Flexual buckling of structural glass columns. Initial geometrical imperfection as a base for Monte Carlo simulation

In this paper Monte Carlo simulations of structural glass columns are presented. The simulation was performed according to the analytical second order theory of compressed elastic rods. A previous research on shape and size of initial geometrical imperfections is briefly summarized. An experimental analysis of glass columns that were performed for evaluation of equivalent geometrical imperfections is mentioned too

Laminated structural glass plates. Numerical and experimental analysis

Tento příspěvek pojednává o experimentální a numerické analýze desek z vrstveného konstrukčního skla. V rámci výzkumu byla experimentálně otestována tři zkušební tělesa obdélníkového tvaru rozměrů 1000 mm / 1500 mm s využitím metody vakuování. Numerické simulace byly provedeny na pěti rozdílných numerických modelech vytvořených v různých programech založených na metodě konečných prvkůThis paper deals with an experimental and numerical analysis of laminated glass plates transversally loaded. In the frame of research three specimens were experimentally tested using vacuum test method. Glass specimens were rectangular shape with dimensions 1000 mm / 1500 mm. Numerical simulations were carried out by five different numerical models which were developed using software based on finite element metho

Numerical analysis of behaviour of compression members made of laminated structural glass

Příspěvek pojednává o návrhu tlačených prutů z monolitického i vrstveného konstrukčního skla. Skleněné tlačené pruty jsou analyzovány pomocí numerických modelů provedených v programech RFEM a ANSYS s uvažováním proměnné hodnoty modulu pružnosti ve smyku mezivrstvy. Získané hodnoty kritických sil, napětí a deformací jsou potom porovnávány s hodnotami z analytického výpočtu.This paper deals with design of compression members made of monolithic and laminated structural glass. Glass columns are analyzed by numerical models made in RFEM and ANSYS software with consideration of variable value of the interlayer shear modulus. The obtained elastic critical forces, stresses and deflections are compared with the values from the analytical calculation according to the second order theory

Geometrically nonlinear numerical analysis of beams of monosymmetric thin-walled cross-sections loaded perpendicularly to the plane of symmetry

Příspěvek se zabývá geometricky nelineární analýzou ocelových nosníků jednoose symetrického tenkostěnného průřezu zatížených kolmo k rovině symetrie excentricky ke středu smyku. Numerická analýza vybraných příčně zatížených nosníků je provedena v programu Dlubal RFEM metodou konečných prvků. Na základě výsledků je studována vhodnost použití interakčního vztahu pro posouzení ohybu s klopením a kroucení.The paper deals with geometrically nonlinear analysis of steel beams of monosymmetric thinwalled cross-sections loaded perpendicularly to the plane of symmetry eccentrically to the crosssection shear centre. Numerical analysis of selected transversely loaded beams is performed using Dlubal RFEM code based on finite element method. Accuracy of interaction formula for bending with lateral torsional buckling and torsion is studied

Stability of thin-walled beams with lateral continuous restraint

Kovové tenkostěnné nosníky jsou běžně používány jako součásti nosných konstrukcí. Jejich odolnost je zpravidla limitována vyčerpáním vzpěrné únosnosti v důsledku stabilitních problémů. Může být zvýšena v případě, kdy je tenkostěnný průřez příčně podepřen např. pomocí prvků opláštění nebo stropní konstrukce. Příspěvek se zabývá možnostmi výpočtu kritického zatížení potřebného pro stanovení vzpěrné únosnosti ohýbaných tenkostěnných nosníků s příčným spojitým podepřením.Metal beams of thin-walled cross-sections have been widely used in building industry as members of load-bearing structures. Their resistance is usually limited by lateral torsional buckling. It can be increased in case a beam is laterally supported by members of cladding or ceiling construction. The paper deals with possibilities of determination of critical load of thin-walled beams with lateral continuous restraint which is crucial for beam buckling resistance assessment

Material and geometrical characteristics of structural steels based on statistical analysis of metallurgical products

The experimental research results of material and geometrical characteristics of Czech steel are given in the presented paper. Measurements are carried out for the yield strength of plates made of steel grade S355. The values measured are used to compute axial resistances which are compared with the resistance resulting from standard (nominal) values. In this paper, there was used a statistical information for evaluating the results of strength measurements on a series of plates and hot‐rolled profiles under tension to determine the adequate partial γM0 safety factor. Santrauka Straipsnyje pateikti Čekijos plienų mechaninių ir geometrinių charakteristikų eksperimentinių tyrimų rezultatai. Atlikti S355 klasės plieno plokštės takumo stiprio matavimai. Nustatytos reikšmės naudojamos ašiniam stipriui apskaičiuoti, o gauti rezultatai palyginti su standartinėmis (nominaliosiomis) vertėmis. Plieno plokščių ir karštai valcuotų profilių tempiamojo stiprio matavimo rezultatams įvertinti pasitelkta statistinė informacija. Įvertintas dalinio patikimumo koeficiento γM0 adekvatumas. First Published Online: 14 Oct 2010 Reikšminiai žodžiai: medžiaga, plienas, takumo stipris, patikimumas, konstrukcija, projektavimas, atsitiktinis dydis

