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Dogariu Adrian

Politehnica University of Timisoara, CMMC, Faculty Member

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Associate Professor at Department of Steel Structures and Structural Mechanics, The Research Centre for Mechanics of Materials and Structural Safety - CEMSIG
Address: Departamentul de Construcții Metalice și Mecanica Construcțiilor - street Ioan Curea 1, Timișoara 300224 România

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Mieczyslaw Kuczma

Poznan University of Technology

Lazaros Melidis

Eng. Mosaad Hassan

Benha University

Mohamed S Mohamed

Tarik Elsalakawy

Benha University

mohammad ali irandegani

Indian institute of Technology,Hyderabad

Dr. Vasilis Sarhosis

Newcastle University

Oregon State University

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Papers by Dogariu Adrian

Numerical Analysis of a Steel Wire Mesh Seismic Retrofitting Techniques for Masonry Structures

The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2015

This article will present the experimental activities and numerical analysis of an intervention t... more This article will present the experimental activities and numerical analysis of an intervention technique efficiency. This technique applies a stainless or zinc coated steel wire mesh (SWM) bonded with epoxy resin to the masonry walls, on one or both sides. Important advantage of this technique may be related to its reversibility - wire mesh fixed with epoxy resin can be removed from the masonry wall by heating the resin layer. Steel wire mesh reinforced masonry walls have a complex behaviour and no analytic procedures for design are available; therefore, advanced numerical models confirmed by extended experimental tests are need. The experimental program is presented together with the finite element model adopted for retrofitted masonry specimens. The numerical model is calibrated according to the contact-less and full-field measurements. The experimental tests, carried-out within the framework of a European research project, have included tests on steel wires, on steel meshes, on ...

Dynamic Behavior of Road Structures

The present paper deals with dynamic effect induced by traffic loads in flexible pavements. The d... more The present paper deals with dynamic effect induced by traffic loads in flexible pavements. The dynamic effect is not accounted by current design approaches. This fact is due the high complexity of the dynamic analysis and the difficulty of assessing the real behavioral parameters. In order to obtain confident results, one should use advanced numerical tools such as dedicated finite element software. The numerical software should be able to perform dynamic analysis and to model as accurate as possible the traffic loading conditions. In the framework of this study will be summarized the main design demands and design methods for pavements according with the actual national and European prescriptions. In the same time will be described the possibility to use advanced mathematical procedures based on finite element analysis with the help of ABAQUS code. One pavement flexible system will be comparatively analysis presenting in detail the main steps and introduced parameters such as: def...

Strengthening of Masonry Shear Walls Based on Metal Solutions. Part I: Experimental Investigation

Due to the lack of resistance, to a small deformation capacity and to a low ductility, many mason... more Due to the lack of resistance, to a small deformation capacity and to a low ductility, many masonry buildings in prone seismic areas may need structural interventions. Innovative interventions which will increase the wall capacity and ductility, without a major influence on its stiffness, may be valuable. A number of experiments attempting to establish the retrofitting technique efficiency will be detailed in the article. The proposed technique applies metallic plates as external reinforcing. They are connected by means of chemical anchors or pretension threaded rods, onto one or both sides of the wall. The solution can be applied to internal shear walls and on façades either on piers or spandrel. An important technique advantage may be the reversibility provided by dry steel connections. Limited damage occurs after uninstalling (except for the holes in the walls). Metal sheath reinforced masonry walls have complex behaviour and no analytic rules for design are available. Advanced n...

Behavior of Steel Welded Tapered Beam-column

The Open Civil Engineering Journal, 2017

Steel structural elements with variable cross-section, made of welded plates, are largely used in... more Steel structural elements with variable cross-section, made of welded plates, are largely used in the construction industry for both beams and columns in accordance with the stress and stiffness demand in the structure. These types of elements are mainly used for the design of single storey frames with pitched roof rafters and pinned column base. Rafters and columns can be designed as tapered members made of steel welded plates, respecting the bending moment diagrams for gravitational load combination. This paper deals with experimental tests performed on tapered beam-columns elements, subjected to both bending moment and compressive axial force together with analytical investigation.

Cold Rolling Effects on Material Properties in Pallet Rack Uprights

The Open Civil Engineering Journal, 2017

Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold ro... more Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold rolling process changes the material properties, increasing the yield strength and tensile strength across the section. According to EN1993-1-3, an equivalent yielding strength is allowed to be considered in design to account for the changes in material properties. It has to be mentioned that this approach does not take into account the residual stresses that arise following the forming process. The current paper presents the experimental evidence of residual stresses as result cold rolling process for two pallet rack upright sections. Based on experimental findings, a series of numerical models were created in order investigate the influence of residual stresses onto the load bearing capacity of pallet rack uprights. The experimental program was developed within the CEMSIG Research Centre (http://cemsig.ct.upt.ro) of “Politehnica” University of Timisoara. The increase of yield strength an...

