineering VSB-TU Ostrava. The results of the laboratory tests have been statistically evaluated and accompanied by the graphical records of deformation response to loading. Comparison of test carrying capacity results with values determined from calculation according to the current applicable European standard for design of timber structures and numerical modeling are also presented.

WOOD RESEARCH Volume 61, Number 5, 2016
Antonín Lokaj, Kristýna Klajmonová, David Mikolášek, and Kristýna Vavrušová

Behavior of round timber bolted joints under tension load

In the current European standards for the design of timber structures, the issue of timberto-timber joint type is addressed only to squared timber, which makes the pinpointing of the round timber bolted joints carrying capacity near-unfeasible due to the insufficient support in the current standards. There have been made series of tests of round timber joints in different inclinations tensile load to the grainand also the reference tests of squared timber joints to compare the behaviour of this type of joints. Mechanical behaviour of round and squared timber bolted joints were tested in the laboratory of the Faculty of Civil Engineering in Ostrava.This paper presents results of static tests in tension at an angle of 0, 90 and 60° to the grain of squared and round timber bolted joints. Carrying capacity was determined according to the applicable standards and theories of fracture mechanics. Round timber joints were also numerically simulated. The test results of numerical models were then compared with the results of laboratory tests and theoretical calculations.

WOOD RESEARCH Volume 61, Number 4, 2016
Kristýna Vavrušová, Antonín Lokaj, David Mikolášek, Roman Fojtík, and Libor Žídek

Longitudinal glued joints of timber beams and the inf luence of quality manufacturing onto their carrying capacity

The content of this article is to analyse destructive testing results of longitudinal solid wood joints of structural size beams with internal and external glued wood-based panels (plywood) stressed in bending, which was mostly focused on simulating the effect of the glued line thickness (1 and 3 mm) and the influence of contact surfaces of longitudinally connected elements when bending loads. The aim of this article is to compare the carrying capacity and the joint real behaviour under load with values obtained using numerical modelling and calculation according to valid standards.

WOOD RESEARCH Volume 61, Number 3, 2016
Vassilios Vassiliou, Ioannis Barboutis, and Vasiliki Kamperidou

Strength of corner and middle joints of upholstered furniture frames constructed with black locust and beech wood

Great interest is attracted lately in the utilization of Black locust (Robinia pseudoacacia L.) timber large quantities that are expected to be harvested and enter the market next years, since this species was included in the proposed and financed species for cultivation by the European Union. This study was carried out to evaluate the strength of the two most frequent joints in the upholstered furniture frames, constructed with black locust, using also beech wood (Fagus sylvatica L.) for comparative reason. In the specific research, the joints of mortise and tenon and double dowel were selected to be used and were constructed both in corner and middle joints, using two adhesives (PVAc and PUR). Bending moment capacity of the joint specimens was investigated, as well as the coefficient of elasticity of each joint.