Stability problems of steel‐concrete members composed of high‐strength materials

The presented paper deals with the stochastic analysis of the ultimate limit states of steel‐concrete building members. The load carrying capacity of steel‐concrete columns, comprising of steel profiles encased in high strength concrete, in compression is analyzed. The first part of the paper lists assumptions for the determination of the theoretical load carrying capacity of the column. Principles of elasticity and plasticity are used to determine stresses in the concrete and steel sections. Statistical characteristics of input material and geometrical imperfections are listed. Results of the theoretical analysis are then compared with results of experimental research. Statistical characteristics of obtained results of the theoretical analysis were verified using statistical characteristics obtained from experimental research. Numerical simulation LHS and Monte Carlo methods, which take into account the influences of variability of input imperfections, were employed. The influence of the utilization of the plastic reserve in the determination of the load carrying capacity of the analysed strut is shown. The influence of the initial geometric imperfections of initial strut curvature on the load carrying capacity is also presented. Santrauka Straipsnyje pateikta plienbetonio pastatu elementu didžiausiu ribiniu būkliu stochastine analize, analizuojama plienbetonio kolonu, sudarytu iš plieniniu profiliuočiu, padengtu didelio stiprio betonu, laikomoji galia gniuždant. Pirmoje straipsnio dalyje išvardytos kolonos teorines laikomosios galios nustatymo prielaidos. Tamprumo ir plastiškumo principai taikyti itempiams betono ir plieno skerspjūviuose nustatyti. Nustatytos medžiagu ir geometriniu defektu statistines charakteristikos, teorines analizes rezultatai palyginti su eksperimentiniu tyrimu rezultatais. Teorines analizes metu gautu rezultatu statistines charakteristikos patikrintos taikant iš eksperimentiniu tyrimu gautus statistinius rodiklius. Pritaikytas skaitinis modeliavimas LHS ir Monte Karlo metodais, kurie ivertina pradiniu defektu kintamumo itaka. Parodyta plastiškumo atsargos naudojimo itaka, nustatant analizuojamojo statramsčio laikomaja galia, pateikta pradinio statramsčio išlinkio pirminiu geometriniu defektu itaka laikomajai galiai. First Published Online: 10 Feb 2011 Reikšminiai žodžiai: medžiagos, plienas, betonas, struktūra, defektai, susilpnejimas, patikimuma

Fatigue Resistance and Durability of New Mechanical Connections of Currently Developed Temporary Steel Footbridges and Railway Bridges

On the workplace of paper authors, the experimental studies of the fatigue behaviour and fatigue resistance of several new types of steel mechanical connections have been performed recently. The problems of mechanical connections mentioned above have been solved in the past within the projects of the development of new types of advanced temporary steel bridges and footbridges, with the support of the programme of applied research, development and innovations of the Technology Agency of the Czech Republic. These newly developed connections represent the assembly joints based on the bolts and pins together with plates. Within this investigation, fatigue tests of connections have been performed. The experimental studies have been oriented to the verification of the behaviour of those connections and especially, the fatigue strength, and subsequently the fatigue resistance and durability of the structural detail according to the configuration and structural design.On the workplace of paper authors, the experimental studies of the fatigue behaviour and fatigue resistance of several new types of steel mechanical connections have been performed recently. The problems of mechanical connections mentioned above have been solved in the past within the projects of the development of new types of advanced temporary steel bridges and footbridges, with the support of the programme of applied research, development and innovations of the Technology Agency of the Czech Republic. These newly developed connections represent the assembly joints based on the bolts and pins together with plates. Within this investigation, fatigue tests of connections have been performed. The experimental studies have been oriented to the verification of the behaviour of those connections and especially, the fatigue strength, and subsequently the fatigue resistance and durability of the structural detail according to the configuration and structural design

Lateral-torsional buckling of laminated structural glass beams. Experimental study

This paper deals with experimental research of stability behaviour of laminated structural glass beams. The purpose of the research is the evaluation of lateral-torsional buckling resistance and actual behaviour of the beams due to absence of standards for design of glass load-bearing structures. The experimental research follows the previous one focusing on measuring of initial geometrical imperfections of glass members and experimental evaluation of flexural buckling resistance of structural glass columns. Within the frame of the research 9 specimens were tested. All of them were of the same dimensions - length 2400 mm and width 280 mm but different thicknesses - 12, 16, 20 mm. All the beams were composed of two annealed glass panes bonded together by PVB foil. Beams were loaded by couple of forces symmetrically situated to the mid-span and supports complied with fork boundary conditions. Specimens were loaded by constantly increasing force up to failure. During testing lateral deflection, vertical deflection, angle of torsion and normal stresses at mid-span were measured. Maximum bending moment achieved during testing has been adopted as lateral-torsional buckling resistance. From this values were calculated characteristics and design values according to the EN 1990. Experiment results were compared with lateral torsional buckling resistance calculated according to the buckling curves approach