king - raffaelelandolfo · fig. 2.1 fundamentals of direct displacement -based design ... in order...

Founded in 1224 by the King Frederick II Hohenstaufen , the

University of Naples was the first public University in Italy and now is

one of the biggest of the country.

THE UNIVERITY IN NUMBERS

Facilities:

3 university divisions

13 faculties

26 doctorate schools

79 departments

108 libraries

Courses:

147 degree courses

80 doctorate courses

82 master courses

146 specialization courses

People:

96867 students

1604 professors

1207 researchers

Department of Construction and Mathematical methods in Architecture

Head: Raffaele Landolfo

Department of Structural Engineering

Head: Gaetano Manfredi

Currently, research and academic activities related to steel

structures involve two departments. Innovative facilities are

available for the development of theoretical as well as

experimental activities.

Full Professor in Structural Engineering at University of Naples “Federico II”

Head of the Department of the Constructions and Mathematical Methods inArchitecture

External examiner for MSc in Earthquake Engineering and Structural SteelDesign at Imperial College London

Member of UNI-SC3 Committee on “Steel and Composite Structures”

Expert consultant in several activities of national working group and of theEuropean Project Team dealing with the conversion from ENV to EN of theEurocode 3

Chairman of the ECCS Technical Committee n.13 on Seismic Design since2007

His research activity involves the participation in several national and internationalresearch projects. Engaged in many national and international research projects,he is author of a book and of more than 200 papers.

Steel & Earthquake

Cold-Formed Steel

Sustainable Steel Constructions

Historical Steel Constructions

Composite Materials

Umberto I Gallery, Naples

The University of Naples is active on the research related to steel

structures since the sixties. The main topics currently investigated

at the Department of Constructions and Mathematical Methods

in Architecture are :

Rotation Capacity of Steel Members

High Strength Steel

Displacement Based Design


The principal scope of the work has been the revision of the

classification criteria of steel members actually adopted by

seismic codes and the introduction of a new criterion which

takes into account the principal factors that influence the

structural response.

A wide experimental campaign of monotonic and cyclic tests

has been carried out to investigate the different parameters that

influences the ductility and the overstrength of steel members:

the material strength, different slenderness ratios and cyclic

actions. Indeed, a wide range of cross sections has been tested.

The processing of the experimental results allows to classify the

tested profiles applying different classification criteria proposed

by the technical codes EC3, NTC 08, OPCM 3274.

1. COST Action C26 “Urban Habitat Constructions Under

Catastrophic Events”, European Science Foundation,

WG2 “Earthquake resistance”, years 2006-2010

2. “Capacità rotazionale e criteri di classificazione delle

membrature” RELUIS-DPC, Linea 5, years 2005-2008.

3. “L’influenza della modellazione dei collegamenti sulla

risposta sismo-resistente dei telai di acciaio" PRIN:

“L’influenza dei collegamenti sul comportamento

sismo-resistente delle strutture", years 1999-2001.

The idea that is at the base of the so called Dual-Steel Structures

is to use Mild Carbon Steel (S235, S275, S355) in dissipative

members and High Strength Steel (S460, S690) in non-dissipative

members, that are designed to remain elastic during the

earthquake and so are characterized by high strength demands.

The robustness of the Dual-Steel Structures to severe seismic

action is ensured by their global performance, in terms of

ductility, stiffness and strength.

The main specific objectives of the research are mainly to find

reliable structural typologies and joint/connection detailing for

Dual-steel Building Frames and to develop design criteria and

Performance Based Design methodology for Dual-Steel structures

using HSS.

1. HSS-SERF (High Strength Steel), RFCS 6th Framework

Program on Research, Technological Development

and Demonstration. European Commission, years

2005-2008.

me Fu

F Fn rKi

he Ki Ke

y d

(a) SDOF Simulation (b) Effective Stiffness Ke

1 2 3 4 5 6

Displacement Ductility

0

20

40

60

Dam

pin

g (

%)

0 1 2 3 4 5

Period (seconds)

0

0.1

0.2

0.3

0.4

0.5

Dis

pla

cem

en

t (m

)

5%

10%

15%

20%

30%

d

Te

Elasto-Plastic

Steel Frame

Concrete Frame

Unbonded Prestressing

(c) Equivalent damping vs. ductility (d) Design Displacement Spectra

Fig. 2.1 Fundamentals of Direct Displacement-Based Design

The structural damage due to seismic events is related to strains

developed in members and it is related to their displacements.

Displacements and drifts are the best indicators of structural

damage.

In codified force-based design procedures, displacements are

considered only as an output of the design process. Instead, in

displacement-based design procedures, displacements are the

input data of the design process.

