Behavior and Control of Stress Oscillations Induced in Functional Inhomogeneous Plates

2018 Fiscal Year Final Research Report

• Project/Area Number: 26420015
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Shimane University
• Principal Investigator: ASHIDA FUMIHIRO 島根大学, 学術研究院理工学系, 教授 (60149961)
• Project Period (FY): 2014-04-01 – 2019-03-31
• Keywords: 不均質材料平板 / 動的弾性問題 / 動的熱弾性問題 / 応力振動挙動 / 力学的インピーダンス / 応力振動抑制法 / 圧電効果 / 磁性効果

Outline of Final Research Achievements

In this study, an elasto-dynamic problem of an inhomogeneous piezoelectric thin plate subjected to impact pressure was analyzed first and behavior of the stress oscillation caused by the elastic wave propagation was investigated. Obtained results indicate that the mechanical impedance governs whether a compressive steady stress oscillation or an unsteady stress oscillation with tensile stress is induced.
Secondly, electro-elasto-dynamic and thermo-electro- elasto-dynamic problems of inhomogeneous thin plates composed of a piezoelectric material and/or a magnetic material were analyzed, when the plates were subjected to impact pressure or thermal shock. Obtained results illustrate that the stress oscillation induced by the impact pressure decreases when an appropriate electric or magnetic potential is applied to the plate. On the other hand, the thermal stress oscillation induced by the thermal shock attenuates as time advances when an appropriate magnetic filed is applied to the plate.

Free Research Field

材料力学

Academic Significance and Societal Importance of the Research Achievements

本研究では，不均質圧電材料平板に衝撃負荷が作用したとき，危険な引張応力を伴った非定常応力振動が生じることと，力学的インピーダンスが定数になるように平板を設計すると，比較的安全な圧縮性の定常応力振動が生じることを示した．次に，圧電材料や磁性材料で構成された不均質材料平板において，不可避に力学的インピーダンスが変化する場合，電位差，磁位差または磁界の作用によって，危険な非定常応力振動を抑制できることを示した．
これらの研究成果は，独創的で学術的に意義があるとともに，薄膜層で構成されるナノ電子デバイス等では応力振動が破壊要因となるため，応力振動の抑制法の開発は社会的にも意義があると思われる．