钢-聚丙烯混杂纤维混凝土弹塑性损伤本构关系研究

The consitutive model of fiber reinforced concrete material plays a critical role in design and nonlinear analysis of structural behavior, since it directly determines the entire structural performance and failure progress. Therefore, by means of experimental, theoretical and numerical approaches, this project aims to develop the elasto-plastic damage model of steel-polypropylene hybrid fiber reinforced concrete, efforts are made to: (1) considering different fiber parameters in terms of volume fraction, aspect ratio and fiber type, explore the entire spatial damage progress and damage evolution of HFRC under uniaxial and triaxial cyclic loadings, develop the mathematical formulation of the damage constitutive relation of HFRC. (2) reveal the fiber sliding mechanism through fiber pullout test and propose the bond-slip constitutive relation. (3) establish the corresponding failure criterion, fiber sliding criterion and damage evolution law of HFRC. In the mean time, introduce the influence of fiber orienation and distribution on the sliding energy disspation and develop the elasto-plastic damage constitutive model of HFRC within the framework of thermodynamics by coupling the theory of damage and elastoplasticity. This research can lead to a better understanding of essential damage and failure mechanism of HFRC, the outcome is of significance in performance control and safty use of HFRC structures.

纤维混凝土材料的本构关系是其结构性能设计及非线性分析的关键问题之一，它直接影响着纤维混凝土工程结构的整体性态和失效规律。因此，本项目将采用试验研究、理论分析和数值模拟相结合的方法，对钢-聚丙烯混杂纤维混凝土(HFRC)的弹塑性损伤本构关系开展系统地研究，研究内容包括：(1)考虑不同纤维体积率、长径比、类型等影响因素，通过单轴循环抗压、抗拉试验及三轴循环压缩试验，研究HFRC损伤演化规律及损伤机理并建立HFRC损伤本构关系数学表达式；(2)通过纤维拔出试验揭示纤维滑移机理并提出纤维与基体的粘结-滑移关系数学表达式；(3)耦合损伤理论和弹塑性理论，建立HFRC破坏准则、纤维滑移准则及损伤演化法则，同时引入细观纤维方向对粘结滑移能耗的影响，在不可逆热力学框架下构建HFRC弹塑性损伤本构模型。预期成果有助于揭示HFRC材料及结构损伤失效的内在本质，对HFRC结构性态控制及其安全使用具有重要意义。

纤维混凝土材料的本构关系是其结构性能设计及非线性分析的关键问题之一，它直接影响着纤维混凝土工程结构的整体性态和失效规律。因此，本项目将采用试验研究、理论分析和数值模拟相结合的方法，对钢-聚丙烯混杂纤维混凝土(HFRC)的弹塑性损伤本构关系开展系统地研究，研究内容包括：(1)考虑不同纤维体积率、长径比、类型等影响因素，通过单轴循环抗压、抗拉试验及三轴循环压缩试验，研究HFRC损伤演化规律及损伤机理并建立HFRC损伤本构关系数学表达式；(2)通过纤维拔出试验揭示纤维滑移机理并提出纤维与基体的粘结-滑移关系数学表达式；(3)耦合损伤理论和弹塑性理论，建立HFRC破坏准则、纤维滑移准则、损伤演化法则，同时引入细观纤维方向对粘结滑移能耗的影响，在不可逆热力学框架下构建HFRC弹塑性损伤本构模型。预期成果有助于揭示HFRC材料及结构损伤失效的内在本质，对HFRC结构性态控制及其安全使用具有重要意义。