The DBD methodology allows the base shear strength to be

computed case-by-case, in order to meet selected target

displacements.

The main concern is the definition of the displacement shape,

that is usually based on some mixture of theory and empirical

knowledge of similar structures.

When a new structure type is to be analyzed using the DBD

methodology, then the problem to define the displacement

shape come to be solved.

-600

-400

-200

0

200

400

600

800

1000

1200

-0.06 -0.04 -0.02 0 0.02 0.04

Axial deformation (m)

Axia

l fo

rce (

kN

)

Georgescu formulation

0

5

10

15

20

25

0 0.5 1 1.5 2 2.5 3

T (s)

Ps

eu

do

ac

ce

lera

tio

n (

m/s

2) EC8 1s_2s_R1

1s_2s_R2 1s_2s_R3

1s_2s_R4 1s_2s_R5

1s_2s_R6 1s_2s_R7

Average

1. DiSTEEL (Development of a direct displacement-

based methodology for seismic design and

vulnerability assessment), RFCS 7th Framework


and Demonstration. European Commission, years

2006-2009.

Housing

Cube House

Innovative beams


The research is devoted to define a proposal of design

procedure for CFS housing in seismic area, that can be readily

used by designers.

The study has been focused on the seismic behaviour of CFS

shear walls sheathed with oriented strand board and/or gypsum

board panels.

The first part of the experimental phase has been carried out on

two, nominally identical, prototypes. The specimens have been

tested under monotonic and cyclic loading conditions.

In a second phase, a wide experimental campaign aiming at

characterizing the shear behaviour of different sheathings and

sheathing-to-CFS profiles connections has been carried out.

The theoretical and experimental results have been accounted

for the proposal of a seismic design procedure.

1. “Abitazioni per la gestione dell’emergenza” RELUIS-DPC

LINEA10, years 2005-2008.

2. “Metodologie e criteri di progetto per l’housing in cold-

formed in zona sismica“ PRIN: “Strutture metalliche

innovative per la protezione sismica di edifici nuovi ed

esistenti: criteri e metodologie di progetto", years 2003-

2005.

3. “Studio teorico-sperimentale sulla possibilità di impiego

dei profili di acciaio formati a freddo in zona sismica “

PRIN: “Strutture di acciaio innovative per la protezione

sismica degli edifici", years 2001-2003.

Building Construction of Foundation and Primary

Stage School _ BFS Naples _ Lago Patria

The cold-formed steel research group is currently involved in the

realization of the most important structure in cold-formed steel

sheathed with structural panels that is going on in Italy. The

design has been developed for the English Department of the

United Estates and it is under construction right now. The school

extends on 3000m2 , it is organized in 8 buildings, 6 of which are

in cold-formed steel and will open the next year.

The case study is a residential unit of 7,80x7,80m², with two

stories. The total height is of 3 m. This building is a practical

application of the MPN system, that is a steel cold-formed brick.

The design concept was implemented by the arch. Silvio D’Ascia.

The Cube House structure is a tubular panel structure, made of

two vertical and two horizontal walls, composed by MPN. These

elements represent the structural vertical subsystem.

The joints between the vertical walls and horizontal slabs are

made of a half of steel brick.

The main scope of this work is to promote an innovative cold-

formed beam realized thanks to the laser welding technology.

Laser welding, thanks to its characteristics, is an optimal tool for

the automation of welding processes. The main characteristic of

the laser welding is the velocity. The quality of the welding is

high, and high structural performances are guaranteed.

In the first phase a theoretical and experimental study of the

basic connections was performed. To this end, a large

experimental tests campaign was carried out. Connections shear

tests was performed to evaluate the affection of different

geometrical and technical parameters on connections strength

and ductility.

The main scope was the analysis of the structural performances

of the MCL beams, assembled with laser welding. The study

activities was based on the experimental tests performed on real

scale specimens and on FE models with non linear

characteristics implemented on ANSYS software.

Finally the study and the design of a production line of laser

weldings for this beams was carried out.

1. “Progetto e sviluppo di un sistema costruttivo integrato

in acciaio cold-formed basato su tecnologie e

componenti innovative" commissioned by Ben Vautier

S.p.A with funding of Ministero delle Attività Produttive,

years 2006-2008.

2. “Caratterizzazione del processo di saldatura laser di

una trave composta" commissioned by Ben Vautier

S.p.A with funding according to Legge n.598/94, years

2004-2007.

3. “Progetto di sviluppo per una trave modulare

componibile " commissioned by Ben Vautier S.p.A with

funding according to Legge n.46/82, years 2002-2005.

