An Overview of SNAME’s T&R Activities
SNAME’s Technical & Research Program is designed to serve its members and industry in general. It conducts research on the design, construction, and operation of ships and marine vehicles. Among the products of the T&R Program are publications such as bulletins, guides and reports.
A presentation will be made outlining the objectives of the T&R program, its organization and will describe some of the work currently underway. Also described will be how volunteers are able to participate in T&R work and what general expectations are. Fatigue in Ship Structures
Fatigue cracking in marine structures is a common failure mode, and significant resources are expended in finding cracks and repairing them. These cracks mostly originate at welded connections although there are exceptions. Fatigue assessment requires a knowledge of the fluctuating loading experienced by the ship, and how these translate into cyclic stresses at the detail concerned. There are several methods of fatigue performance prediction depending principally on how detailed the stress information is; some methods depend on so-called nominal stresses while others require detailed knowledge of local stresses. Stress levels depend not only the wave loads and response of the ships but also on the connection types and how well these connections are fabricated. There are uncertainties associated with each of the relevant parameters which combine to make prediction challenging, more so than other types of structural assessment.
As commercial and military ship designs evolve to meet changing demands there are associated changes in structural parameters that often have an influence on fatigue behaviour. For example, larger, faster commercial ships are more dynamically responsive. Such ships are more likely to experience slamming and springing which lead to cyclic stresses distinct from those that arise from wave loading.
This presentation will introduce fatigue as engineering phenomenon and will summarize the parameters most important in characterizing fatigue behaviour. Methods used to predict fatigue performance will be reviewed and will include a discussion of the sources of uncertainty. The focus will be on large commercial vessels built in steel although types of craft will also be included. The presentation will be illustrated with examples of typical fatigue cracks and fractures. The current challenges in fatigue assessment will be discussed as will future trends relevant to fatigue assessment.Speaker Name and Bio
Roger I. Basu, President Roger Basu & Associates Inc.
Roger I. Basu is a structural engineer with more than 45 years of experience. His early experience was in the structural design and analysis of buildings, bridges and offshore structures. For the last 30 years his focus has been on ship and offshore structures. His experience includes work in specialist areas including vibrations, fatigue & fracture and risk and reliability.
Starting in the early 70s Roger worked for a number of engineering companies in the UK and Canada on land-based and marine structures. In 1987 he joined MIL Systems Inc. in Ottawa and worked mainly on naval ship structures. He broadened his experience to include commercial ships structures when in 1997 he took a position with the American Bureau of Shipping (ABS), Houston, Texas. At ABS Roger held a number of positions and retired in early 2012 as the Director of Shared Technology responsible for the development of several technologies applicable to both marine and offshore sectors. For the next two years he was on the faculty of Webb Institute in NY teaching engineering subjects to naval architectural and marine engineering students. Since 2013 he has been the President of his own company, Roger Basu & Associates Inc., based in Toronto, Canada.
Roger holds a Ph.D. in structural engineering from the University of Western Ontario. He is a Professional Engineer registered in the Province of Ontario and is a Fellow of the Society of Naval Architects and Marine Engineers.
17:00 - Deacon Brodies for Meal
18:30 - Networking
19:00 - An Overview of SNAME’s T&R Activities
19:45 - Short Break
20:00 - Fatigue in Ship Structures
21:00 - Networking
21:30 - Meeting end time
Please join us for a no-host pre-dinner and drinks at the Deacon Brodies
on 247 Egin Street.