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Paper Title：Trial Manufacture and Performance Evaluation of Fatigue Crack Growth Restraining Sheets Using a High Water Content Gel – Utilizing Wedge Effects of Corrosion Products –
(Open access DOI 10.2207/qjjws.41.289)

The recipient of the award：Ichihiko Takahashi

About awarded research：
A simple technique of restraining fatigue crack growth utilizing wedge effects of corrosion products was newly proposed and experimentally tested. Crack growth restraining sheets with a high water content gel were manufactured by way of trial and applied to notched plate specimens of steel, and the efficacy of the sheets to restrain crack growth was evaluated by fatigue tests. In order to find a local humid (or wet) corrosive environment, which is most suitable for the crack growth restraint by wedge effects of corrosion products on the crack surfaces, water components absorbed in the gel and effects of a cathode layer as promoting factors of the corrosive reaction were comparatively examined. As a result, it was found that the efficacy of the gel sheets with 3% salt water and synthetic sea water was remarkable (4.1~9.6 times extension in failure life), and the cathode layer (copper-leaf tape) produced certain additional positive effects in those gel sheets.

The certificate of commendation

The commemorative medal