I began the three
years Ph.D. program in Structural Engineering in November 2010. During the first year of the Ph.D. program I
focused on the behavior of buildings subjected to severe structural damages
like the loss of one or more columns at the ground floor due to accidental or
man-made explosions (for an example of such events, see the collapse of the
Ronan Point tower - 16 May 1968). A
procedure to evaluate the capacity of a structural system (e.g. building) to withstand
structural damages (structural robustness) is proposed in a first publication
together with a study on the simulation of gas explosions (for an example of
such events, see the case of Buncefield, London - 11 December 2005):
"Olmati P, Petrini F, Bontempi F. Numerical analyses for the structural
assessment of steel buildings under explosions. Structural Engineering and
Mechanics 2013; 45(6): 803-819". A
second publication regards the structural robustness of steel truss bridges
(see the collapse of the I-35W Minneapolis Bridge): "Olmati P, Gkoumas K,
Brando F, Cao L. Consequence-based robustness assessment of a steel truss
bridge. Steel and Composite Structures 2013; 14(4): 379-395".
During the second year
I spent five months (from February 2012 to July 2012) at the Lehigh University
(Bethlehem, PA, USA) under the supervision of Prof. Clay Naito, performing
research on the performance assessment of insulated panels subjected to
close-in detonations. Detailed numerical
simulations (using the LS-Dyna software) were carried out in order to assess
the advantages in terms of scabbing and breach resistance of the insulated
panels versus the classic concrete panels.
Experimental tests were conducted at the Air Force Research Laboratory
in Panama City, FL, USA. The report of
the experimental test is being approved for the "Statement A - for public
realize and unlimited distribution" following the rules of the United
State Department of Defense for being published.
In the autumn of 2012
I participated at the "Blast Blind Simulation Contest 2012 - assessment of
the deflection of reinforced concrete slabs subjected to a blast demand
(http://sce.umkc.edu/blast-prediction-contest)". The contest was sponsored in collaboration
with American Concrete Institute (ACI) Committees 447 (Finite Element of
Reinforced Concrete Structures) and 370 (Blast and Impact Load Effects), and
UMKC School of Computing and Engineering.
The team was composed by Mr. Olmati (myself), Mr. Trasborg (Lehigh
University), Dr. Sgambi (Politecnico di Milano), Prof. Naito (Lehigh
University), and Prof. Bontempi (Sapienza University of Rome). The performed simulation was declared the
Winner of the concurring category and the team is invited to publish a paper in
a special publication of the American Concrete Institute (ACI) journal.
During the third year
I focused on the probabilistic aspects of the design for blast resistant
structures. In particular, I implemented
in blast engineering the probabilistic theory developed in earthquake engineering. The fragility analysis was carried out for
precast concrete cladding wall panels subjected to a terroristic vehicle bomb
attack, and the proposed approach was verified and validated by reliability
analyses performed by Monte Carlo simulations.
A paper on this study has been accepted for publication: "Olmati P,
Trasborg P, Naito CJ, Bontempi F. Blast resistance of reinforced precast
concrete walls under uncertainty. International Journal of Critical
Infrastructures, 2013". Moreover a
second paper has been submitted to the Structural Safety journal: "Olmati
P, Petrini F. Development of fragility curves for cladding panels subjected to
blast load".
The study on the
performance-based blast engineering continued at the National Technical
University of Athens where I spent about three months (from mid-May to
September 2013) under the supervision of Prof. Charis J. Gantes and Prof.
Dimitrios Vamvatsikos. The fragility
analysis was carried out for a steel built-up blast resistant door subjected to
an accidental explosion of ammunitions, and in a similar manner to the previous
studies, the proposed approach was verified and validated by reliability
analyses performed by Monte Carlo simulations.
Moreover, a safety factor was provided in order to design the steel
built-up door with the common state of the practice method. The preparation of a journal paper on this
topic in ongoing: "Olmati P,
Petrini F, Vamvatsikos D, Gantes CJ. Safety factor and fragility analysis for
structures subjected to explosions: the case of steel built-up blast resistant
doors".
In July 2013 I was
involved in an experimental test on concrete cladding wall panels subjected to
detonation of explosive. The test was
executed at the testing site of the R.W.M. ITALIA s.p.a. (www.rwm-italia.com). Moreover, detailed numerical simulations were
carried out in order to reproduce the experimental evidence. The work was presented at the 15th
International Symposium on Interaction of the Effects of Munitions with
Structures (ISIEMS) in Potsdam, Berlin and the journal version of the
conference proceeding is ongoing.
