相較於架構較完整、研究較為深入的三相地震超材料，二相結構雖亦具備一定程度的能量消散能力，但目前相關探討仍相對零散，缺乏系統性分析與理論整合。為提升二相結構於實務應用上的可行性，本文旨在釐清其可能呈現之幾何型態、主要影響參數所引發的效應，以及與三相結構在等效模數上的差異，和過去研究不同，也拓展分析二相不同模態之行為，如轉動及軸向移動等。因此本研究參考最近研究的相關成果，將二相材料歸納為兩類結構型態：其一為「內軟外硬」結構，內核由柔軟材料構成，外層為剛性基材；其二為「內硬外軟」結構，則以剛性內核搭配具彈性的基材。本文透過解析解推導與有限元素模擬，建立二相結構與三相模型之間的幾何轉換關係，並從理論角度探討各模態下局部共振頻率及帶隙變化之原因。接著本文亦分析在常見地震超材料尺度與材料條件下，兩種二相結構於不同模態所產生的帶隙範圍，並利用半全域模擬方法探討其對縱波與剪切波之衰減效果。根據模擬與理論結果，進一步探討如何透過幾何與材料參數調整以強化二相結構之消能能力，並指出可能面臨的實務限制。
綜合而言，本文透過理論與模擬方法展示了二相圓柱超材料在地震波控制上的應用潛力。然而若欲達到可媲美甚至超越三相結構之消能效果，往往需倚賴特定極端材料性質與幾何尺度，導致其設計彈性與材料選用受到限制。此亦為未來二相地震超材料應用與設計上亟需克服的挑戰。

Compared to the well-developed three-phase seismic metamaterials, two-phase structures also possess wave attenuation capability but have received less systematic attention. This study aims to clarify the geometric configurations, key influencing parameters, and differences in equivalent modulus between two- and three-phase designs. Unlike previous research, it further extends the analysis to multiple vibration modes, including rotational and axial motions. Two typical two-phase types are considered: soft-core–hard-matrix and hard-core–soft-matrix structures. Analytical derivations and finite element simulations are employed to establish the geometric transition between two- and three-phase models and to investigate the origins of local resonance and bandgap formation under various modes. The bandgap ranges and attenuation effects for longitudinal and shear waves are evaluated under typical seismic metamaterial scales using semi-global simulations. Results demonstrate the potential of cylindrical two-phase metamaterials in seismic wave control. However, achieving comparable performance to three-phase systems often requires extreme material properties or geometric conditions, limiting design flexibility. These findings highlight both the application potential and the challenges that must be addressed for the practical deployment of two-phase seismic metamaterials.

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