Sustainable Design

LCA of Steel Structures


The research on Sustainable Design deals with the evaluation of

environmental, economical and social performances of steel

structures during the whole life cycle, considering also the

adverse impacts produced on planet, people and economy.

In order to achieve the goal of sustainable structures it is indeed

required to apply integrated design methodology, which take

into account, as a whole, all the sustainability requirements

according to multi-performance life-cycle oriented approach.

According to this, in the last years the topic of durability of steel

structures as well as life cycle structural performance have been

investigating.

Society

Economy

Environment

Sustainable

Development

1. COST Action C25 “Sustainability of Constructions:

Integrated approach to Life-time Structural

Engineering”, European Science Foundation, WG3

“Life-cycle Structural Engineering”, years 2006-2010.

Life Cycle Assessment (LCA) analysis are aimed at evaluating the

environmental burdens associated with a product process or

activity by identifying energy and materials used and wastes

released to the environment.

LCA methodology is characterized by four main stages:

1. Goals and Scope definition

2. Life Cycle Inventory (LCI)

3. Life Cycle Impact Assessment (LCIA)

4. Life Cycle Interpretation

LCA can be used as a useful tool to address the selection

among different design options and identify the critical life cycle

stages, in terms of environmental impacts, associated with

maintenance, repair and rehabilitation of components.

1. COST Action C25 “Sustainability of Constructions:

Integrated approach to Life-time Structural

Engineering”, European Science Foundation, WG3

“Life-cycle Structural Engineering”, years 2006-2010.

2. “Definizione e sviluppo di archivi di dati per la

valutazione del rischio, la pianificazione e la gestione

dell’emergenza” RELUIS-DPC, Linea 10, years 2005-

2008.

Steel Roofing

Steel Bridges


The main scope of the research is to develop a methodology for

the assessment of the vulnerability and the use of reversible

mixed technologies, with regard to historical and monumental

metallic constructions.

The case study was the Dome of the Umberto I Gallery in Naples.

The research program has been articulated through a wide

experimental activity, in order to characterize both the

mechanical properties of historical material and the structural

behavior of riveted connections.

In order to analyze the structural vulnerability and the seismic

capacity of the Dome, three-dimensional finite element models

have been implemented.

In order to guarantee the structural integrity of the constructions,

the research is ongoing in a strengthening solution using FRP.

1. “Vulnerabilità e tecniche di consolidamento reversibili

per le strutture storiche in carpenteria metallica“ PRIN:

“Salvaguardia e riabilitazione strutturale di edifici storici

mediante tecniche miste reversibili ", years 2005-2007.

2. “Metodologie di analisi per la previsione della risposta

strutturale di manufatti architettonici in carpenteria

metallica“ CNR: “Metodi e modelli predittivi del

comportamento strutturale di manufatti in presenza e

in assenza di danno” according to Legge 449/97,

years 2002-2005.

The main scope of the research is to develop a methodology for

the study of the durability and for the assessment of the

vulnerability, with regard to historical and monumental metallic

constructions.

The case study was the historic metal truss railway bridge on

Gesso river, near Foggia. The case studies was selected through

the strong collaboration established between the research unit

and the Italian rail operator Ferrovie dello Stato.

The research program has been articulated through a wide

experimental activity, in order to characterize both the

mechanical properties of historical material and the structural

behavior of riveted connections.

In order to analyze the structural vulnerability and the seismic

capacity of the bridge, three-dimensional finite element models

have been implemented.

1. “Vulnerabilità e tecniche di consolidamento reversibili

per le strutture storiche in carpenteria metallica“ PRIN:

“Salvaguardia e riabilitazione strutturale di edifici storici

mediante tecniche miste reversibili ", years 2005-2007.

2. “Metodologie di analisi per la previsione della risposta

strutturale di manufatti architettonici in carpenteria

metallica“ CNR: “Metodi e modelli predittivi del

comportamento strutturale di manufatti in presenza e

in assenza di danno” according to Legge 449/97,

years 2002-2005.

FRP Reinforcing of Steel Members


The use of FRP for strengthening and repairing metal structures is

not developed as in the case of masonry or reinforced concrete

buildings. With regard to steel historic structures, it is interesting to

perform further experimental tests in order to investigate the

effects of the reinforcement on the ductility of the members, on

the possibility to prevent with the FRPs global and local buckling

phenomena in compression elements and to assess their

suitability in the consolidation of connections.

In order to investigate the behaviour of compression iron

elements strengthened with FRP a test campaign has been

undertaken in cooperation with the University of Liege (ULg). The

experimental program included tests on stocky elements with

and without FRP, both in tension and in compression. Also, tests

on slender columns have been performed with and without FRP

so as to investigate the influence of the latter on the buckling

resistance.

