超弾性性は,臨界の長さスケールのダイナミック・フラクチャーを支配する
Markus J Buehler1, Farid F Abraham, Huajian Gao
1Max Planck Institute for Metals Research, Heisenbergstrasse 3, 70569 Stuttgart, Germany.
Nature
|November 14, 2003
まとめ
線形弾性理論は,亀裂の先端の断裂動態を捉えることができない. 大規模なシミュレーションでは,超弾性,または大ストレスの弾性があり,変形ゾーンが臨界エネルギー長度スケールに達すると,断裂速度が支配されます.
科学分野:
- 固体力学 固体力学とは
- マテリアルサイエンス 材料科学
- 計算物理学の物理
背景:
- 材料の弾力性はしばしば変形によって変化します.
- 線形弾力性は恒定の弾性モジュールを仮定し,無限微小の変形のみに適しています.
- 既存の破裂理論は,クラック先の大きな変形にもかかわらず,しばしば線形弾性に依存しています.
研究 の 目的:
- 骨折ダイナミクスにおける大張力弾性 (超弾性) の役割を調査する.
- 線形弾力性が骨折現象をモデル化するのに十分であるかどうかを判断する.
- 裂け目先でのエネルギーフルースの特徴的な長さスケールを導入し,分析する.
主な方法:
- 大規模な原子学的シミュレーション.
- 大株における弾性行動の分析.
- 裂け目の先付近のエネルギーフルースの特徴.
主要な成果:
- 超弾性性は,骨折のダイナミクスに大きな影響を与える.
- 線形弾性理論は,骨折を完全に説明するには不十分である.
- 特徴的なエネルギー長さスケールが特定されました.
- 局所的な超弾性波速は,超弾性ゾーンがこのスケールに近づくときのクラック速度を支配する.
結論:
- 超弾性性は,骨折力学を理解するために極めて重要です.
- 正確な骨折予測には,大きなストレスの効果を組み込んだ高度なモデルが必要です.
- 特定された長さスケールと波速は,クラックの伝播に関する新しい洞察を提供します.
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