APPLICATION OF SINGULAR VALUE DECOMPOSITION FOR QUALITATIVE ANALYSIS OF TRUSS AND TENSEGRITY STRUCTURES
Autor
Wojciech Gilewski, Joanna Kłosowska, Paulina Obara
Pages
3–20
Keywords
singular value decomposition, truss, tensegrity
Abstract
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The present paper is dedicated to the application of singular value decomposition (SVD) of extension matrix to the qualitative analysis of truss and tensegrity structures. The decomposition allow to define infinitesimal mechanisms as well as self-stress states of the truss. It can help to recognize if the truss is in tensegrity configuration. Theoretical considerations are illustrated on several examples.
THE STABILITY OF AVERAGE THICKNESS ANISOTROPIC CYLINDRICAL SHELLS UNDER AXIAL COMPRESSION
Autor
Wołodymyr Tracz, Mikołaj Chorużyj
Pages
21–34
Keywords
Timoshenko theory, stability of shells, anisothropy
Abstract
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Based on the Timoshenko theory the approach is presented for calculation of the stability of anisotropic cylindrical shell due to the geometrical prebuckling non-linear stress-strain state. The relevant properties of the coating material are symmetrical according a plane which can coincide with the central surface. Numerical study was performed using the method of discrete orthogonalization. A graph is illustrating the effect of the angle of layering of the fiber composite for the critical stress to axial compression.
GABION WALL TESTING DURING THE FORCED OVERLOADING IN THE GEOTECHNICAL CENTRIFUGE
Autor
Edyta E. Malinowska
Pages
35–43
Keywords
gabion wall, geotechnical centrifuge, physical and mechanical parameters
Abstract
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The paper is referring to the geotechnical centrifuge modelling that is used to prove the gabion facing wall stability. The gabion reinforcement wall is 15.3 meters tall and 17 meters length. The centrifuge model was speed up to 50 g and 75 g, and hadn’t failure. The test results show that the largest settlements under 75 g speed was about 2.25 meters vertically and mainly in the gabion wall and just behind the gabion section. The largest settlements under 50 g speed was about 1.07 meter vertically and 1.8 meters horizontally. The value of the settlement increases with the shortness of the reinforcement. The value of the settlement decreases with the reduction of the gabion spacing in the wall facing. Reinforced gabion retaining wall can work safely. Nevertheless, mechanical and deformation behaviors need to be studied for wide applying in a practical engineering.
This work contains proposition of the empirical relationship based on a standard laboratory tests for the estimation the initial shear modulus (GMax) for cohesive soils. The analysis of the results of measurements shear wave velocity from bender elements tests was presented.
In this paper the physical and mechanical properties of reactive materials are presented. Reactive materials are build the reactive zone of permeable reactive barrier (PRB) used for the remediation of contaminated groundwater. Up till now the criteria for selecting a reactive material for PRB are included only the remediation and hydraulic properties of materials. However, physical and mechanical properties of these materials have to be taking into account due to the engineering aspect of design parameters of PRB in groundwater, as well as their stability and longevity. The paper presents the results of shear strength and compressibility properties of selected reactive materials that may be considered during the selection of construction technology of barrier and to verify the ultimate limit states during the design stage of PBR.
EFFECT OF ADDITION OF POLYSTYRENE GRANULES ON SELECTED PHYSICAL AND MECHANICAL PROPERTIES OF CONCRETE
Autor
Krzysztof Wiśniewski, Gabriela Rutkowska, Kamil Szczęsny
Pages
67–77
Keywords
concrete, concrete mix, polystyrene granules
Abstract
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The aim of this study is to compare the selected physical and mechanical properties of concrete mix and hardened concrete C16/20, depending on the percentage of polystyrene granules. This work contains presentation of literature which show the characteristics and properties of concrete mix and hardened concrete. In addition, this work presents an analysis of the results of examination of: test the consistency of concrete mix, compressive strength of concrete, tensile strength of concrete, and the depth of penetration of water under pressure and water absorption.
ANALYSIS OF ENERGY CONSUMPTION AND THE COST OF HEATING IN SINGLE-FAMILY BUILDING IN THE LIGHT OF CHANGING LEGAL REQUIREMENTS
Autor
Piotr Wichowski, Stanisław Banaszek
Pages
79–92
Keywords
thermal transmittance, thermal load, seasonal demand for heat, energy consumption, one-family house
Abstract
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The article presents the history (since 1946 to present) of legal provisions related to the thermal protection of buildings. On example of a selected one-family house was made calculations of heat load and seasonal heat demand during the periods still changing demands related to thermal insulation of building dividing wall and energy consumption. Then the heating costs for analysed object in individual period were estimated. The analysis included heating costs for the heat which is received from combustion coal, natural gas, heating network and fuel oil. The article ends with a summary and conclusions draw from the calculation results and analysis performed of these results.