- 學位論文
碳纖維水泥複合材料受力應變與電阻特性之探討
Investigation of Electrical Resistance Characteristics of Carbon Fiber Cement Composite Subject to Stress and Strain
摘要
本文探討智慧型材料CFRC受力時與電阻產生相對應之線性變化，且具有感測應變之能力，未來可應用在結構監測之研究。CFRC進行量測電阻時，內部電流流動在初始階段會不穩定，此時進行受力電阻量測會有較大誤差，倘若應用電阻線性變化率去做一個量測判斷，會有較清楚的量測規則，之後受力階段，詴體內部產生微裂縫時，碳纖維與砂漿產生鍵結力，致使CFRC電阻變化-應變之線性關係，在破壞階段時，電阻變化會有一個跳躍點，給予預警的破壞機制，藉此監測和預警結構體是否產生裂縫與達到破壞。藉由CFRC電阻改變與探討結構裂縫之情況，把感測、致動和資訊等三種功能整合於一體，發展成smart CFRC paste 之智慧型材料（smart material），未來將strain paste sensor 結合於結構體，達到低成本與易量測等優勢進而達到耐震、預防和監測之效果。 為了建立CFRC之基本力學行為，以利後續分析與實際應用，本研究進行了兩個主要的力學行為詴驗:抗壓詴驗、直接拉力詴驗，並於進行詴驗的過程中量測其電阻的變化，並對詴驗過程中之現象加以探討，一方面建立其基本性質，另一方面驗證先前理論模型的正確性，期待能在後續應用於實際結構物的量測。 實驗結果顯示:本研究之配比可以使得碳纖維分散均勻，且僅需要0.2% vol.碳纖維添加率就可以達到降低電阻率的目標。並由抗壓詴驗結果可以發現，材料於受壓時的電阻變化很明顯，28天齡期最高可以達到基礎電阻的15%左右，且Gauge factor會隨著齡期上升而增加，這代表材料會隨著齡期的上升而提高對感知應變的敏感性，可見本研究將水泥基材改為RPC確實可以提高導電率，有別於文獻所使用的一般砂漿。
並列摘要
This paper discusses the intelligent material with the CFRC force corresponding to the resistance produces a linear change, and possessed the ability to measure strain felt, can be applied to the future of research in structural monitoring. CFRC resistance measurements carried out, the internal current-current instability in the initial stage, this time conducted by the force resistance measurement error will be larger, if the application rate to do a linear change in resistance measurements to determine, there will be more clearly The measurement rules, then the force phase, Wei body internally generated micro-cracks, the generation of carbon fiber and mortar bonding force, resulting in resistance changes CFRC - The linear relationship between strain in the damage phase, the resistance changes there will be a jump point, give early warning of the failure mechanism, structure monitoring and early warning to whether to produce cracks and damage. Resistance to change by CFRC and the circumstances of structural cracks, the sensors, actuators, and information integration, three functions in one, into the intelligent smart CFRC paste materials (smart material), the future will strain paste sensor combination in structure to achieve cost advantages with trading volume and thus achieve the seismic testing, prevention and monitoring of results. In order to establish CFRC basic mechanical behavior, in order to facilitate subsequent analysis and practical application, this study conducted two major mechanical behavior Wei test: compressive Wei inspection, direct pull Wei inspection, and was conducted Wei inspection process of measuring its resistance changes, and Wei inspection process of the phenomenon to be explored, on the one hand the establishment of its basic nature, the other hand, verify the correctness of the previous theoretical model, looking forward to the follow-up used in the actual structure of the measurement. The results showed that: the ratio of this study can be made of carbon fiber distributed evenly, and only need 0.2% vol. Rate can add carbon fiber to reduce resistivity targets. By the compressive test results can be found in Wei, material changes in the resistance when the pressure is obvious, the maximum period of 28 days of age up to about 15% of base resistance, and the Gauge factor will increase with rising age, which represents the material will rise with age and increase the perception of strain sensitivity, this study shows that the cement substrate to RPC can indeed improve the electrical conductivity, different from the literature used by the general mortar.