SIMPLIFIED INVERSE METHOD FOR DETERMINING UNIAXlAL TENSILE σ-ε CURVE OF STRAIN HARDENING CEMENTITIOUS COMPOSITES (SHCC)
High brittleness of cementitious composites is the primary causations of cracking and performance deteriorated of concrete structures, lntuitionistic behavior of brittleness is the soften stage of the stress and strain curve. High modulus polyvinyl alcohol fiber can improve the ductile capability of cementitious composite. Multi-microcracks and strain hardening of SHCC in tensile test and bending test made the curve different form normal cementitious composites. The σ-ε curve may be determined directly in uniaxial tension tests. Unfortunately, these tests are technically difficult,expensive and time-consuming. Bending tests are a technical alternative. However, for determining the σ-ε curve on the basis of bending test results inverse analyses of the experiments are required. The analyses by using an evolutionary algorithm include simulations of the deformation and fracture processes in the specimen and an iterative fitting of the numerical results to the experimental ones.The mechanical model used for the inverse analysis in CONHARD software is based on non-linear axial members (multi-layer model) in the inner region of maximum moment and a linear-elastic Finite Element model for the side regions. The linear-elastic part is pre-analyzed and replaced by a macro-element. The experiments are simulated numerically with an assumed hardening behavior, I.e.an assumed σ-ε curve. In an iterative process, the hardening curve is modified in order to obtain the best fit of the numerical results to the experimental data. At last the non-linear axial members incorporate a multi-linear stress-strain curve with strain hardening will be obtained. Results show that numerical simulation fit the experimental curves well.
Strain hardening Cementitious composites Polyvinyl alcohol (PVA) fiber-ε curve Inverse analysis
Li Tian Jing-Ru Chen Tie-Jun Zhao Song Gao
School of Civil Engineering, Qingdao Technological University, Qingdao 266033, P.R. China Xian Univ School of Civil Engineering, Qingdao Technological University, Qingdao 266033, P.R. China
国际会议
第十届国际结构工程青年学者研讨会(The Tenth International Symposium on Structural Engineering for Young Experts)
长沙
英文
1826-1829
2008-10-19（万方平台首次上网日期，不代表论文的发表时间）