1. PROHITECH (Earthquake Protection of Historical Building

by Reversible Mixed Technologies), in 6th Framework


and Demonstration. European Commission. Contract

number: INCO-CT-2004-509119, WG8 “Numerical

Analysis”, years 2005-2008.

MSc Thesis

PhD Thesis

Second Level Master Courses

In the last years, the University of Naples promoted many courses and products in the

field of steel structures.

Raffaele Landolfo was the tutor of more than 50 MSc thesis and PhD thesis.

Raffaele Landolfo was the tutor of more than 30 BSc + MSc thesis, at the faculties of Structural Engineering and Architecture.Some of them were awarded by ACAI (Association of Italian Steelwork Producers), and published on a famous Italian technical review (Costruzioni Metalliche):

Laura Grazia MarinielloInnovation and Construction: Design of a cfs system for buildings in seismic zoneACAI AWARD YEAR 2005-2006

Susanna TrotorelliInnovative earthquake resisting Techniques for the design of steel Structures ACAI AWARD YEAR 2006-2007

Consiglia MozzilloDesign of a steel pedestrian bridge with a bi-helicoidalstructureACAI AWARD YEAR 2007-2008

Gaetano Della Corte - 2001 Seismic stability of elasto-plastic frames

Gianmaria Di Lorenzo - 2002Theoretical-experimental study of an innovative cold-formed steel beam

Luigi Fiorino - 2003Seismic behaviour of sheated cold-formed steel stud shear walls: an experimental investigation

Mario D’Aniello - 2007Steel dissipative bracing systems for seismic retrofitting of existing structures: theory and testing

Maria Rita Guerrieri - 2007The laser welding as an innovative technology for cold-formed steel structural systems

Lucrezia Cascini - 2008Atmospheric corrosion and durability design of metal structures

Manuela Brescia - 2008Rotation capacity and overstrength of steel members for seismic design

Ornella Iuorio - 2008Design procedures for cold-formed steel housing in seismic area

General principles of design and structural types

in steel structures

Stability of steel structures

Design and detailing of connections

Steel and Architecture

Tension Structures and Glass Engineering

Cold-Formed thin-walled members and structures

Steel structures in tall buildings and large

coverings

Design, Fabrication and Erection of Steel Bridges

Composite Structures

Aluminium Structures

Steel in Refurbishment

Masts, Towers, Tanks and Silos

Provisional Structures and Fire Design

Academic e-learning

Training Activities for Designers

National and International Publications

The dissemination of the steel Research Activities is traditionally made trough scientific

publications. But many other activities are devoted to promote the use of steelwork in

Italy, trough divulgative publications, training courses for designers and e-learning for

academic teaching.

The e-learning project “Federica@” is one of the

first web learning projects promoted by the Italian

universities.

The steel topics are present in this context by

means of many structural engineering lessons.

To promote the use of steelwork in Italy the Steel

Research Activities are also advertised in training

courses for Practitioners and Designers.


Research Activities are published on different

media:

Proceedings of International Conferences

Proceedings of National Conferences

National and International Journals

To promote the use of steelwork in Italy the Steel Research Activities are published on different media:

Design Guides for Engineers:

1. De Marco T., Landolfo R., Salvatore W. Acciai strutturali, prodotti e sistemi di unione (Ed. Promozione Acciaio, Milano, 2007).

2. De Marco T., Landolfo R., Salvatore W. Edifici monopiano in acciaio ad uso industriale (Ed. Promozione Acciaio, Milano, 2007).

3. Ghersi A., Landolfo R., Mazzolani F. M. Design of metallic cold-formed thin-walled members (Spon Press, London, 2001).

4. Mazzolani F. M., Landolfo R., Dubina D., Da Silva S. Design of steel structures for buildings in seismic areas (next)


Research Activities are published on different

media:

National Divulgative Reviews

In 2007 Raffaele Landolfo was appointed as Chairman of TC 13, the Technical Committee n.13 “Seismic Design” of the European Convention for Constructional Steelwork (ECCS).

TC 13 Activities:

Creation of Technical Working Groups to identify weakness in the European Codification

Production of Technical Documents addressing these issues with the aim to contribute to the new generation of codes

Collection of design example from different countries

Creation of the TC13 network of knowledge and background of members by means of the ECCS web-site

Extension of the network outside Europe promoting and organizing workshop in cooperation with USA and Japan

Corrections to EC8 in its present format

Proposals for a next generation EC8

Publications of EUROPEAN RECOMMENDATION and DESIGN MANUALS