Steel Structure Apartment Extensions for Existing Large Prefabricated Panel Collective Dwellings

Procedia Engineering, 2016

The Romanian existing building stock of collective dwellings is in a vast majority composed of re... more The Romanian existing building stock of collective dwellings is in a vast majority composed of reinforced concrete large prefabricated panel blocks of flats, erected during Communism. According to the 1992 Census, these standardized and widespread buildings housed almost 60 percent of the urban population of the country. Due to the small, inflexible apartments on one hand and the changing living conditions of the contemporary Romanian society on the other, a need for extending the inner surface of the existing flats has been identified. This situation led to the adoption of technically restrictive ground-floor spatial additions and other vernacular solutions that are being applied to upper stories, some of them not being able to provide, in many cases, any forms of long term structural guarantee to their users. The present paper describes a prefabricated steel structure solution for cantilevered apartment extensions that can be independently attached to the façade, as well as some technical connecting details to the existing building. A global structural analysis performed on a virtual model depicting a widespread type of block of flats (Model 770) proves the non-intrusive influence the cantilevered apartment extensions have over the existing buildings, in multiple different scenarios of attachments. Moreover, a FEM analysis of the proposed details further shows the reliability of the examined solution.

Performance based seismic evaluation of a non-seismic masonry building ofmetal sheathed walls - Part II: Study case

Protection of Historical Buildings Proceedings of the International Conference on Protection of Historical Buildings Prohitech 09 Rome Italy 21 24 June 2009 Prohitech 09 Vol 2 2009 Isbn 978 0 415 55805 1 Pags 1015 1020, 2009

&amp;amp;quot;&amp;amp;quot;&amp;amp;quot;1. The Performance Based Evaluation and Ret... more &amp;amp;quot;&amp;amp;quot;&amp;amp;quot;1. The Performance Based Evaluation and Retrofitting Design of masonry buildings is addressed in present paper. General principles, the acceptability criteria associated to different performance level and intervention strategies are reviewed in the first part of the paper. An innovative intervention technique for retrofitting masonry walls using metallic sheathing is proposed and evaluated in terms of strength and ductility performance criteria. In the second part of the paper this technique is applied to retrofitting and historical masonry building. 2. A building designed according only to geometrical consideration (as typical at the beginning of the XX century) has been evaluated and consolidated applying a strengthening solution based on metallic sheathing. On this, purpose a Performance Based Seismic Evaluation procedure was applied using an equivalent FE model. This model, experimentally and numerical calibrated, to simulate the behavior of masonry shear walls strengthened with metal sheathing is applied by ABAQUS code, in order to establish the acceptance criteria, performance levels and building performance.&amp;amp;quot;&amp;amp;quot;&amp;amp;quot;

Influence of imperfections and geometrical discontinuities on the behavior of the steel towers

Research and Applications in Structural Engineering, Mechanics and Computation, 2013

&amp;amp;quot;&amp;amp;quot;This paper analyzes the possible influence of different types... more &amp;amp;quot;&amp;amp;quot;This paper analyzes the possible influence of different types of imperfections on the behavior of the steel towers. Two types of tubular towers, exposed at wind load, will be described. The first one is a wind tower of thin-walled circular section and the second one a high-mast lighting tower of polygonal cross section. In the first case the discontinuities are due to the bolted ring stiffened joints, while in second case are the press-lapped joints. The specific technological imperfections raised from lack of evenness of joints and residual stresses caused by pressing are interacting with the usual cylindrical shell imperfection. Without experimental tests, the study offers the references for the sensitivity of such structures to imperfections and geometrical discontinuities on the buckling behavior.&amp;amp;quot;&amp;amp;quot;

The Behaviour of Beam-Column Elements with Variable I Cross-Sections considering Lateral Restraints

Proceedings of the Eleventh International Conference on Computational Structures Technology

Steel structural elements with variable cross section, made of welded plates, are largely used in... more Steel structural elements with variable cross section, made of welded plates, are largely used in the construction industry for both beams and columns in accordance with the stress and stiffness demand in the structure. These types of elements are mainly used for the design of singles storey frames with pitched roof rafters and pinned column base. Rafters and columns can be designed as tapered members made of steel welded plates, respecting the bending moment diagrams for gravitational load combination. Although they are partially restrained against out of plane buckling by side-rails and roof purlins cooperating with sheeting, in current design practice it is quite difficult to evaluate their influence. This paper deals with nonlinear elastic-plastic analysis and experimental tests performed on tapered beam-columns, parts of portal frames, subjected to both bending moment and compressive axial force. Failure of such members may occur by in-plane bending, local buckling and combination between these two, for members with low non-dimensional slenderness. While for members with intermediate and high non-dimensional slenderness, flexural-torsional buckling, local buckling and combination of these two may occur in function of the web slenderness. Numerical results will be compared with experimental tests, obtained for a relevant number of specimens, in order to check the reliability of the numerically determined ultimate capacity of the elements. The influence of both lateral and torsional restraints applied on the beam-column will also be discussed.

