Podwal 3/31/20

Bruce Podwal Seminar Series


Hydroelasticity of Floating Structures:

Overview, Applications, and Research Needs


H. Ronald Riggs, PhD, PE

Professor Emeritus, University of Hawaii 

12 – 1 pm, Tuesday, March 31, 2020

Exhibit Room, GSOE first floor, Steinman Hall

Light Lunch will be served

Abstract:  Offshore structures’ response to wave loads are critically important in their design. For slender tubular structures, it is often assumed that the wave field is not affected by the structure. However, for larger structures, the wave field is affected in two ways. First, the presence of the structure causes the incoming wave to be diffracted, and this causes a force on the structure. If the structure is moving, then the motion itself causes new “radiated” waves. Many floating offshore structures are relatively stiff and only rigid body motion causes substantial radiated waves. This is a typical hydrodynamics problem. However, if there is substantial deformational motion, such as for very large or very flexible structures, then the deformational motion is important when solving the hydrodynamics. This fluid-structure coupled problem is referred to as hydroelasticity.

     In this talk I will present a broad overview of hydroelasticity, applications for it, and indicate where research and development needs still exist. Given the diverse audience, a primary goal is to lay out the opportunities in this area of research and practice as well as the technical backgrounds and skillset that are desirable to be active in hydroelasticity. However, I will avoid too many technical details.

       Examples of exciting new applications that are under consideration around the world include floating bridges, submerged bridges, and floating offshore wind platforms.

Biography:  Prof. Riggs retired in 2019 from the Department of Civil & Environmental Engineering at the University of Hawaii after 32 years. He currently operates NumSoft Technologies, whose primary product is the hydroelastic computer code HYDRAN-XR (www.hydran-xr.com). Prof. Riggs received his Ph.D. in structural engineering from UC, Berkeley. A major part of his work has been hydroelasticity of floating structures, co-organizing in 1991 the 1st International Workshop on Very Large Floating Structures. He was also involved in the U.S. Navy’s Mobile Offshore Base program. Prof. Riggs is editor emeritus of the J of Waterway, Port, Coastal and Ocean Engineering, past chairman of the ASME Division of Ocean, Offshore, and Arctic Engineering and co-organizer of the 2009 28th International Offshore Mechanics and Arctic Engineering Conference. He is a Fellow of ASCE and ASME, and he is a licensed professional engineer.