利用有限元素法分析碳纖維棒於混凝土中之握裹實驗

Finite Element Analysis on Bonding Test of CFRP Bars inside Concrete

程如君(Ru-Jyun Cheng)

指導教授 ： 李有豐

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2010年)

摘要

本論文將FRP棒替代傳統鋼筋應用於土木構件中，對於FRP棒與混凝土間界面之握裹機制及破壞模式加以討論。本論文提出一握裹界面模型，該模型之控制參數為剪切模數與臨界剪應力，由變位諧和配合材料等向性之條件可推算得剪切模數；利用握裹試驗之極限強度以握裹界面均佈受力之假設推算，可得臨界剪應力。本論文藉由有限元素分析軟體ANSYS，模擬CFRP棒與混凝土，並於其交界區加入界面元素(Interface Element)，以探討FRP棒與混凝土間之力量傳遞與握裹機制。依據本論文之數值模型分析結果顯示，剪應力主要由握裹界面前端均勻承受，然後漸為消散，至握裹界面之後端力量影響已極小，整體握裹剪應力為非均勻分布，故本論文以均佈假設所推算得的臨界剪應力較小，使得本分析能承受之荷載較實際情形少，且較為保守。未來可利用本研究之界面模型，應用於CFRP棒於混凝土之不同構件間(如CFRP梁)，以模擬構件之力學行為。

關鍵字

握裹分析 ； FRP棒 ； 有限元素法

並列摘要

In this paper, the interface model was proposed and the finite element analysis was applied to numerical simulation the bonding test of CFRP bars inside concrete. Two parameters were used in this interface model. Interface shear modulus was obtained from the deformation compatibility between CFRP bars and inner concrete and the isotropic condition. Critical shear stress of interface was calculated with the assumption of the uniform stress distribution condition by the critical tensile strength of CFRP bonding test. Analytical results shows that the distribution of interface shear stress is uniform at the region near by loading location and the shear stress decreased gradually along the bar member. The shear stress was less impacted on the bar end. Comparison of the analytic and test results indicated that the analytical critical strength was conservative cause of the analytical variable stress distribution.
The interface model can not only simulate the transmission of strength between CFRP bars and concrete but also the deboning mechanism. The proposed CFRP bonding interface model in this study is referable for components member behaviors analysis.

並列關鍵字

Bonding analysis ； FRP bar ； Finite Element Method (FEM)

參考文獻

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[37] 張永毅(2006)，碳纖維棒應用於RC梁構件之研究，碩士論文，國立台北科技大學土木與防災技術研究所，台北。

[46] 羅國軒(2007)，纖維棒應用於梁構件力學行為與耐久性之研究，碩士論文，國立台北科技大學土木與防災研究所，台北。

[1] ACI Committee 440.1R-03. “Guide for Design and Construction of Concrete Reinforced with FRP Bars”.

[2] ACI Committee 408, (1991). “State-of-the-Art Report: Bond under Cyclic Load”.