Development of practical evaluation method of random-incidence absorption coefficient of building materials

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04460
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 23020:Architectural environment and building equipment-related
• Research Institution: Oita University (2020); The University of Kitakyushu (2018-2019)
• Principal Investigator: Okamoto Noriko 大分大学, 理工学部, 准教授 (00452912)
• Co-Investigator(Kenkyū-buntansha): 富来 礼次 大分大学, 理工学部, 教授 (20420648) ; 大鶴 徹 大分大学, 理工学部, 客員教授 (30152193)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 吸音率 / 建築材料 / in-situ測定 / ランダム入射 / アンサンブル平均

Outline of Final Research Achievements

In this study, the authors proposed a method to obtain an approximate value of random incidence absorption coefficient from the value obtained by sound absorption measurement method of materials using ensemble averaging, namely EA method. Specifically, the statistical absorption coefficient using the normal surface impedance of material obtained by EA method is calculated. The correlation coefficient between the statistical absorption coefficient by EA method and the absorption coefficient by the reverberation room method was 0.98, and values by EA method showed a higher correlation with the reverberation absorption coefficient compared to the impedance tube method. Therefore, the proposed method provided results suggesting the predictability of the random incidence sound absorption coefficient.

Free Research Field

建築環境・設備

Academic Significance and Societal Importance of the Research Achievements

提案手法は一部の研究機関のみに設置されている残響室等の音響実験室を必要としないため，従来の残響室法に比べ，飛躍的にランダム入射吸音率の取得が容易になると考えられる．これまで吸音材料の開発は主に建材メーカーや音響の研究者によって行われてきたが，建築設計者や建築材料の研究者にとっても比較的身近な存在になる可能性があり，既存の材料を組み合わせた意匠性・吸音性の優れた内装仕上げや力学的性能に加え環境的性能も良好な多機能型材料など，健康で文化的な豊かな生活につながる技術開発の一助になると考えられる．