疲劳荷载与水耦合作用下无砟轨道裂纹动态演化过程研究

项目名称： 疲劳荷载与水耦合作用下无砟轨道裂纹动态演化过程研究

项目编号： No.51508121

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： 徐桂弘

作者单位： 贵州理工学院

项目金额： 20万元

中文摘要： 无砟轨道在我国高速铁路中得到了广泛的应用，但以裂纹为主要形式的伤损问题逐步凸显，特别是雨水对裂纹扩展的影响尤为突出，目前国内外对相关问题缺乏系统的研究。本项目拟针对典型无砟轨道裂纹受力及扩展问题，对疲劳荷载作用及雨水浸入条件下，裂纹的动态演化过程进行理论与试验研究。通过万能伺服液压机施加模拟列车疲劳荷载，开展无砟轨道复合试件开裂性状模型试验及混凝土裂纹水压力试验，分析裂纹扩展性态及动水压力作用特性。利用实时全息干涉法、高分辨率数字摄像机与计算机图像处理系统相链接的三位一体化测量系统，连续动态的观测裂纹张开、闭合、扩展与变形交替演化过程。分析带裂纹的无砟轨道结构在不同加载时间段的力学特性，研究微裂隙、微空洞等损伤的产生和演化导致材料性能嬗变机理. 建立疲劳荷载与水耦合作用下无砟轨道裂纹受力与变形计算理论和方法，研究无砟轨道服役状态评估方法。研究成果将为进一步丰富和完善混凝土伤损理论提供参。

中文关键词： 无砟轨道；裂纹；流固耦合；动态演化

英文摘要： The non-ballasted track had been widely used with the massive construction of the high-speed railway in China. The damage issue of non-ballasted track mainly based on the crack was becoming gradually evident, especially the influence of rainwater to the damages. Nowadays there was a lack of the systematic research on the relevant problems at home and abroad.Non-ballasted track composite specimens cracking characteristics test and water pressure test are carried out, after fatigue load is applied by the universal servo-hydraulic machine to simulate the train loads, so the crack growth behavior and hydrodynamic pressure characteristics are analysized.Crack dynamic evolution process such as crack open, closure, growth and deformation, is continuously observed by three integrated measurement system linked with real-time holographic interferometry, high-resolution digital camera and computer image processing system.Analyse the mechanical properties of non-ballasted track structure with cracks at different loading periods, and research the generation and evolution of micro cracks, micro cavity damage，and leading to material properties evolution mechanism.Establish the force and deformation theory and calculation methods of non-ballasted crack under fatigue load and water interaction, and research non-ballasted track service status assessment methods.The research achievements provided reference for enriching and perfecting the theory on the concrete damages.

英文关键词： ballastless track;crack;fluid-solid interaction;dynamical evolution