Steel solutions for seismic retrofit and upgrade of existing constructions (Steelretro)

The majority of existing buildings are in need of seismic retrofit. The main reasons are: the ori... more The majority of existing buildings are in need of seismic retrofit. The main reasons are: the original design was not optimised with respect to the required safety level, poor construction quality, modifications or enlargements of buildings during their life and increase in the requirements of the seismic design. Even if steel solutions can often be more efficient and economic, their possibilities are practically unknown and their application has been limited to a few particular cases. The aim of the research proposal focused to set up steel solutions for the seismic retrofit of existing buildings, furnishing design and construction methodologies, tools for dimensioning of elements and connections.

Experimental assessment on shear strengthening of clay brick masonry walls using different techniques

In this paper studies made on strengthening techniques used for shear deficient clay brick masonr... more In this paper studies made on strengthening techniques used for shear deficient clay brick masonry walls are presented. The investigated retrofitting systems were the fibre reinforced polymer (FRP) composites, the reinforced mortar jacketing (RMJ) and the steel wire meshes (SWM). Based on the results obtained, it was proven the effectiveness of the externally bonded techniques for strengthening brick masonry walls. These solutions could be useful in the structural retrofitting of the masonry walls, for improving the shear capacity of the masonry buildings before seismic events or in restoring the shear capacity of the affected walls after an earthquake.

Strength and Ductility of Bolted T-Stub Macro-Components Under Monotonic and Cyclic Loading

labciv.eng.uerj.br

SDSS'Rio 2010 STABILITY AND DUCTILITY OF STEEL STRUCTURES E. Batista, P. Vellasco, L. de Lim... more

Experimental study on laterally restrained steel columns with variable I cross sections

Steel & Composite structures, 2012

ABSTRACT Steel structural elements with web-tapered I cross section, are usually made of welded t... more ABSTRACT Steel structural elements with web-tapered I cross section, are usually made of welded thin plates. Due to the nonrectangular shape of the element, thin web section may be obtained at the maximum cross section height. The buckling strength is directly influenced by lateral restraining, end support and initial imperfections. If no lateral restraints, or when they are not effective enough, the global behaviour of the members is characterized by the lateral torsional mode and interaction with sectional buckling modes may occur. Actual design codes do not provide a practical design approach for this kind of elements. The paper summarizes an experimental study performed by the authors on a relevant number of elements of this type. The purpose of the work was to evaluate the actual behaviour of the web tapered beam-columns when applying different types of lateral restraints and different web thickness.

Soluţii moderne pentru consolidarea şi reabilitarea clădirilor amplasate în zone seismice

Revista AICPS Ediţie …, 2007

... Daniel Grecea1, Sorin Bordea2, Aurel Stratan3, Adrian Dogariu2, Dan Dubină4 ... Deşi metodele... more

Cold Rolling Effects on Material Properties in Pallet Rack Uprights

by Dogariu Adrian and Andrei Crisan

The Open Civil Engineering Journal, 2017

Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold ro... more Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold rolling process changes the material properties, increasing the yield strength and tensile strength across the section. According to EN1993-1-3, an equivalent yielding strength is allowed to be considered in design to account for the changes in material properties. It has to be mentioned that this approach does not take into account the residual stresses that arise following the forming process. The current paper presents the experimental evidence of residual stresses as result cold rolling process for two pallet rack upright sections. Based on experimental findings, a series of numerical models were created in order investigate the influence of residual stresses onto the load bearing capacity of pallet rack uprights. The experimental program was developed within the CEMSIG Research Centre (http://cemsig.ct.upt.ro) of " Politehnica " University of Timisoara. The increase of yield strength and tensile strength across the cross-section was also experimentally determined.

Behavior of Steel Welded Tapered Beam-column

by Dogariu Adrian and Daniel L Nunes

The Open Civil Engineering Journal, 2017

Steel structural elements with variable cross-section, made of welded plates, are largely used in... more Steel structural elements with variable cross-section, made of welded plates, are largely used in the construction industry for both beams and columns in accordance with the stress and stiffness demand in the structure. These types of elements are mainly used for the design of single storey frames with pitched roof rafters and pinned column base. Rafters and columns can be designed as tapered members made of steel welded plates, respecting the bending moment diagrams for gravitational load combination. This paper deals with experimental tests performed on tapered beam-columns elements, subjected to both bending moment and compressive axial force together with analytical investigation.

