本計畫採用 Biot 理論推導位移模型之頻域多孔彈性介質元素及多孔彈性樑及板之 彎曲元素。並以有限元素頻域分析與動態實驗探討二維多孔彈性介質與多孔彈性介質耦 合、多孔彈性樑與二維多孔彈性介質耦合、三維多孔彈性介質與多孔彈性介質耦合、多 孔彈性板與三維多孔彈性介質耦合之脈衝響應。並藉由孔洞率的調整，據以探討各式耦 合問題。 計畫期以兩年時間完成多孔彈性介質/樑/板耦合之脈衝響應有限元素頻域分析與動 態實驗驗證。第一年度將應用多孔彈性樑與板之彎曲振動方程組推導頻域位移模型之多 孔樑與板之彎曲元素。並建構有限元素頻域耦合分析探討二維多孔彈性介質與多孔彈性 介質耦合、多孔彈性樑與二維多孔彈性介質耦合系統於邊界限制、材料參數變異下受脈 衝激振之振動與聲響行為。也將透過孔洞率改變分析探討各式結構與聲場耦合問題。實 驗將規劃建立小型聲響箱、製作夾具、及設計大尺寸阻抗管提供振動與聲場聲響結果比 較驗證。 第二年度計畫將以三維多孔彈性介質與多孔彈性介質耦合、多孔彈性板與三維多孔 彈性介質耦合系統為研究重點。探討耦合系統於邊界限制及材料參數變異下受點脈衝和 均佈脈衝後之振動與聲響行為。將完成多孔彈性介質頻域三維六面體元素以及數值降階 技術增進運算效率。除驗證相關案例之分析結果外，也將應用聲響箱及大尺寸阻抗管進 行振動與聲響量測結果比較驗證。本計畫完成之耦合系統有限元素頻域分析程式與試驗 能量，將可提供業界精確且同步的掌握結構振動與聲場聲響行為，達到設計品質提昇之 目的。 In this project, Biot theory is applied to derive the frequency-domain stiffness matrixes of poroelastic medium element and poroelastic beam as well as plate bending elements based on displacement model. The finite element frequency-domain analyses and dynamic experiments will be applied to explore the impulse responses of two-dimensional poroelastic medium and poroelastic medium coupling, poroelastic beam and two-dimensional poroelastic medium coupling, three-dimensional poroelastic medium and poroelastic medium coupling, poroelastic plate and three-dimensional poroelastic medium coupling problems. By adjusting the porosity of the poroelastic medium and structures, the impulse responses of various types coupling problems may as well be explored. The finite element frequency-domain analyses and dynamic experimental verifications of the impulse responses of poroelastic media/beam/plate coupling systems will be accomplished in this project. In the first year, based on the derived poroelastic beam and plate bending vibration equation sets, the frequency-domain stiffness matrixes of bending elements will be derived. Subsequently, the two-dimensional finite element frequency-domain coupling analyses will be established to study the impulsive vibration and acoustic behaviors of poroelastic medium/medium, poroelastic beam/medium coupling systems influenced by the variations of boundary restrains and material properties. Through the change of porosity, various types of structure/acoustic coupling problems will also be studied. In order to provide vibration and acoustic experimental results for comparisons, a small acoustic chamber and fixtures will be made and a large-scale impedance tube will be designed. In the second year, the efforts of the project will focus on the impulse responses of three-dimensional poroelastic medium/medium and poroelastic plate/medium coupling systems. The influence of boundary restrains and material properties on the vibration and acoustic behaviors of coupling systems under impulsive point or distributed loadings will be examined. In the study, the three-dimensional frequency-domain poroelastic medium hexahedral element as well as the approaches to the system matrix bandwidth reduction for enhance the efficiency of analysis will be achieved. Besides the explorations of impulsive responses of other related structure/acoustic coupling problems, the acoustic chamber and the large-scale impedance tube will be used for experimental validations. The finite element frequency-domain analyses and experimental techniques developed can be rapidly applied in every aspect of poroelastic media/beam/plate coupling systems.