Oggetto: Ciclo di seminari

SCENARI ESTREMI SULLE STRUTTURE,

25 giugno 2013 ore 14.30 – 17.00,

Aula riunioni Dip. di Ingegneria Strutturale e Geotecnica Facolta' di Ingegneria Civile e Industriale, Universita' degli Studi di Roma La Sapienza Via Eudossiana 18 - 00184 Roma.

Con piacere si comunicano agli interessati i seguenti seminari su temi relativia situazioni estreme e loro effetti sulle strutture:

14.45 – 15.30: Water-Driven Debris Impact Forces on Structures: Experimental and Theoretical Program, Prof. Clay J. Naito, Lehigh University.

15.30 – 16.15: Development of a Blast and Ballistic Resistant Insulated Wall Panel., Patrick Trasborg, Lehigh University.

16.15 – 17.00:F lexural Models of Reinforced Concrete Beams Under Blast Load, Flavio Stochino, Univesrita' degli Studi di Cagliari,

Cordialmente,Roma, 19 giugno 2013

Prof.Dr.-Ing. Franco Bontempi,

Ordinario di Tecnica delle Costruzioni, Facolta' di Ingegneria Civile e Industriale, Dipartimento di Ingegneria Strutturale e Geotecnica,UNIVERSITA' DEGLI STUDI DI ROMA "LA SAPIENZA", Via Eudossiana 18 - 00184 Roma tel. +39-06-44585.265, cell. +39-339-3956300e-mail: franco.bontempi@uniroma1.it - franco.bontempi@francobontempi.orgweb: www.francobontempi.org - http://w3.disg.uniroma1.it/bontempi/

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Water-Driven Debris Impact Forces on Structures:Experimental and Theoretical Program

Clay J. Naito, Ph.D., P.E.

Associate Professor and Associate ChairDepartment of Civil and Environmental Engineering

Lehigh University13 E Packer Ave

Bethlehem, PA 18015 USAEmail: cjn3@lehigh.edu

P:(610)758-6229 F:(610)758-5553, C:(484)239-8700http://www.lehigh.edu/~cjn3

Abstract

Water-driven debris generated during tsunamis and hurricanes can impose substantialimpact forces on structures that are often not designed for such loads. Thispresentation covers the design and results of an experimental and theoretical programto quantify these potential impact forces. Two types of prototypical debris areconsidered: a wood log and a shipping container.Full-scale impact tests at Lehigh University were carried out with a wooden utilitypole and a shipping container. The tests were carried out in-air, and were designed toprovide baseline, full-scale results. A 1:5 scale shipping container model was usedfor in-water tests in the Oregon State University large wave flume. These tests wereused to quantify the effect of the fluid on the impact forces.Results from both experimental programs are presented and compared withtheoretical predictions. The analytical predictions are found to be in sufficientagreement such that they can be used for design. A fundamental takeaway is that theimpact forces are dominated by the structural impact, with a secondary affectprovided by the fluid.

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Short Bio.:Clay Naito, Ph.D., P.E. is an Associate Professor and Associate Chair of theDepartment of Civil and Environmental Engineering at Lehigh University inBethlehem, PA USA. He is a licensed professional engineer in the states ofCalifornia and Pennsylvania. He is an associate editor of the ASCE Bridge Journaland the Chair of the Precast/Prestressed Concrete Institute Committee on BlastResistance and Structural Integrity. Prof. Naito’s research focuses on Experimentaland Analytical Evaluation of Reinforced and Prestressed Concrete StructuresSubjected to Extreme Events including Earthquakes, Tsunamis, and Intentional BlastDemands.

