內埋回收碳纖維紙於玻纖複材效果之分析

Abstract

玻璃纖維因為高強度及良好的耐化學性，常常被拿來製作複合材料。本研究主要探討再加入回收碳纖維紙後，機械性質在拉伸及疲勞中有何異同。與環氧樹脂混合後的奈米碳管作為基材可以利用其導電的特性作為監測的方式，在高溫低濕，高溫高濕兩種不同的環境中，分析濕熱老化對複合材料的影響程度，並且與未處理過的試片進行比較。 研究發現加入碳纖維紙後拉伸強度上升5%，疲勞壽命則是延長了96%，並且高溫高濕下降的強度從原本46%降低成36%，進而證實其對機械性質有增強的效果。除了在疲勞方面純玻璃纖維電壓變化較顯著外，其餘在拉伸實驗或是高溫高濕45天電阻監測期間也都發現碳纖維紙將破壞情形反映在電壓上的能力比較優秀。值得一提的是在拉伸及疲勞中大部分加入回收碳纖維紙的試片電壓都會有先下降再上升的趨勢，推測先是純玻纖卸載時受內部壓應力電壓才下降，後來主導電壓的碳纖維紙開始受損造成後續的上升。未來可以朝不同的天數及濕熱老化後疲勞這兩個方向去努力，最終目標能清楚了解加入回收碳纖維紙的優劣。

Due to the high tensile strength and the excellent ability to resist the chemistry, glass fiber is usually used to fabricate composites. This research aims to investigate mechanical similarities and differences between both kind of material in tensile and fatigue test, after adding the recycled carbon fiber paper(RCFP). Utilizing the electrical method to monitor the damage of composites after mixing up epoxy resin and carbon nanotubes, which enable the material to be conductive. Under the high temperature low humidity and high temperature with high humidity, these two different circumstances. We are trying to analyze the extent of influences caused by hygrothermal aging and compare the properties with virginal ones. Research found the tensile strength with recycled carbon fiber paper increase by 5%, fatigue life extend 96% and the tensile strength drop from 46% to 36% after immersed for 45 days, this result confirms the strengthen effect on mechanical properties when adding RCFP.Apart from the fact voltage change of original composites(without RCFP added) are more apparent on the fatigue test, the added ones exhibit better behaviors no matter on the tensile test or in the 45 days-electrical resistance-monitoring under the immersing condition. That is to say, RCFP perform well on the aspect of representing the damage to the voltage change. Interestingly, we can observe a phenomenon that voltage of specimen with RCFP added drop first then increase up, it occurs both on tensile and fatigue test. It is suggested initial voltage drop is due to the internal stress of glass-fiber when unloaded, then damage of RCFP(dominate voltage in composites) cause the voltage increment afterward. In the future follower can work on two ways, different duration and fatigue test after hygrothermal aging. The ultimate goal is to appreciate more clearly on the pros and cons about RCFP added to the GFRP.