Nonlinear Ship Rolling Motion: The Importance of Physical Modeling, Nonlinear Dynamics and Stochastic Dynamics

Friday, February 15, 2019 - 2:30pm
3110 Etcheverry Hall
Professor Jeffrey Falzarano

Department of Ocean Engineering

Texas A&M University


E-201 Ocean Engineering Seminar Series, Spring 2019


2:00 - 2:30pm Beverages & Refreshments

2:30 - 4:00pm Seminar


This talk will emphasize that the understanding of at least the three titled topics is crucial to accurately predict the occurrence of critical large-amplitude ship-rolling motions possibly leading to capsizing. Only a balanced approach incorporating all three can have the hope of achieving the goals of the International Maritime Organization (IMO)’s proposed Second Generation Ship Stability Criteria. Development of any analytical criteria for dynamic stability assessment involves two steps – first is formulating a model which effectively captures the physics of the problem with reasonable accuracy and the second is the application of analytical techniques to the chosen model.

While developing a model, one needs to adequately understand the relative importance of hydrodynamic and hydrostatic forces and moments; particularly, the roll damping which is at least as important as the hydrostatic restoring moment. Both nonlinearity and coupling of the roll motion to the other degrees of freedom are important. The nonlinearity due to the softening stiffness is particularly important when analyzing roll motion of ships.

The second part of the talk will address the various analytical techniques which can be applied to analyze the probabilistic characteristics (both long term and short term) of roll response caused by the random nature of the wind and wave excitation. Particular focus will be given to the quantification of the probability of escape from the bounded safe region. The calculated escape probability will indicate the reliability of the system. Finally, a physics-based approach such as described herein will be equally applicable to either ship shaped or non-ship shaped floating offshore platforms.


Dr. Jeffrey Falzarano is professor of Ocean Engineering at Texas A&M University. He received his BS degree in Naval Architecture from Webb Institute, his Master’s and Ph.D. from the University of Michigan in Naval Architecture & Marine Engineering. He also received Master’s degrees in Applied Mechanics and Aerospace Engineering from the University of Michigan. At Texas A&M, he is the Director of the Marine Dynamics Laboratory of the newly formed Ocean Engineering Department. He has over 25 years of experience as a faculty member in naval architecture and ocean engineering. He has supervised and graduated over 50 graduate students and has published more than 100 papers in refereed journals and international conference proceedings. He was elected a fellow in both the Society of Naval Architects and Marine Engineers (SNAME) and American Society of Mechanical Engineers (ASME). Prior to his academic career, he worked as a naval architect for the US Coast Guard’s design branch. He has also interned at the US Coast Guard and ABS R&D doing ship stability research. He has also worked as visiting professor at various US Navy research labs and international academic institutions.


Hosted by: Prof. (E) R. W. Yeung, 5104 Etcheverry Hall (, 510-642-8347


Visitor parking: Metered parking (yellow-marked spaces) of multiple no. of hours is available at the Lower Hearst Lot at the 2nd level, with entry to this level located on Scenic Ave. A campus map is available at