STRENGTHENING OF MASONRY SHEAR WALLS BASED ON METAL SOLUTIONS. PART II: FE-MODEL FOR THE PERFORMANCE EVALUATION

PROCEEDINGS OF THE ROMANIAN ACADEMY, Series A, 2017

The strength and ductility of a proposed intervention technique for retrofitting masonry walls us... more The strength and ductility of a proposed intervention technique for retrofitting masonry walls using metallic sheathing were experimentally evaluated. Due to the masonry-connector-plate system complexity, a detailed ABAQUS FE-model of masonry shear walls reinforced by metal sheathing, was set up. The numerical model was experimentally calibrated so as to replicate the behaviour of the retrofitted elements allowing parametric analysis. By using the finite element model, a " numerical experiment " was performed in order to set up the behaviour of different retrofitted wall types. An equivalent material able to replicate the numerical behaviour of the retrofitted model was applied in the global analysis. The seismic safety based on the performance approach was evaluated for a study case building. A multi-decisional matrix was proposed for the validation of the retrofitting techniques which combines structural, technical and economic aspects.

Seismic behavior of two steel solutions for apartment extensions in case of large prefabricated reinforced concrete collective dwellings

Behavior of Steel Structures in Seismic Areas STESSA, ISBN 978-112-18127-8

Almost 60% of the urban population of Romania lives in collective dwellings made of large reinfor... more Almost 60% of the urban population of Romania lives in collective dwellings made of large reinforced concrete panels and erected during Communist regime. The standardized projects vastly repeated throughout the country offered equal living conditions to a great number of people. Nowadays, the spatial conformation of the apartments no longer serves the contemporary living condition, mainly because the small spaces and the enclosed and unflexible constructive systems.Vernacular solutions for horizontally extending the individual apartments have been applied, although, these cannot provide, in many cases, any forms of long-term structural guarantee. The present paper describes two opposing solutions of prefabricated steel structures solutions representing cantilevered apartment extensions for an additional interior surface of the apartment. At the same time, a seismic evaluation of the two solution is conducted, establishing the appropriate conditions the two can be applied.

Dynamic Behavior of Road Structures

by Dogariu Adrian and Ciprian Costescu

INTERSECTII/INTERSECTIONS, 2016

The present paper deals with dynamic effect induced by traffic loads in flexible pavements. The d... more The present paper deals with dynamic effect induced by traffic loads in flexible pavements. The dynamic effect is not accounted by current design approaches. This fact is due to the high complexity of the dynamic analysis and the difficulty of assessing the real behavioral parameters. In order to obtain confident results, one should use advanced numerical tools such as dedicated finite element software. The numerical software should be able to perform dynamic analysis and to model as accurate as possible the traffic loading conditions.
In the framework of this study will be summarized the main design demands and design methods for pavements according with the actual national and European prescriptions. In the same time will be described the possibility to use advanced mathematical procedures based on finite element analysis with the help of ABAQUS code. One pavement flexible system will be comparatively analysis presenting in detail the main steps and introduced parameters such as: defining the traffic loading conditions, modeling of the pavement structures, constrains, contact interactions, boundary conditions, material laws etc.

NUMERICAL ANALYSIS OF A STEEL WIRE MESH SEISMIC RETROFITTING TECHNIQUES FOR MASONRY STRUCTURES

The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2015

This article will present the experimental activities and numerical analysis of an intervention t... more This article will present the experimental activities and numerical analysis of an intervention technique efficiency. This technique applies a stainless or zinc coated steel wire mesh (SWM) bonded with epoxy resin to the masonry walls, on one or both sides. Important advantage of this technique may be related to its reversibility-wire mesh fixed with epoxy resin can be removed from the masonry wall by heating the resin layer. Steel wire mesh reinforced masonry walls have a complex behaviour and no analytic procedures for design are available; therefore, advanced numerical models confirmed by extended experimental tests are need. The experimental program is presented together with the finite element model adopted for retrofitted masonry specimens. The numerical model is calibrated according to the contact-less and full-field measurements. The experimental tests, carried-out within the framework of a European research project, have included tests on steel wires, on steel meshes, on 500 by 500 mm retrofitted masonry elements (diagonal tensile tests) and 1500 by 1500 mm masonry walls. The numerical calibration have been made using ABAQUS finite element software. The replacing of simple masonry with an equivalent material with improved behaviour, can be done following the experimental testing results. This kind of approach that considers the retrofitting steel wire mesh as an external reinforcing can really simplify the numerical effort.

