GFRP筋异强混凝土简支梁力学性能研究

发布时间：2018-04-19 09:42

本文选题：GFRP筋 + 异强混凝土　；参考：《东北石油大学》2017年硕士论文

【摘要】：随着高强混凝土的发展,高强混凝土已逐渐被应用于土木工程结构中。高强混凝土由于其变形能力较差、易开裂等缺点使得高强混凝土构件在抗裂性与延性方面存在一定的缺陷,至使高强混凝土的应用受到了一定限制,同时,因构件受拉区配置的高强混凝土抗压性能没有得到充分利用会造成材料的浪费。若仅在工程结构构件的关键部位采用高强混凝土,其它部位仍采用普通混凝土,则可充分利用高强混凝土抗压强度高,普通混凝土经济性好的优势,实现二者的有机结合。基于此,本文构建了受压区采用高强混凝土、受拉区采用普通混凝土,受拉筋采用GFRP筋的异强混凝土受弯构件,即可充分利用受压区高强混凝土抗压强度高的特点,又可发挥受拉区GFRP筋轻质高强耐腐蚀等优良特性,且可避免全截面使用高强混凝土所造成的材料浪费。在试验验证的基础上开展该类简支梁的力学性能数值分析,获得不同参数对该类梁抗弯承载力和刚度的影响规律,建立了该类梁的正截面抗弯承载力和刚度计算公式,最后给出该类梁相关的设计建议,为相关技术规程和实际工程应用提供技术支撑。鉴于目前国内外对此类构件的研究较少,本文开展以下4个方面的工作:1.基于ABAQUS有限元软件建立10根配筋梯度混凝土简支梁和FRP筋混凝土简支梁的有限元模型,获得10个试件在竖向静力作用下的荷载-位移曲线,与已有的相关试验数据进行对比,验证了本文建模方法的合理性,提出适用于此类梁的建模方法。2.开展竖向静力荷载作用下28根异强混凝土简支梁扩展参数数值仿真分析,探索异强混凝土简支梁受压区的混凝土强度等级、受拉区GFRP筋配筋率、高强混凝土截面高度等参数对该类梁承载力、刚度和变形的影响规律,对比分析了 GFRP筋异强混凝土简支梁与GFRP筋普通混凝土简支梁、GFRP筋高强混凝土简支梁力学性能的差别。3.依据此类梁的力学性能特点,结合相关的FRP筋混凝土结构规范和变形协调关系推导出相对界限受压区高度与界限配筋率的计算方法,基于数值仿真分析结果建立GFRP筋异强混凝土简支梁正截面抗弯承载力计算公式,同时给出该类梁的相关设计建议。4.基于最小刚度原则,结合GFRP筋异强混凝土简支梁的特点,推导出GFRP筋异强混凝土梁的挠度计算公式。
[Abstract]:With the development of high-strength concrete, high-strength concrete has been gradually used in civil engineering structures.High strength concrete has some defects in crack resistance and ductility because of its poor deformability and easy cracking, which limits the application of high strength concrete.The material waste will be caused by the failure to make full use of the compressive performance of the high strength concrete in the tensile zone.If the high strength concrete is used only in the key parts of the engineering structural members and the ordinary concrete is still used in other parts, the advantages of high strength concrete with high compressive strength and good economy of ordinary concrete can be fully utilized to realize the organic combination of the two.Based on this, the flexural members with high strength concrete in compression zone, ordinary concrete in tension zone and GFRP bar in tensile reinforcement are constructed, which can make full use of the characteristics of high strength concrete compressive strength in compression zone.It can also give play to the good characteristics such as light weight, high strength and corrosion resistance of GFRP bars in tensile zone, and can avoid the waste of materials caused by the use of high strength concrete in full section.On the basis of experimental verification, the numerical analysis of mechanical properties of this kind of simply supported beam is carried out, and the influence of different parameters on the flexural bearing capacity and stiffness of this kind of beam is obtained, and the formula for calculating the flexural bearing capacity and stiffness of normal section of this kind of beam is established.Finally, the related design suggestions of this kind of beams are given, which provide technical support for relevant technical specifications and practical engineering applications.In view of the lack of research on this kind of components at home and abroad, this paper carries out the following four aspects of work: 1.Based on ABAQUS software, the finite element models of 10 reinforced gradient concrete simply supported beams and FRP reinforced concrete simply supported beams are established. The load-displacement curves of 10 specimens under vertical static action are obtained, and compared with the existing experimental data.The rationality of the modeling method in this paper is verified, and the modeling method for this kind of beam is put forward. 2. 2.The numerical simulation analysis of the propagation parameters of 28 simple supported beams with different strength concrete under vertical static load is carried out to explore the strength grade of concrete in the compression zone of simple supported beams with different strength concrete and the reinforcement ratio of GFRP bars in the tensile zone.The influence of section height of high strength concrete on the bearing capacity, stiffness and deformation of this kind of beams is studied. The difference of mechanical properties between GFRP reinforced concrete simple supported beams and GFRP reinforced ordinary concrete simple supported beams is compared and analyzed.According to the characteristics of mechanical properties of this kind of beams, the calculation method of the height of the relative limit compression zone and the limit reinforcement ratio is deduced according to the relevant specifications and deformation coordination relations of concrete structures with FRP bars.Based on the results of numerical simulation, a formula for calculating the flexural bearing capacity of normal section of GFRP reinforced concrete simple supported beams is established, and the relevant design suggestions of this kind of beams are given.Based on the principle of minimum stiffness and the characteristics of GFRP reinforced concrete simply supported beams, the deflection calculation formula of GFRP reinforced concrete beams is derived.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU37

【参考文献】