研究者詳細 - 多田　直哉

MISC - 多田　直哉

分割表示 287 件中 121 - 140 件目／全件表示 >>

G031015 比例・非比例ひずみ経路の二軸圧縮試験によるAZ31マグネシウム合金鋳造材の圧縮成形限界に関する検討([G031-01]材料力学部門,一般セッション : 非鉄金属の強度と変形(1))

秋山大輔, 清水一郎, 多田直哉

年次大会 : Mechanical Engineering Congress, Japan 2013 "G031015 - 1"-"G031015-3" 2013年9月

記述言語：日本語出版者・発行元：一般社団法人日本機械学会

Magnesium alloys have special features such as light weight, high specific strength, and good reusability. However, information on the compressive formability of magnesium alloys in multi-axial compressive stress conditions is still limited, nevertheless of their importance in plastic working processes such as forging and extrusion. In the present study, biaxial compression tests of initially isotropic cast AZ31 magnesium alloy were performed along proportional and non-proportional strain paths at room temperature. In the tests, the change of microstructure was observed using a scanning electron microscope. The results revealed that the compressive forming limit of AZ31 magnesium alloy was affected not only by the maximum shear stress but also by the hydrostatic stress. The area fraction of twin, which influences on the compressive flow behavior, was found to vary according to the strain paths.

CiNii Article

CiNii Books

researchmap

207 温度変化と引張り負荷を受けるポリカーボネート基板上金薄膜の有限要素法による変形解析

格日力斯布達, 多田直哉, 清水一郎, 胡亜菲

講演論文集 2013 ( 51 ) "207 - 1"-"207-2" 2013年2月

208 塑性ヒンジ理論を用いた角形鋼管の側面局部圧縮および三点曲げにおける変形吸収エネルギー評価

小原壮人, 小野忠則, 清水一郎, 多田直哉

講演論文集 2013 ( 51 ) "208 - 1"-"208-2" 2013年2月

A Fundamental Study on Plastic Deformation of Metastable Beta-Type Ti-Nb Alloys under Uniaxial and Biaxial Compressions

Ichiro Shimizu, Kazuaki Hisada, Naoya TADA, Yoshito TAKEMOTO

Abstract Book of the International Conference on Experimental Mechanics 2013 & the 12th Asian Conference on Experimental Mechanics 48 - 48 2013年

研究のモチベーション査読

多田直哉

材料 62 ( 7 ) 472 - 472 2013年

924 巨視的ひずみ勾配下の周期境界条件に関する検討(OS9,OS10 合同ポスターセッション,OS・一般セッション講演)

内田真, 多田直哉

計算力学講演会講演論文集 2012 ( 25 ) 378 - 379 2012年10月

OS0302 温間二軸圧縮における初期等方性AZ31マグネシウム合金鋳造材の塑性変形と成形限界

平野聖記, 清水一郎, 秋山大輔, 多田直哉

M&M材料力学カンファレンス 2012 "OS0302 - 1"-"OS0302-2" 2012年9月

記述言語：日本語出版者・発行元：一般社団法人日本機械学会

Magnesium alloys have special features such as light weight, high specific strength and good reusability. However, information on the flow behavior and formability of magnesium alloys in multi-axial compressive stress conditions is highly limited, nevertheless of their importance for plastic working processes such as forging and extrusion. In the present study, the uniaxial and biaxial compression tests along proportional strain paths were conducted at room and at elevated temperatures, and thus the influence of strain paths and temperature upon mechanical properties and compressive forming limit were discussed. The results revealed that the flow stress scarcely changes with the test temperature in the range from 493 K to 523 K. On the other hand, the compressive forming limit was found to be dependent on the temperature as well as the strain paths.

CiNii Article

CiNii Books

researchmap

J041025 純チタン結晶粒内マイクロピラーの単軸圧縮変形の結晶方位依存性に関する基礎的検討

清水一郎, 岡野翔太朗, 多田直哉

年次大会 : Mechanical Engineering Congress, Japan 2012 "J041025 - 1"-"J041025-3" 2012年9月

記述言語：日本語出版者・発行元：一般社団法人日本機械学会

Titanium is one of materials with hexagonal close-packed structure, in which mechanical twinning often occurs and the plastic behavior becomes rather complicated. In recent years, the compression testing technique of a micropillar fablicated in a grain of metallic material has been developed for the purpose to study the deformation properties of a single crystal structure in a polycrystalline aggregate. In the present study, micropillars with rectangular cross section were fablicated in grains of industrial pure titanium by Focused Ion Beam (FIB) technique. The micro-compression tests were then performed in order to investigate the compressive behavior of single crystal micropillars. It was found that the load-displacement relations obtained by compression tests varied according to the crystal orientation and dimensions of the micropillars. Several traces of mechanical twinning were found to appear on the side surfaces of micropillars after the compression test, when the compressive force was applied in <0001> direction of the titanium grains.

CiNii Article

CiNii Books

researchmap

直流電位差法を用いた微小接合界面損傷の非破壊評価 (電界計測の応用とその新展開(2))

多田直哉

非破壊検査 61 ( 9 ) 452 - 457 2012年9月