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Development of a Blast and Ballistic Resistant InsulatedWall Panel

Patrick Trasborg

Department of Civil and Environmental EngineeringLehigh University13 E Packer Ave

Bethlehem, PA 18015 USAP: 610-758-6254

Email: pat310@lehigh.edu

Abstract

Accidental and intentional detonations of high explosives are an unfortunate realityfor not only military facilities, but any building. In the United States, designing forblast loads is required of all military and government structures. Additionally, therehas been a recent emphasis on constructing energy efficient, sustainable buildings.Insulated concrete wall panels can meet both requirements due to the blast resistanceof reinforced concrete and the thermal properties of the interior insulation layer. Thisresearch project focuses on improving the response of an insulated concrete panel toexplosions at both larger and small scaled distance, as well as the ballistic resistanceof the panel. Emphasis is placed on innovative, emulative reinforcement detailing toimprove far scale explosions, while shock resistant materials are utilized within theinsulation layer to improve small scale explosions and ballistic response. Static testsare conducted under both point and uniform loading to obtain resistance functions topredict the dynamic response of the insulated panel. Experimental, numerical, andanalytical results will be discussed.

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Short Bio.:Patrick Trasborg is a Ph.D. student at Lehigh University in Bethlehem,Pennsylvania, United States. He obtained his BS and MS degrees from Lehigh in2010 and 2012. He was a 2009 Moles Scholarship Award winner, a 2010 President’sScholar recipient, and awarded by PCI with a 2011-2012 Daniel P. Jenny Fellowship.Patrick has been involved with numerical modeling for simulating shock waveresponse in ballistic clay. He is currently a research assistant and Dean’s teachingassistant working with Professor Clay Naito.

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Flexural Models of Reinforced Concrete Beams Under Blast Load

Flavio Stochino, Ph.D., P.E.

Department of Civil, Environmental Engineering and ArchitectureVia Marengo 2, University of Cagliari

09123 Cagliari (CA) Italytel: +39 0706755410fax: +39 0706755418

fstochino@unica.it - fstochino@gmail.com http://unica.academia.edu/FlavioStochino

skype: flavio_stochino

Faculty of Architecture of the University of Sassari.Palazzo del Pou Salit, Piazza Duomo 6,

07041 Alghero (SS), Italytel: +39079 9720403

Abstract

Nowadays, the issue of structural safety under blast loading has become a dramaticproblem. The tragic news of the terrorist attacks of recent years raise important,urgent questions regarding the real safety and reliability of our buildings. Extremeloads such as impacts, explosions, etc., can occur in everyday life with unexpectedlyhigh frequency. This seminar deals with the flexural failure of Reinforced Concretebeams under blast loads. The main aim is to develop dynamic and energy modelscapable of evaluating the response of R.C. under explosive load. The seminar iscomposed of three sections. Various dynamic models are developed in Section 1,taking into account the strain-rate sensitivity of both steel and concrete, as well asother nonlinearities in structural behaviour. In Section 2, the same problem is solvedin a different way: starting from the principle of energy conservation. This procedure,less accurate than the previous one, produces very good results regarding midspandisplacement, especially as it requires less computation time. In order to betterunderstand the phenomenon, with the aim of identifying the key parameters instructural response, a sensitivity analysis is developed in Section 3. In this way it is

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possible to attain simple predictive polynomial formulations and, finally, simple tablefor early structural assessment of beams under blast load during the designprocedure.

Short Bio.:Flavio Stochino is a Post. Doc. fellow at University of Sassari. He has defended hisPh.D. thesis “FLEXURAL MODELS OF REINFORCED CONCRETE BEAMSUNDER BLAST LOAD” on March 25th 2013 at University of Cagliari. His researchdeals with extreme loads on structures and construction materials, in particular forwhat concerns energy interactions and relationship between the structuralperformance under seismic and blast loads. He’s interested in blast/impulsive loadingand fire design of R.C. structures, but also in structural optimization problems andmechanics of laminated structures. He has produced several papers for internationaljournals and he has participated and presented academic papers in severalinternational conferences. You can find more information on his profile inAcademia.edu: http://unica.academia.edu/FlavioStochino.