Numerical Analysis of a Steel Wire Mesh Seismic Retrofitting Techniques for Masonry Structures

The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2015

This article will present the experimental activities and numerical analysis of an intervention t... more This article will present the experimental activities and numerical analysis of an intervention technique efficiency. This technique applies a stainless or zinc coated steel wire mesh (SWM) bonded with epoxy resin to the masonry walls, on one or both sides. Important advantage of this technique may be related to its reversibility - wire mesh fixed with epoxy resin can be removed from the masonry wall by heating the resin layer. Steel wire mesh reinforced masonry walls have a complex behaviour and no analytic procedures for design are available; therefore, advanced numerical models confirmed by extended experimental tests are need. The experimental program is presented together with the finite element model adopted for retrofitted masonry specimens. The numerical model is calibrated according to the contact-less and full-field measurements. The experimental tests, carried-out within the framework of a European research project, have included tests on steel wires, on steel meshes, on ...

Dynamic Behavior of Road Structures

The present paper deals with dynamic effect induced by traffic loads in flexible pavements. The d... more The present paper deals with dynamic effect induced by traffic loads in flexible pavements. The dynamic effect is not accounted by current design approaches. This fact is due the high complexity of the dynamic analysis and the difficulty of assessing the real behavioral parameters. In order to obtain confident results, one should use advanced numerical tools such as dedicated finite element software. The numerical software should be able to perform dynamic analysis and to model as accurate as possible the traffic loading conditions. In the framework of this study will be summarized the main design demands and design methods for pavements according with the actual national and European prescriptions. In the same time will be described the possibility to use advanced mathematical procedures based on finite element analysis with the help of ABAQUS code. One pavement flexible system will be comparatively analysis presenting in detail the main steps and introduced parameters such as: def...

Strengthening of Masonry Shear Walls Based on Metal Solutions. Part I: Experimental Investigation

Due to the lack of resistance, to a small deformation capacity and to a low ductility, many mason... more Due to the lack of resistance, to a small deformation capacity and to a low ductility, many masonry buildings in prone seismic areas may need structural interventions. Innovative interventions which will increase the wall capacity and ductility, without a major influence on its stiffness, may be valuable. A number of experiments attempting to establish the retrofitting technique efficiency will be detailed in the article. The proposed technique applies metallic plates as external reinforcing. They are connected by means of chemical anchors or pretension threaded rods, onto one or both sides of the wall. The solution can be applied to internal shear walls and on façades either on piers or spandrel. An important technique advantage may be the reversibility provided by dry steel connections. Limited damage occurs after uninstalling (except for the holes in the walls). Metal sheath reinforced masonry walls have complex behaviour and no analytic rules for design are available. Advanced n...

Behavior of Steel Welded Tapered Beam-column

The Open Civil Engineering Journal, 2017

Steel structural elements with variable cross-section, made of welded plates, are largely used in... more Steel structural elements with variable cross-section, made of welded plates, are largely used in the construction industry for both beams and columns in accordance with the stress and stiffness demand in the structure. These types of elements are mainly used for the design of single storey frames with pitched roof rafters and pinned column base. Rafters and columns can be designed as tapered members made of steel welded plates, respecting the bending moment diagrams for gravitational load combination. This paper deals with experimental tests performed on tapered beam-columns elements, subjected to both bending moment and compressive axial force together with analytical investigation.

Cold Rolling Effects on Material Properties in Pallet Rack Uprights

The Open Civil Engineering Journal, 2017

Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold ro... more Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold rolling process changes the material properties, increasing the yield strength and tensile strength across the section. According to EN1993-1-3, an equivalent yielding strength is allowed to be considered in design to account for the changes in material properties. It has to be mentioned that this approach does not take into account the residual stresses that arise following the forming process. The current paper presents the experimental evidence of residual stresses as result cold rolling process for two pallet rack upright sections. Based on experimental findings, a series of numerical models were created in order investigate the influence of residual stresses onto the load bearing capacity of pallet rack uprights. The experimental program was developed within the CEMSIG Research Centre (http://cemsig.ct.upt.ro) of “Politehnica” University of Timisoara. The increase of yield strength an...

Steel Structure Apartment Extensions for Existing Large Prefabricated Panel Collective Dwellings

Procedia Engineering, 2016

The Romanian existing building stock of collective dwellings is in a vast majority composed of re... more The Romanian existing building stock of collective dwellings is in a vast majority composed of reinforced concrete large prefabricated panel blocks of flats, erected during Communism. According to the 1992 Census, these standardized and widespread buildings housed almost 60 percent of the urban population of the country. Due to the small, inflexible apartments on one hand and the changing living conditions of the contemporary Romanian society on the other, a need for extending the inner surface of the existing flats has been identified. This situation led to the adoption of technically restrictive ground-floor spatial additions and other vernacular solutions that are being applied to upper stories, some of them not being able to provide, in many cases, any forms of long term structural guarantee to their users. The present paper describes a prefabricated steel structure solution for cantilevered apartment extensions that can be independently attached to the façade, as well as some technical connecting details to the existing building. A global structural analysis performed on a virtual model depicting a widespread type of block of flats (Model 770) proves the non-intrusive influence the cantilevered apartment extensions have over the existing buildings, in multiple different scenarios of attachments. Moreover, a FEM analysis of the proposed details further shows the reliability of the examined solution.

