PVA纤维增强水泥基复合材料性能试验及梁柱节点数值模拟

发布时间：2018-05-05 21:26

本文选题：高延性纤维增强水泥基复合材料 + 准应变硬化　；参考：《兰州理工大学》2013年硕士论文

【摘要】：混凝土材料是目前世界上应用最广泛、用量最大的建筑材料,虽然混凝土材料具有许多优异性能,但是也存在着脆性大、易开裂和抗拉强度低等缺点,使用于实际工程中往往会导致结构的破坏,影响建筑物的正常使用。在混凝土中掺加纤维有利于克服上述缺点,提高混凝土的抗弯强度、抗拉性能、抗剪强度,增强混凝土的抗冲击性、韧性、延展性,改善混凝土的抗渗性、耐磨损性以及抗裂性,提高混凝土的耐久性,从而达到提高建筑物的质量和使用寿命的目的。高延性纤维增强水泥基复合材料(Engineering Cementitious Composites,简称ECC),属于新型高性能纤维混凝土材料,其在直接拉伸作用及弯曲作用下均表现出多缝开裂和准应变硬化的典型特征,其极限拉伸应变能稳定地达到3%以上,裂缝宽度保持在100μm左右。它以高延性和优异的耐久性渐渐被人们重视,在实际工程中具有广泛的应用前景。美国、欧洲及日本等发达国家已将ECC应用到实际工程中,而且取得了很好的应用效果,但是在国内,关于ECC的研究才开始不久。本论文根据国内外ECC的科研结果,用聚乙烯醇(Polyvinyl Alcohol,简称PVA)纤维作为ECC的增韧材料,对PVA-ECC进行了工作性能、抗弯性能、抗压性能试验,在此基础上对PVA-ECC梁柱节点进行了数值模拟,主要工作有以下几个方面： 1.对PVA-ECC拌合物进行了工作性能研究,并对PVA-ECC棱柱体试件进行了抗折试验,利用抗压试验研究PVA-ECC棱柱体试件和立方体试件的抗压性能,观察其破坏形态。 2.利用四点弯曲试验研究PVA-ECC梁、板试件的弯曲性能,观察PVA-ECC试件受弯时的准应变-硬化及裂缝开裂形态的特征,通过试验结果,评价PVA-ECC梁、板试件的抗弯性能,计算构件的弯曲韧性指标。 3.利用ABAQUS软件进行模拟,分析了PVA-ECC高延性对梁柱节点受弯试件在水平往复荷载作用下滞回性能的影响；并与普通混凝土梁柱节点受弯试件进行了比较,分析了两者之间变形能力、刚度退化及耗能的不同。
[Abstract]:Concrete materials are the most widely used and used building materials in the world at present. Although concrete materials have many excellent properties, they also have some shortcomings such as high brittleness, easy cracking and low tensile strength. Use in practical engineering will often lead to structural damage, affecting the normal use of buildings. Adding fiber to concrete can overcome the above disadvantages, improve the flexural strength, tensile strength, shear strength, impact resistance, toughness and ductility of concrete, and improve the impermeability of concrete. The wear resistance and crack resistance of concrete can improve the durability of concrete so as to improve the quality and service life of buildings. Engineering Cementitious composites (Ecce), a new type of high performance fiber reinforced concrete material, shows typical characteristics of multi-joint cracking and quasi-strain hardening under direct tensile and bending action. The ultimate tensile strain is over 3% and the crack width is about 100 渭 m. Because of its high ductility and excellent durability, it has been paid more and more attention, and has a wide application prospect in practical engineering. Developed countries such as America, Europe and Japan have applied ECC to practical projects, and achieved good results. But in China, the research on ECC has only begun soon. In this paper, based on the research results of ECC at home and abroad, polyvinyl alcohol Alcohol (PVA) fiber was used as toughening material of ECC, and the performance, bending and compressive properties of PVA-ECC were tested. On the basis of the experiments, the joint of PVA-ECC Liang Zhu was numerically simulated. The main tasks are as follows: 1. The working performance of PVA-ECC mixture was studied, and the flexural test of PVA-ECC prism specimen was carried out. The compressive properties of PVA-ECC prism specimen and cube specimen were studied by compression test, and the failure mode was observed. 2. The flexural properties of PVA-ECC beams and plate specimens were studied by four-point bending test. The characteristics of quasi-strain-hardening and crack cracking of PVA-ECC specimens were observed. The flexural properties of PVA-ECC beams and plate specimens were evaluated by the test results. The flexural toughness index is calculated. 3. The influence of high ductility of PVA-ECC on the hysteretic behavior of Liang Zhu joints under horizontal reciprocating load is analyzed by using ABAQUS software, and the deformation capacity of Liang Zhu joints under horizontal reciprocating load is analyzed by comparing with the flexural specimens of ordinary concrete Liang Zhu joints. Stiffness degradation and energy dissipation are different.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528.572

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