混凝土非线性徐变和损伤耦合及徐变破坏机理研究

项目名称： 混凝土非线性徐变和损伤耦合及徐变破坏机理研究

项目编号： No.51479013

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 水利工程

项目作者： 郑丹

作者单位： 重庆交通大学

项目金额： 84万元

中文摘要： 准确分析混凝土在长期持续荷载下的变形性能，提供准确的混凝土材料力学性能参数，是大坝等大型混凝土结构全寿命周期设计和安全评价的基础。承受长期持续荷载的混凝土材料抗力和标准试验中有所差异，而造成这一差异的本质原因是混凝土材料在长期持续荷载下会发生徐变，材料损伤和徐变的耦合会使徐变体现出一定的非线性，高持续荷载下损伤和徐变的耦合会加速材料的损伤，导致混凝土发生破坏。因此，本项目拟通过分析长期荷载下混凝土徐变导致应变能的累积和微裂纹表面能之间的相互转化关系，阐明混凝土等脆性材料的微裂纹扩展演化规律与徐变变形相互影响的规律，研究损伤和徐变的耦合机理，分析长期持续荷载下混凝土的非线性徐变变形性能，揭示高持续荷载下混凝土发生徐变破坏的原因；分析影响混凝土徐变破坏的因素；为真实工作环境中的混凝土重大混凝土结构分析和设计提供试验和理论依据。

中文关键词： 混凝土；徐变；损伤；破坏

英文摘要： Analyzing concrete properties under sustained loading and providing precise mechanic parameters for concrete is the base of structures design and safety evaluation for concrete structures. Concrete structures will suffer long-term sustained loading under service. It is shown by the present research that concrete will exhibit nonlinear creep deformation behavior under high sustained loading and will fail if the sustained loading is high enough. The basic reason of concrete nonlinear creep and creep failure is coupled effect of concrete damage and creep. In the project, the nonlinear creep deformation behavior of concrete under sustained loading will be analyzed at the base of damage mechanics and the coupled effect of surface energy and strain energy of concrete under long-term loading will be researched. The coupled effect of creep deformation and micro-crack evolution in concrete will be analyzed and the reason of why concrete creep failure happen will be discussed along with the factor influence tertiary failure. At the base of experimental and theoretical results, the constitution of concrete under long-term sustained loading will made, which can provide experimental and theoretical guidance for design and safety evaluation of massive concrete structures.

英文关键词： concrete;damage;creep;failure