本研究主要探討蜂巢相關材料之彈塑性變形行為，由於蜂巢相關材料之主要變形機制乃其微觀桿件之撓曲變形，因此，採用一細長梁加以模擬微觀桿件，假設其承受不同載重與邊界束制，理論推導及數值分析此細長梁及蜂巢相關材料受力及變形行為。利用有限元素套裝軟體ABAQUS，建立不同幾何條件之數值分析模型，假設組成固體材料為一完美塑性材料，配合適當邊界束制及施力條件，進行其彈塑性行為之數值分析。然後，理論推導一細長懸臂梁，當進入塑性變形後之折減勁度，轉換成共軛梁上之放大載重，求取此共軛梁之彎矩，亦即原細長懸臂梁之垂直位移。接著，將數值分析結果及理論推導公式中之施力變形關係，進行正規化及無因次化處理，進而獲得一致施力變形關係，因此，可使用理論推導所得之關係公式，描述微觀桿件彈塑性行為，最後，進一步將微觀桿件之施力變形關係，透過物理尺度轉換，求得整體蜂巢相關材料的彈塑性應力應變關係。

SUMMARY
The elasto-plastic behavior of honeycomb-like materials with different relative densities is analyzed theoretically and numerically. It is assumed that the solid material from which honeycombs are made is linearly elastic-perfectly plastic and the bending of cell edges is their dominant deformation mechanism. The transition from initial yielding to full plasticity of cell edges in honeycomb-like materials is of concern and studied here. An expression for describing the force-deformation curve of the transition is obtained theoretically by using the conjugate beam method and then verified numerically by using the finite element package ABAQUS. The elasto-plastic deformation behaviors of honeycomb-like materials with four different types of cell-edge geometries, such as curved cell-edge, variable-thickness cell-edge and straight uniform-thickness cell-edge, are first analyzed and then compared to each other. As a result, a theoretical formula is found and can be utilized to describe the elasto-plastic behavior of honeycomb-like materials.

Keywords: honeycomb-like material, perfectly-plastic, elasto-plastic deformation, finite element numerical analysis, conjugated beam method.

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