Hiroshi Yoshizu

The problems for XML formalization of the formulas for numeric data analysis of the materials field

セマンティックWeb技術を用いて，材料問題解決支援システム構築の問題点抽出を進めている．本報告は，材料の力学問題解決に必要な材料特性データやデータ解析に用いる解析モデル式などの収集を行い，データ解析で数式を取扱う場合のXML記述の問題点について検討した．その結果，数式をXML形式であるMathMLにより記述する場合，材料分野において数式で使用する文字や記号の統一と数式の理解を共通化することで円滑なデータ解析作業が可能である．そこで，統一した文字や記号を提案し，その活用例を示した．

Scatter in Creep-Rupture Data and Long-Time Extrapolation for Ferritic Heat-Resisting Steels.

The scatter in creep-rupture data and the accuracy of prediction by TTP (Time-temperature parameter) method for long-term creep rupture strength have been examined for 16 types of ferritic heatresisting steels. The logarithm of long-term creep rupture time was observed to be normally distributed. The TTP of Larson-Miller (LMP) and Manson-Haferd (MHP) was used for prediction of long-term creep rupture strength. The constants of TTP (C=20 for LMP, Ta=450 and Ya=14.55 for MHP), which are the average values of the optimized constants for each heat, were applied. An excellent prediction of long-term creep rupture strength whose RMS (root mean square) value is less than 0.3 was achieved for 95% of 87 heats of a wide variety of low alloy steels from 0.5Mo steel to 5Cr-0.5Mo steel.