Performance based seismic evaluation of a non-seismic masonry building ofmetal sheathed walls - Part II: Study case

Protection of Historical Buildings Proceedings of the International Conference on Protection of Historical Buildings Prohitech 09 Rome Italy 21 24 June 2009 Prohitech 09 Vol 2 2009 Isbn 978 0 415 55805 1 Pags 1015 1020, 2009

&amp;amp;quot;&amp;amp;quot;&amp;amp;quot;1. The Performance Based Evaluation and Ret... more &amp;amp;quot;&amp;amp;quot;&amp;amp;quot;1. The Performance Based Evaluation and Retrofitting Design of masonry buildings is addressed in present paper. General principles, the acceptability criteria associated to different performance level and intervention strategies are reviewed in the first part of the paper. An innovative intervention technique for retrofitting masonry walls using metallic sheathing is proposed and evaluated in terms of strength and ductility performance criteria. In the second part of the paper this technique is applied to retrofitting and historical masonry building. 2. A building designed according only to geometrical consideration (as typical at the beginning of the XX century) has been evaluated and consolidated applying a strengthening solution based on metallic sheathing. On this, purpose a Performance Based Seismic Evaluation procedure was applied using an equivalent FE model. This model, experimentally and numerical calibrated, to simulate the behavior of masonry shear walls strengthened with metal sheathing is applied by ABAQUS code, in order to establish the acceptance criteria, performance levels and building performance.&amp;amp;quot;&amp;amp;quot;&amp;amp;quot;

Influence of imperfections and geometrical discontinuities on the behavior of the steel towers

Research and Applications in Structural Engineering, Mechanics and Computation, 2013

&amp;amp;quot;&amp;amp;quot;This paper analyzes the possible influence of different types... more &amp;amp;quot;&amp;amp;quot;This paper analyzes the possible influence of different types of imperfections on the behavior of the steel towers. Two types of tubular towers, exposed at wind load, will be described. The first one is a wind tower of thin-walled circular section and the second one a high-mast lighting tower of polygonal cross section. In the first case the discontinuities are due to the bolted ring stiffened joints, while in second case are the press-lapped joints. The specific technological imperfections raised from lack of evenness of joints and residual stresses caused by pressing are interacting with the usual cylindrical shell imperfection. Without experimental tests, the study offers the references for the sensitivity of such structures to imperfections and geometrical discontinuities on the buckling behavior.&amp;amp;quot;&amp;amp;quot;

The Behaviour of Beam-Column Elements with Variable I Cross-Sections considering Lateral Restraints

Proceedings of the Eleventh International Conference on Computational Structures Technology

Steel structural elements with variable cross section, made of welded plates, are largely used in... more Steel structural elements with variable cross section, made of welded plates, are largely used in the construction industry for both beams and columns in accordance with the stress and stiffness demand in the structure. These types of elements are mainly used for the design of singles storey frames with pitched roof rafters and pinned column base. Rafters and columns can be designed as tapered members made of steel welded plates, respecting the bending moment diagrams for gravitational load combination. Although they are partially restrained against out of plane buckling by side-rails and roof purlins cooperating with sheeting, in current design practice it is quite difficult to evaluate their influence. This paper deals with nonlinear elastic-plastic analysis and experimental tests performed on tapered beam-columns, parts of portal frames, subjected to both bending moment and compressive axial force. Failure of such members may occur by in-plane bending, local buckling and combination between these two, for members with low non-dimensional slenderness. While for members with intermediate and high non-dimensional slenderness, flexural-torsional buckling, local buckling and combination of these two may occur in function of the web slenderness. Numerical results will be compared with experimental tests, obtained for a relevant number of specimens, in order to check the reliability of the numerically determined ultimate capacity of the elements. The influence of both lateral and torsional restraints applied on the beam-column will also be discussed.

Steel solutions for seismic retrofit and upgrade of existing constructions (Steelretro)

The majority of existing buildings are in need of seismic retrofit. The main reasons are: the ori... more The majority of existing buildings are in need of seismic retrofit. The main reasons are: the original design was not optimised with respect to the required safety level, poor construction quality, modifications or enlargements of buildings during their life and increase in the requirements of the seismic design. Even if steel solutions can often be more efficient and economic, their possibilities are practically unknown and their application has been limited to a few particular cases. The aim of the research proposal focused to set up steel solutions for the seismic retrofit of existing buildings, furnishing design and construction methodologies, tools for dimensioning of elements and connections.

