Search Results

11 - 20 of 107 items :

  • "Structural steels" x
Clear All

volume fraction fF on results of ductile fracture simulation for S235JR steel under multi-axial stress states”, Key Engineering Materials - Fracture and Fatigue of Materials and Structures 598: 113-118, 2014. 24. P. G. Kossakowski, “An analysis of the Tvergaard parameters at low initial stress triaxiality for S235JR steel”, Polish Maritime Research: 21, 100-107, 2014 25. PN-EN 10025-2:2007 Hot-rolled structural steel. Part 2 - Technical delivery conditions for non-alloy structural steels. 26. PN-EN 10002-1:2004 Metallic materials - Tensile testing - Part 1: Method of

; 49 (14):1152–4. [7] Harničárová M., Zajac J., Stoic A. Comparison of different material cutting technologies in terms of their impact on the cutting quality of structural steel. Technical Gazette 2010; 17 (3): 371-76. [8] Steen WM. Laser Material Processing. 2nd editionSpringer–Verlag; 1998. [9] Kaplan A. An analytical model of metal cutting with a laser beam. Journal of Applied Physics 1996; 79 (5): 2198–2208. [10] Kar A., Rockstroh T., Mazumder J. Two-dimensional model for laser-induced materials damage: Effects of assist gas and multiple reflections inside the

, M., Rokosz, K., Lupták, M., Samardžić, I., Kozak, D., Hloch, S. (2013). Influence of longitudinal cold rolling on the surface topography of low carbon structural steel. Technical Gazette, 20 (4), 705-709. [5] Valíček, J., Müllerová, J., Szarková, V., Rokosz, K., Łukianowicz, C., Kozak, D., Koštial, P., Harničárová, M. (2013). A new procedure for the determination of the main technology parameters of rolling mills. In Design and Analysis of Materials and Engineering Structures. Springer, 15-25. [6] Valíček, J., Držík, M., Hryniewicz, T., Harničárová, M., Rokosz, K

Abstract

The problem of transition zone of structural steel element connected to concrete is discussed in the following paper. This zone may be located for instance in specific bridge composite girder. In such case the composite beam passes smoothly into concrete beam. Because of several dowels usage in the transition zone, the problem of uneven force distribution were discussed through analogy to bolted and welded connections. The authors present innovative solution of transition zone and discuss the results, with emphasis put on the transition zone structural response in term of bending capacity, failure model and force distribution on the connection length. The article wider the already executed experimental test and presents its newest results.

Abstract

This paper focuses on the analysis of two towers of an industrial plant exhibiting extreme deflection during service loads under heavy wind conditions. The towers are 90 m and 35 m in height, respectively and are interconnected with structural steel operating platforms.

The nuts have flown off at some bolted joints in the interconnecting steel structure due to high stress induced by deflections.

The deflections measured at the structural steel towers had nearly twice the value permitted by the respective standard in the case of the 90 m high tower and approached the value permitted by the standard in the case of the 35 m high tower.

The herein detailed complex study - covering the strength analysis of the towers, the analysis of wind effects, and the review of the foundations - has been elaborated in order to determine the causes and consequences of the experienced deflections at the plant as well as to conclude the eventual actions to be taken.

The primary consideration for the conduction of the tests and analyses the determination of the eventual actions to be taken was to retain the towers and not to have them demolished.

Plasma Nitriding as a Prevention Method Against Hydrogen Degradation of Steel

Aim of this paper is evaluation of susceptibility of plasma nitrided structural steel to hydrogen absorption and degradation. Structural steel, nitrided at glow discharge in the gas mixture of various N2, H2, Ar content was subjected to cathodic hydrogen charging in acid solution simulating the aged engine oil. The effect of the nitrided layers on the hydrogen transport and on the irreversible trapping was evaluated by the measurements of the hydrogen permeation rate and by the vacuum extraction, respectively. Surfaces with modified layers were examined with the use of a scanning electron microscope (SEM) before and after hydrogen permeation tests. In the presence of the not defected compact nitride layer, no hydrogen permeation through the steel has been stated under the experimental conditions. Absorbed hydrogen was accumulated within this layer.

Using the atmosphere of the higher nitrogen to hydrogen ratio at plasma assisted nitriding provides the formation of thin compact nitride zone, highly protective against corrosion and hydrogen degradation.

Abstract

The paper is focused on testing the thermal tool holder during milling operation from the point of view shimmy and roughness machined surface of the equipped tool. Experimental work will include testing of surface roughness parameters of the machined surface structural steel 1.0553 (Fe510C1) in combination with the monolith three-lips cutter Kennametal F3AU177BDK38 from cemented carbide coated with TiAIN PVD coating. Experimental machining will distinguish the climb milling and conventional milling and will be done under predetermined conditions, always at 15 cycles and in relation to other types of fixture devices. All testing will be done at a sufficiently rigid machine CNC FGS 40/50. During machining will be measured and subsequently evaluated power machine during the milling process, shimmy and selected parameters of the roughness of the machined surface.

Abstract

The main aim of this work is to verify an influence of the response function type in direct symbolic derivation of the probabilistic moments and coefficients of the structural state variables of axisymmetric spherical steel dome structures. The second purpose is to compare four various types of domes (ribbed, Schwedler, geodesic as well as diamatic) in the context of time-independent reliability assessment in the presence of an uncertainty in the structural steel Young modulus. We have considered various analytical response functions to approximate fundamental eigenfrequencies, critical load multiplier, global extreme vertical and horizontal displacements as well as local deformations. Particular values of the reliability indices calculated here can be of further assistance in the reliability assessment by comparing the minimal one with its counterpart given in the Eurocode depending upon the durability class, reference period and the given limit state type.

Abstract

The main purpose of this work is to verify the influence of the weighting procedure in the Least Squares Method on the probabilistic moments resulting from the stability analysis of steel skeletal structures. We discuss this issue also in the context of the geometrical nonlinearity appearing in the Stochastic Finite Element Method equations for the stability analysis and preservation of the Gaussian probability density function employed to model the Young modulus of a structural steel in this problem. The weighting procedure itself (with both triangular and Dirac-type) shows rather marginal influence on all probabilistic coefficients under consideration. This hybrid stochastic computational technique consisting of the FEM and computer algebra systems (ROBOT and MAPLE packages) may be used for analogous nonlinear analyses in structural reliability assessment.

Abstract

The main aim of this paper is to present a Stochastic Finite Element Method analysis with reference to principal design parameters of bridges for pedestrians: eigenfrequency and deflection of bridge span. They are considered with respect to random thickness of plates in boxed-section bridge platform, Young modulus of structural steel and static load resulting from crowd of pedestrians. The influence of the quality of the numerical model in the context of traditional FEM is shown also on the example of a simple steel shield. Steel structures with random parameters are discretized in exactly the same way as for the needs of traditional Finite Element Method. Its probabilistic version is provided thanks to the Response Function Method, where several numerical tests with random parameter values varying around its mean value enable the determination of the structural response and, thanks to the Least Squares Method, its final probabilistic moments.