SHCC管的试验研究与结构分析
发布时间：2018-07-24 10:03
【摘要】：聚乙烯醇(PVA)—应变硬化水泥基复合材料(简称SHCC)是目前发展迅速的一种超高延性纤维增强水泥基复合材料,通过在特制水泥砂浆中掺入一定量的PVA纤维制成,在承受拉伸荷载时,表现出多缝稳定开裂和应变硬化特征,从而在许多发达国家的不同领域已经得到了工程应用,但却鲜有SHCC管道方面的研究。本课题在国家863计划——《多基结构材料复合技术及在高压管制造中的应用》(2013AA031306)项目资助下开展SHCC管道的相关研究。本文通过实验手段研究SHCC管道在平压荷载作用下的应变、位移以及裂纹的变化;再通过理论计算SHCC管道的极限承载力及其影响因素,并对SHCC管刚度进行探讨。主要工作如下:(1)开展了SHCC单轴拉伸实验和三支承下的SHCC管平压试验,研究表明,SHCC材料与管环的失效过程大致分为:弹性阶段、开裂阶段、强化阶段和破坏阶段等,在SHCC管底、管腰和管顶等观察到多条细裂纹,与内径相同的普通混凝土管相比,SHCC具有厚度更薄以及承载力更高的优势;(2)建立了SHCC管道平压状态下的力学分析模型,分别以最大压应变和最大弯矩为控制参量计算得出SHCC管的极限承载力,并与测试结果进行了比较,讨论了结构几何尺寸以及材料力学参数对结果的影响,研究表明以最大压应变为控制参数计算极限承载力能较准确的得到SHCC管的极限承载力,此方法中SHCC受压时的极限弹性应变对结果影响最大;以最大截面弯矩为控制参数计算极限承载力时能较准确的反映出SHCC管平压试验的过程,此方法中SHCC的极限拉伸强度对结果影响最大;(3)基于国内外结构管刚柔性的相关理论分析了SHCC管刚度,结果表明:SHCC管在进入开裂阶段后直至最终破坏,其刚度随着管顶荷载的增加,明显下降;本文围绕SHCC管研究展开,对发展新型抗裂混凝土管道将起到推动作用。
[Abstract]:Polyvinyl alcohol (PVA) strain hardening cement matrix composite (SHCC) is a kind of super ductile fiber reinforced cement matrix composite which is developed rapidly at present. It is made by adding a certain amount of PVA fiber into special cement mortar. When subjected to tensile load, it shows the characteristics of multi-joint stable cracking and strain hardening, so it has been applied in many developed countries in different fields, but there is little research on SHCC pipeline. This project is funded by the National 863 Program-"Multi-base structural material Composite Technology and its Application in High pressure Pipe Manufacturing" (2013AA031306) project to carry out research on SHCC pipeline. In this paper, the strain, displacement and crack of SHCC pipeline under the action of flat compression are studied by experimental means, and the ultimate bearing capacity of SHCC pipeline and its influencing factors are calculated theoretically, and the stiffness of SHCC pipe is discussed. The main works are as follows: (1) the uniaxial tensile test of SHCC and the test of SHCC tube under three supports have been carried out. The results show that the failure process of SHCC material and ring can be divided into three stages: elastic stage, cracking stage, strengthening stage and failure stage, etc., at the bottom of the SHCC tube, Many fine cracks have been observed in the tube waist and top of the pipe. Compared with the common concrete pipe with the same inner diameter, SHCC has the advantages of thinner thickness and higher bearing capacity. (2) the mechanical analysis model of SHCC pipeline under the condition of flat pressure is established. The ultimate bearing capacity of SHCC pipe was calculated by using the maximum compressive strain and the maximum bending moment as control parameters, and compared with the test results. The effects of structural geometry and mechanical parameters of materials on the results were discussed. The results show that the ultimate bearing capacity of SHCC tube can be calculated accurately by using the maximum compressive strain as the control parameter. In this method, the ultimate elastic strain of SHCC under compression has the greatest influence on the results. When the ultimate bearing capacity is calculated with the maximum bending moment as the control parameter, it can accurately reflect the process of the SHCC pipe flat pressure test. In this method, the ultimate tensile strength of SHCC has the greatest influence on the results. (3) the stiffness of SHCC tubes is analyzed based on the theory of structural flexibility at home and abroad. The stiffness of the pipe decreases obviously with the increase of the load on the top of the pipe, and the research on the SHCC pipe is carried out in this paper, which will promote the development of the new crack resistant concrete pipeline.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332
[Abstract]:Polyvinyl alcohol (PVA) strain hardening cement matrix composite (SHCC) is a kind of super ductile fiber reinforced cement matrix composite which is developed rapidly at present. It is made by adding a certain amount of PVA fiber into special cement mortar. When subjected to tensile load, it shows the characteristics of multi-joint stable cracking and strain hardening, so it has been applied in many developed countries in different fields, but there is little research on SHCC pipeline. This project is funded by the National 863 Program-"Multi-base structural material Composite Technology and its Application in High pressure Pipe Manufacturing" (2013AA031306) project to carry out research on SHCC pipeline. In this paper, the strain, displacement and crack of SHCC pipeline under the action of flat compression are studied by experimental means, and the ultimate bearing capacity of SHCC pipeline and its influencing factors are calculated theoretically, and the stiffness of SHCC pipe is discussed. The main works are as follows: (1) the uniaxial tensile test of SHCC and the test of SHCC tube under three supports have been carried out. The results show that the failure process of SHCC material and ring can be divided into three stages: elastic stage, cracking stage, strengthening stage and failure stage, etc., at the bottom of the SHCC tube, Many fine cracks have been observed in the tube waist and top of the pipe. Compared with the common concrete pipe with the same inner diameter, SHCC has the advantages of thinner thickness and higher bearing capacity. (2) the mechanical analysis model of SHCC pipeline under the condition of flat pressure is established. The ultimate bearing capacity of SHCC pipe was calculated by using the maximum compressive strain and the maximum bending moment as control parameters, and compared with the test results. The effects of structural geometry and mechanical parameters of materials on the results were discussed. The results show that the ultimate bearing capacity of SHCC tube can be calculated accurately by using the maximum compressive strain as the control parameter. In this method, the ultimate elastic strain of SHCC under compression has the greatest influence on the results. When the ultimate bearing capacity is calculated with the maximum bending moment as the control parameter, it can accurately reflect the process of the SHCC pipe flat pressure test. In this method, the ultimate tensile strength of SHCC has the greatest influence on the results. (3) the stiffness of SHCC tubes is analyzed based on the theory of structural flexibility at home and abroad. The stiffness of the pipe decreases obviously with the increase of the load on the top of the pipe, and the research on the SHCC pipe is carried out in this paper, which will promote the development of the new crack resistant concrete pipeline.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332
【参考文献】
相关期刊论文 前5条
1 侯利军;张秀芳;徐世p，
本文编号：2141021
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