In August and September, at the invitation of Shanghai Jiao Tong University "Overseas Master Plan", Yoichi Sumi, former President at Japan Ship Marine Engineering Society and Pro.Sumi at Yokohama National University (YNU), visited School of Naval Architecture, Ocean and Civil Engineering. Pro. Sumi, who has made a lot of achievements in fracture mechanics, strength of ship structure, etc., and has successively undertook the standing committee at the International Ship Marine Structures Conference and other important positions at international academic organizations, gave a series of academic lectures on ship structural mechanics, which had attracted many teachers and students to take part in.

The lecture covered ship fracture accidents that have happened since a century, including the recent accidents, SC Napoli and MOL Comfort and gave the analysis of causes. Besides, Pro. Sumi made the general technical analysis on MOL Comfort accident from the perspectives of fracture mechanics and probability, etc and also proposed some suggestions on  large container ships (8000 teu and above) strength assessment.

Pro. Sumi also systematically expounded the existing fatigue assessment methods and carried on the detailed introduction of basic principle of fracture mechanics and the container ship super thick deck crack extension, capture and control methods, etc., and also deeply and systematically discussed the butt welding of the crack propagation path, stability, and the corresponding crack capture design and control strategy.

Pro. Sumi also introduced the crack propagation research methods which is based on the simulation and is verified by test data, and put forward that it is advantageous to the be captured if the crack propagation expands slowly after going into the residual compression stress area, and to ensure the integrity of the cabin by properly structure of the node designing. Finally, Pro. Sumi introduced the deeply concerned ultrasonic impact (UIT) processing method and its effect on the improvements to the residual stress and the corresponding simulation method, the results of which show that the UIT can effectively improve the fatigue life of welding point.

The lecture series are rich in content, containing the actual engineering background and detailed data, but also further academic discussion and the frontier research achievements. During Pro. Sumi’s visit to SJTU, in addition to academic lecture series, he also guided the PhD students and project  scientific research personnel, and gave lecture courses to graduate students, etc., which will be a great help for OCE faculties to carry out the scientific research and teaching work in the future.

Translated by Tian Na