Wood-based panels. Determination of characteristic values of mechanical properties and density

2015 ◽  
2019 ◽  
Vol 105 ◽  
pp. 76-84
Author(s):  
NADEŽDA LANGOVÁ ◽  
PAVOL JOŠČÁK

Mechanical Properties of Confirmat Screws Corner Joints Made of Native Wood and Wood-Based Composites. The aim of this investigation was to design and determine the mechanical properties of confirmat screws corner joints made of native wood and wood-based composites. The objective of the study was to ascertain the stiffness and load carrying capacity of joints that differed in the diameter and length of confirmat type screw, as well as in the kind of materials. The results include statistical processing of measured and calculated data, and evaluation of the influence of selected factors on mechanical properties. The results are applied to the calculation of the characteristic values of the properties and to the determination of the equations for their calculation for other values of the selected factors. The characteristic values are used for the evaluation of the joints according to the limit state method.


2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.


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