Strain-Rate Sensitivity on Stress-Strain Behavior of RPC by Modified Inclusion Theory

• Main Authors: Guo yu-ting, 郭昱廷
• Other Authors: Huang-Hsing Pan
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/51959221283141952660

碩士 === 國立高雄應用科技大學 === 土木工程與防災科技研究所 === 96 === This research is to investigate the strain rate effect on the stress-strain curve of RPC composites by using the inclusion theory and the secant moduli. The composite material is examined at the age of 7 days with RPC mortar as the matrix, and three volume concentrations, 1％, 2％ and 3％, of the steel fiber as the inclusion respectively. Strain rates with 5×10^-6/s、5.5×10^-5/s、1×10^-4/s、1×10^-3 /s、1×10^-2 /s and 1×10^-1/s by MTS, and with 2×10^2/s ~1×10^3 /sby SHPB are applied to the materials, respectively. A four-parameter mechanics model in term of the strain rate is proposed to simulate the stress-strain curves of the RPC matrix. From the simulated results of the RPC matrix, the mean-field approach and the secant modulus method are used to simulate the stress-strain relationship of the RPC composites. Results show that dynamic four-parameter mechanics model can be derived from the static mechanics model, and four parameters with K1、K2、η1 and η2 are determined from the experimental stress-stain curves of the matrix simulated the RPC matrix. Meanwhile, the simulated stress-strain curves and the experimental ones are pretty close to the each other in RPC composites with different strain rates at the peak strain 2×10^-3 ~ 3×10^-3. Thus, the proposed approach by combining the inclusion theory and the secant modulus is suitable for predicting the stress-strain relationship of the RPC composites with dynamic different strain rates.