Experimental assessment on shear strengthening of clay brick masonry walls using different techniques

In this paper studies made on strengthening techniques used for shear deficient clay brick masonr... more In this paper studies made on strengthening techniques used for shear deficient clay brick masonry walls are presented. The investigated retrofitting systems were the fibre reinforced polymer (FRP) composites, the reinforced mortar jacketing (RMJ) and the steel wire meshes (SWM). Based on the results obtained, it was proven the effectiveness of the externally bonded techniques for strengthening brick masonry walls. These solutions could be useful in the structural retrofitting of the masonry walls, for improving the shear capacity of the masonry buildings before seismic events or in restoring the shear capacity of the affected walls after an earthquake.

Strength and Ductility of Bolted T-Stub Macro-Components Under Monotonic and Cyclic Loading

labciv.eng.uerj.br

SDSS'Rio 2010 STABILITY AND DUCTILITY OF STEEL STRUCTURES E. Batista, P. Vellasco, L. de Lim... more

Experimental study on laterally restrained steel columns with variable I cross sections

Steel & Composite structures, 2012

ABSTRACT Steel structural elements with web-tapered I cross section, are usually made of welded t... more ABSTRACT Steel structural elements with web-tapered I cross section, are usually made of welded thin plates. Due to the nonrectangular shape of the element, thin web section may be obtained at the maximum cross section height. The buckling strength is directly influenced by lateral restraining, end support and initial imperfections. If no lateral restraints, or when they are not effective enough, the global behaviour of the members is characterized by the lateral torsional mode and interaction with sectional buckling modes may occur. Actual design codes do not provide a practical design approach for this kind of elements. The paper summarizes an experimental study performed by the authors on a relevant number of elements of this type. The purpose of the work was to evaluate the actual behaviour of the web tapered beam-columns when applying different types of lateral restraints and different web thickness.

Soluţii moderne pentru consolidarea şi reabilitarea clădirilor amplasate în zone seismice

Revista AICPS Ediţie …, 2007

... Daniel Grecea1, Sorin Bordea2, Aurel Stratan3, Adrian Dogariu2, Dan Dubină4 ... Deşi metodele... more

Cold Rolling Effects on Material Properties in Pallet Rack Uprights

by Dogariu Adrian and Andrei Crisan

The Open Civil Engineering Journal, 2017

Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold ro... more Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold rolling process changes the material properties, increasing the yield strength and tensile strength across the section. According to EN1993-1-3, an equivalent yielding strength is allowed to be considered in design to account for the changes in material properties. It has to be mentioned that this approach does not take into account the residual stresses that arise following the forming process. The current paper presents the experimental evidence of residual stresses as result cold rolling process for two pallet rack upright sections. Based on experimental findings, a series of numerical models were created in order investigate the influence of residual stresses onto the load bearing capacity of pallet rack uprights. The experimental program was developed within the CEMSIG Research Centre (http://cemsig.ct.upt.ro) of " Politehnica " University of Timisoara. The increase of yield strength and tensile strength across the cross-section was also experimentally determined.

Behavior of Steel Welded Tapered Beam-column

by Dogariu Adrian and Daniel L Nunes

The Open Civil Engineering Journal, 2017

Steel structural elements with variable cross-section, made of welded plates, are largely used in... more Steel structural elements with variable cross-section, made of welded plates, are largely used in the construction industry for both beams and columns in accordance with the stress and stiffness demand in the structure. These types of elements are mainly used for the design of single storey frames with pitched roof rafters and pinned column base. Rafters and columns can be designed as tapered members made of steel welded plates, respecting the bending moment diagrams for gravitational load combination. This paper deals with experimental tests performed on tapered beam-columns elements, subjected to both bending moment and compressive axial force together with analytical investigation.

STRENGTHENING OF MASONRY SHEAR WALLS BASED ON METAL SOLUTIONS. PART II: FE-MODEL FOR THE PERFORMANCE EVALUATION

PROCEEDINGS OF THE ROMANIAN ACADEMY, Series A, 2017

The strength and ductility of a proposed intervention technique for retrofitting masonry walls us... more The strength and ductility of a proposed intervention technique for retrofitting masonry walls using metallic sheathing were experimentally evaluated. Due to the masonry-connector-plate system complexity, a detailed ABAQUS FE-model of masonry shear walls reinforced by metal sheathing, was set up. The numerical model was experimentally calibrated so as to replicate the behaviour of the retrofitted elements allowing parametric analysis. By using the finite element model, a " numerical experiment " was performed in order to set up the behaviour of different retrofitted wall types. An equivalent material able to replicate the numerical behaviour of the retrofitted model was applied in the global analysis. The seismic safety based on the performance approach was evaluated for a study case building. A multi-decisional matrix was proposed for the validation of the retrofitting techniques which combines structural, technical and economic aspects.

