奈米碳管沉積附著對複合材料破壞偵測之應用

Abstract

纖維複合材料是常被應用在航太、汽機車等產業中的材料，由於其破壞機制較傳統金屬材料複雜，因此如何掌握其損傷狀況便為一大重點。常用之非破壞檢測有量測電阻變化的電壓監測法以及內埋布拉格光纖光柵感測器。 本研究對電壓監測法進行了改良，試驗對象為玻璃纖維-環氧樹脂複合材料。將奈米碳管預先附著至玻璃纖維布上，利用不同的附著幾何形狀搭配不同的電極接法，期望使電壓監測法之靈敏度增加，並具有損傷定位能力。此外部分試片也內埋入布拉格光纖光柵，作為輔助佐證電壓不足以反映之破壞。 進行試驗之試片分為方形板材及標準規格試片兩種。板材主要在探討低能量衝擊下的靈敏度改善程度及定位衝擊點，判斷衝擊方向等能力。標準規格試片則進行了為低能量衝擊、循環拉伸、衝擊後循環拉伸等三種試驗，主要探討靈敏度改善程度、定位衝擊點、以及藉由多頻道電壓預測拉伸斷裂處等能力。 實驗結果說明附著碳管之作法可增加電壓監測法之靈敏度，而在定位衝擊點及預測斷裂位置方面，成效不算完美但仍有一定效果，若能加以改善附著之碳管幾何設計及電極接法，應可得到更佳的成效。證實藉由預先附著碳管的作法可使電壓監測法在應用上更加靈活。

Fibre reinforced polymers (FRPs) are materials that are often used in aerospace, automobile and locomotive industries. Its mechanism of fracture is more complicated than traditional metal materials, therefore, how to grasp the damage status is a important point. Nondestructive detection methods that commonly used include voltage monitoring methods and embedded fiber Bragg grating(FBG) sensors The test material used in this study is glass fiber/epoxy resin composite material. We improve the voltage monitoring methods by pre-attaching carbon nanotubes(CNTs) to the glass fiber before vacuum assisted resin transfer molding(VARTM). With different attachment geometries and different electrode connections, we expected to increase the sensitivity of the voltage monitoring method and locate the position of damage. In addition, some of the test pieces are also embedded with FBGs, as an auxiliary evidence for the damage that voltage monitoring methods could not reflect. The test pieces are divided into square plate and standard specification pieces. The purpose of square plate testing is to discuss the improvement of sensitivity under low-energy impact, and also the ability to estimate the impact position and direction. The standard specification test pieces were subjected to low-energy impact, cyclic tensile, and cyclic tensile after impact, mainly to discuss the effect of sensitivity improvement, the ability of impact point locating, and the ability to predict the position of fracture by multi-channel voltage monitoring. The results show that pre-attached CNTs can improve the sensitivity of the voltage monitoring method. In terms of locating the impact point and predicting the fracture position, it works to a certain extent. It is confirmed that the method of pre-attaching carbon tubes can make the voltage monitoring method more flexible in application.