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论文类型：会议论文

发表时间：2008-01-01

收录刊物：CPCI-S

卷号：7

页面范围：1879-1884

关键字：thermal stress; Heterogeneous; thermal cracking; thermal-mechanical coupling

摘要：Thermal stresses induced by thermal mismatch and thermal gradient play an important role in the failure of concrete structures as temperature changes are take into account. The significant differences of thermal expansion coefficients, Young' modulus and Poisson's ratio, occurred between aggregates and mortar, lead to severe thermal or residual stresses which are large enough to break down the concrete. In this paper, a numerical model, named RFPA-Thermal code, is proposed for thermal stress analysis and thermal cracking prediction. The heterogeneity of concrete are take into account in the model by employ the Weibull's distribution law, and damage mechanics is used to model the damage evolution processes. The presented method is easy to predict the location where cracks are most likely to initiate and propagate, even the stress buildup, stress release. and stress transfer in the model as temperature changes. The numerical model is used to predict the crack propagation of thick-wall as it subjected to thermal stress, and the results indicate that as the inner temperature is larger than that of outer, thermal cracks will occurred at the outer-wall firstly and extend gradually into the inner; on the contrary, if the inner temperature is lower than that of outer, cracks will initiated at the inner-wall firstly, and propagate to the outer-wall.