New Computational Mechanics for Ships and Offshore Engineering ¾
From Construction Stage to Structural Collapse Stage
Cupertino, California, June 18, 2007 \ The 17th (2007) Annual International Offshore and Polar Engineering Conference ¾ ISOPE-2007 Lisbon, the world's largest program of its kind with peer-reviewed papers, will be held at Corinthia Lisboa Hotel, Lisbon (Lisboa), Portugal, July 1-6, 2007.
The 2007 Jin S Chung Award Lecture will be delivered on July 3 in the Hotel by Yukio Ueda, Professor Emeritus, Osaka University, Japan on: New Computational Mechanics for Ships and Offshore Engineering ¾ From Construction Stage to Structural Collapse Stage.
In keeping with the purpose of this award, the creative and innovative aspects of Professor Uedafs research are highlighted, and some inside stories relevant to the individual research subjects are introduced in the lecture.
In 1962, he received his Ph.D. from Lehigh University, Pennsylvania, U.S.A. The dissertation title is: gElastic, Elastic-plastic and Plastic Buckling of Plates with Residual Stresses.h From then on, his research revolved around those three key words: Elastic-Plastic, Buckling, and Welding Residual Stresses. On the way home from Lehigh University, he visited several universities. He met with Prof. Bruce Johnston at the University of Michigan and Prof. R.W. Clough at University of California at Berkeley. Through these two eventful meetings, he foresaw the bright future of the computational methods of analysis.
Professor Uedafs structural design concept is this: The scantlings of the individual components of a structure should be ideally determined after their functions have been clarified by observing the entire process leading to the overall collapsing state of the structure. In order to execute this concept, he developed several computational methods in the two main fields of mechanics with the aid of the finite element method:
(1) Computational Welding Mechanics for Construction Stage. Professor Uedafs initiated intensive research on welding mechanics late 1960. In 1971, a pioneering paper on "Analysis of Thermal Elastic-Plastic Stress and Strain During Welding by Finite Element Method" was published; this paper laid the basis for detailed analysis on the complex metal behavior during welding, considering the materialsf temperature-dependent physical and mechanical properties.
In parallel to the method for precise transient nonlinear analysis, practical methods for the measurement and the prediction of residual stress were proposed, based on the concept of inherent strain and elastic analysis. The measurement of the three-dimensional distribution of the welding residual stress became possible by his proposed method. Professor Ueda established the framework of computational welding mechanics with some 200 papers.
(2) Computational Structural Mechanics for Ultimate Strength Analysis \ ISUM (Idealized Structural Unit Method). Theoretical methods were developed for the prediction of the ultimate strength of welded steel structures, such as ship and offshore structures, considering both local buckling and plastic collapse. To this end, Professor Ueda proposed and applied the ISUM concept for the investigation of the nonlinear process of ship and offshore structures, leading to collapse or ultimate strength.
Analysis results provided precious information on how to design the strength of structural components. Further, by using these methods, extensive research was conducted to clarify the effects of welding imperfection, such as welding distortion and residual stress, on buckling and the ultimate strength of plates, beam-columns, etc.
These pioneering research works are published in over 450 papers, including those written in Japanese. Their significance is highlighted by the fact that the different disciplines \ structural analysis and welding mechanics \ are integrated into cross-disciplinary and innovative research fields. This forms an essential basis for the idea of design by analysis and production planning based on computational simulation.
These two fields of mechanics are still growing through the efforts of Professor Uedafs young colleagues.
Professor Ueda expresses his pleasure at being selected the recipient of the Chung Award for this year, as well as his appreciation to the colleagues who supported his research for many years.
This presentation will be published in International Journal of Offshore and Polar Engineers, ISOPEfs principal periodical after the conference.
Table of contents of the entire conference and symposium proceedings with 608 peer-reviewed papers are posted on www.isope.org.
By ISOPE Staff, meetings@isope.org ; www.isope.org