高应变率下超轻高强水泥基复合材料的多尺度研究：材料破坏、本构、纤维与基体的相互作用

项目名称： 高应变率下超轻高强水泥基复合材料的多尺度研究：材料破坏、本构、纤维与基体的相互作用

项目编号： No.51508294

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 建筑环境与结构工程学科

项目作者： 刘雪梅

作者单位： 青岛理工大学

项目金额： 20万元

中文摘要： 最新研制的超轻高强水泥基复合材料（ULCC）可用于需要承受可能的极端荷载的比如抗冲击或浮动结构体等结构设施。然而，材料在高应变率荷载下的动力响应还仍未知。因此，该项目主要结合实验和理论，配合数值模拟对以下几个方面进行深入研究。(1)在微观尺度上-纤维/水泥基体的相互作用对微观力学特性的影响，微观力学模型将用于分析纤维/基体的相互作用对宏观材料的影响。(2)宏观尺度上-高应变率对ULCC的直接拉伸和受压本构的影响及破坏机理，聚乙烯及钢纤维，基体强度等对本构的不同影响。(3) 结合数值模型进行参数分析，提出该复合材料在高应变率下的本构模型以及预测材料的动态强度增强因子（DIF）的模型。理论模型还将用于修正CEB-FIP模型理论，以建立基于动力荷载准则下得结构设计及材料优化。该项目为ULCC在石油和天然气行业相关的海工结构中的应用提供理论依据。

中文关键词： 纤维混凝土；耐久性；混凝土损伤

英文摘要： The recently developed ultra-lightweight cement composite (ULCC) has great potential to be used for floating structures which require withstanding likely extreme loadings such as impact or blast. However, such dynamic properties are still missing. This project presents a combined experimental, theoretical and also numerical investigation on the high strain rate effects on both micro-scale fiber/matrix interaction and composite-scale mechanical properties of ULCC. The properties of ULCC include the direct-tensile and compression behavior under high strain rates, as well as the failure mechanisms. Micro-mechanics model will be used to understand the fiber/matrix interactions. Constitutive models of ULCC will be established based on the experimental results and parametric study through the validated finite element models through the experiments. Theoretical models will also be proposed to predict the both tensile and compressive dynamic increase factor (DIF) of ULCC, used to amend CEB-FIP code and provide bases to support studies in infrastructures to sustain dynamic loadings. This project will provide in-depth understanding of both micro- and composite-scale responses of ULCC under various high strain rates loadings, and develop a new modelling foundation to explore its dynamic performance. Providing knowledge beyond the experimental measurements, this project will support studies into analysis and design of floating structures and other infrastructures under extreme loadings.

英文关键词： fiber reinforced concrete;durability;failure mechanism;strain rate effects;numerical simulation