Seismic behavior of two steel solutions for apartment extensions in case of large prefabricated reinforced concrete collective dwellings

Behavior of Steel Structures in Seismic Areas STESSA, ISBN 978-112-18127-8

Almost 60% of the urban population of Romania lives in collective dwellings made of large reinfor... more Almost 60% of the urban population of Romania lives in collective dwellings made of large reinforced concrete panels and erected during Communist regime. The standardized projects vastly repeated throughout the country offered equal living conditions to a great number of people. Nowadays, the spatial conformation of the apartments no longer serves the contemporary living condition, mainly because the small spaces and the enclosed and unflexible constructive systems.Vernacular solutions for horizontally extending the individual apartments have been applied, although, these cannot provide, in many cases, any forms of long-term structural guarantee. The present paper describes two opposing solutions of prefabricated steel structures solutions representing cantilevered apartment extensions for an additional interior surface of the apartment. At the same time, a seismic evaluation of the two solution is conducted, establishing the appropriate conditions the two can be applied.

Dynamic Behavior of Road Structures

by Dogariu Adrian and Ciprian Costescu

INTERSECTII/INTERSECTIONS, 2016

The present paper deals with dynamic effect induced by traffic loads in flexible pavements. The d... more The present paper deals with dynamic effect induced by traffic loads in flexible pavements. The dynamic effect is not accounted by current design approaches. This fact is due to the high complexity of the dynamic analysis and the difficulty of assessing the real behavioral parameters. In order to obtain confident results, one should use advanced numerical tools such as dedicated finite element software. The numerical software should be able to perform dynamic analysis and to model as accurate as possible the traffic loading conditions.
In the framework of this study will be summarized the main design demands and design methods for pavements according with the actual national and European prescriptions. In the same time will be described the possibility to use advanced mathematical procedures based on finite element analysis with the help of ABAQUS code. One pavement flexible system will be comparatively analysis presenting in detail the main steps and introduced parameters such as: defining the traffic loading conditions, modeling of the pavement structures, constrains, contact interactions, boundary conditions, material laws etc.

NUMERICAL ANALYSIS OF A STEEL WIRE MESH SEISMIC RETROFITTING TECHNIQUES FOR MASONRY STRUCTURES

The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section, 2015

This article will present the experimental activities and numerical analysis of an intervention t... more This article will present the experimental activities and numerical analysis of an intervention technique efficiency. This technique applies a stainless or zinc coated steel wire mesh (SWM) bonded with epoxy resin to the masonry walls, on one or both sides. Important advantage of this technique may be related to its reversibility-wire mesh fixed with epoxy resin can be removed from the masonry wall by heating the resin layer. Steel wire mesh reinforced masonry walls have a complex behaviour and no analytic procedures for design are available; therefore, advanced numerical models confirmed by extended experimental tests are need. The experimental program is presented together with the finite element model adopted for retrofitted masonry specimens. The numerical model is calibrated according to the contact-less and full-field measurements. The experimental tests, carried-out within the framework of a European research project, have included tests on steel wires, on steel meshes, on 500 by 500 mm retrofitted masonry elements (diagonal tensile tests) and 1500 by 1500 mm masonry walls. The numerical calibration have been made using ABAQUS finite element software. The replacing of simple masonry with an equivalent material with improved behaviour, can be done following the experimental testing results. This kind of approach that considers the retrofitting steel wire mesh as an external reinforcing can really simplify the numerical effort.

(RO) TEHNICI DE CONSOLIDARE ANTI-SEISMIC A CLDIRILOR EXISTENTE BAZATE PE UTILIZAREA OELULUI Seminar Internaional organizat în cadrul RFCS STEELEARTH

LUCRĂRILE SEMINARULUI Overview of the STEEL-EARTH project (Steel-based applications in earthquake... more LUCRĂRILE SEMINARULUI
Overview of the STEEL-EARTH project (Steel-based applications in earthquake-prone areas) - acad. Dan Dubina
Performance based evaluation of structures in view of their consolidation - Adrian Dogariu
Strengthening of existing reinforced concrete frames with buckling-restrained braces: general presentation and study case - Aurel Stratan

SEISMIC RETROFITTING OF EXISTING STRUCTURES USING STEEL-BASED SOLUTIONS TEHNICI DE CONSOLIDARE ANTI-SEISMICĂ A CLĂDIRILOR EXISTENTE BAZATE PE UTILIZAREA OŢELULUI International Workshop organised within the framework of RFS2-CT-2014-00022 STEELEARTH

The proceeding includes documents prepared by research team form Politehnica University Timisoara... more The proceeding includes documents prepared by research team form Politehnica University Timisoara, under supervision of acad. Dan Dubină, within the framework of RFCS STEEL-EARTH - Steel-based applications in earthquake-prone areas.
Steel-earth is the first valorisation project in RFCS on earthquake engineering and summarise the efforts in last years aiming at the development of enhanced constructive, design and prenormative solutions. The proposed dissemination activities are of paramount importance to transfer obtained results in current design practice and standards.