Dan Dubina

Recent research advances on the ECBL approach. Part II: interactive buckling of perforated sections

Abstract Perforated cold-formed steel sections are often used in civil engineering as structural members for residential buildings and storage racks construction. In the case of buildings the perforations are provided to permit piping and bridging, while for rack systems they allow for simple connections between members. The load bearing capacity of these sections are influenced not only by the local buckling, global buckling and interaction between these two, but also by the reduction of cross-sectional properties due to perforations. Because of the wide variety in the size and configuration of perforations, it is impossible to provide a practical design procedure to calculate the ultimate strength of such a type of sections. The main objective of this paper is to calibrate an effective design width formula for the perforated sections and, using the ECBL approach, to evaluate an equivalent α imperfection factor for European buckling curves, in order to adapt them for sections with different perforation patterns.

Design of cold-formed steel structures. : Eurocode 3 : design of steel structures. Part 1-3, Design of cold-formed steel structures

This book is primarily concerned with the design of cold-formed steel members and structures in building construction in Europe. For this reason it is mainly focused on the EN 1993-1-3, and the related parts of EN 1993 (e.g. EN 1993-1-1, EN 1993-1-5, EN 1993-1-8, etc.). Generally, the book contains the theoretical background and design rules for cold-formed members and connections, accompanied by design oriented flow charts and worked examples for common building application. The book was conceived primarily as a technical support for structural engineers in design and consulting offices, but it is expected to be of interest and useful for students and staff members of structural engineering faculties, as well as, for engineers working in steelwork industry. URI http://lib.hpu.edu.vn/handle/123456789/22866 Collections Technology [2729] Steel Bridges Conceptual and Structural Design of Steel and Steel-Concrete Composite Bridges ​ Lebet, Jean-Paul; Hirt, Manfred A. (Taylor and Francis, 2013) This book gives the professional systems engineer the tools to set up a proper and effective analysis of the resources, schedules and parts needed to successfully undertake and complete any large, complex project. This ... Design of Steel Structures: Eurocode 3 Design of Steel Structures. Part 1-1 General Rules and Rules for Buildings ​ ECCS European Convention for Constructional Steelwork (Ernst and Sohn, 2014) This book introduces the design concept of Eurocode 3 for steel structures in building construction, and their practical application. Following a discussion of the basis of design, including the limit state approach, the ... Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges ​ Ellobody, Ehab (Butterworth-Heinemann, 2014) In recent years, bridge engineers and researchers are increasingly turning to the finite element method for the design of Steel and Steel-Concrete Composite Bridges. However, the complexity of the method has made the ... DSpace software copyright

Behaviour of welded connections of moment resisting frames beam-to-column joints

Abstract The importance of welded connections on the behaviour of beam-to-column joints in steel moment resisting frames was the reason to develop an experimental programme focused on the behaviour of welding details. A number of 54 ‘T’ assembly specimens that reproduce the beam-to-column welded joints have been tested. The experimental programme considered the following parameters: steel grade, strain rate, welding type (fillet weld, double bevel butt weld, and single bevel butt weld), and type of loading (monotonic and cyclic pulsating). The behaviour of the different types of welds have been evaluated and compared in terms of both performance and economical aspects.

Cold-formed steel trusses with semi-rigid joints

Abstract An experimental research program aiming to evaluate the semi-rigid behaviour of some typical bolted connections, that are used in cold formed steel plane truss joints, was carried out in the Laboratory of CMMC Department of The ‘Politehnica’ University of Timisoara. From the experimental values of the resistant moment and initial stiffness of the joints, the semi-rigid character of tested joints were established via the Eurocode 3 provisions. A numerical analysis of this type of truss, in which this semi-rigid behaviour is taken into account using the experimental results, is performed in order to demonstrate the improvement of load capacity in comparison with the classical assumptions. Finally, a semianalytical method combined with FEM simulations, calibrated via some experimental results, is proposed, in order to carry out a parametric study on the local behaviour of this type of connection.

Improving the structural robustness of multi-story steel-frame buildings

Although there are numerous hazards that could trigger the progressive collapse of a building, there are limited provisions in related codes regarding the design of structures to withstand exposure to such threats. It is thus expedient to limit the extent of damage to prevent the initiation of progressive collapse. This could be done by usage of the alternate path method, whereby the structure is made to withstand the loss of one or more critical load-bearing elements and prevent disproportionate collapse. In our study, we investigated the resistance of seismically designed steel-frame buildings to progressive collapse, focusing on the contributions of the floor system and beam-to-column connections. The applied element method was used to predict the structural response by nonlinear static and dynamic analyses, with the purpose of determining some robustness criteria, using as reference the ratio of the failure load to the nominal gravity load.

Cyclic Tests on Bolted Steel Double-Sided Beam-To-Column Joints

The key points in the behaviour of Moment Resisting Steel Frames (MRSF) are the beam-to-column joints, located near the dissipative zones. These should posses adequate rotation capacity and resistance in order to resist the earthquake action. Consequently, the recent American design codes [1] include special provisions for classification of MRSF in terms of beam-to-column joint plastic rotation capacity and resistance.

Koiter asymptotic analysis of thin-walled cold-formed steel members

Abstract An imperfection sensitivity analysis of cold-formed steel members in compression is presented. The analysis is based on Koiter’s approach and Monte Carlo simulation. If the modes interaction is correctly accounted, than the limit load and the erosion of critical buckling load can be easily evaluated. Thousands of imperfection can be analysed with very low computational cost and an effective statistical evaluation of limit performance can be carried out. The analysis is done on pallet rack uprights in compression, based on an intensive experimental study carried out at the Politehnica University of Timisoara.

Experimental Evidence of Erosion of Critical Load in Interactive Buckling

AbstractThe paper starts with a selective review of some basic contributions related to local-overall buckling mode interactions in thin-walled steel members. Then, the results of an intensive experimental study carried out at the Politehnica University of Timisoara with the purpose of evaluating the erosion of a theoretical bifurcation load in the distortional-flexural buckling interaction range in pallet rack uprights are presented. Two different sizes of cross sections, with and without perforations, have been studied. To evaluate and quantify the erosion, the erosion of the critical bifurcation load approach is applied. This approach enables one to use the European buckling curves in the Ayrton-Perry format, expressing the imperfection factor (α) in terms of the erosion coefficient (ψ). It allows estimation of the member’s ultimate capacity, taking into account the interaction of sectional (local or distortional) and member (flexural, torsional, or flexural-torsional) instability modes. Test results a...

Beam-to-CFT High-Strength Joints with External Diaphragm. I: Design and Experimental Validation

AbstractThe paper presents the outcomes of an experimental program developed and carried out with the aim of characterizing the behavior of two types of moment-resisting joints in multistory frames...

Beam-to-CFT High-Strength Joints with External Diaphragm. II: Numerical Simulation of Joint Behavior

AbstractThe paper presents the outcome of a finite-element numerical investigation program developed and carried out in connection to a set of experimental investigations performed on welded beam-t...