轴心受力纤维增强复合材料压杆的性能研究

发布时间：2018-05-30 08:35

本文选题：GFRP + CFRP　；参考：《南京理工大学》2017年硕士论文

【摘要】：本文依托高性能纤维增强复合材料-索穹顶结构体系的研究课题,以索穹顶中的纤维增强复合材料压杆为研究对象,对简单支承条件下拉挤成型的GFRP和CFRP杆分别进行了轴压受力性能试验和有限元数值分析。FRP压杆的端部是容易破坏的薄弱环节,端部加强会对其极限承载力和破坏模式产生很大的影响。本文通过对比四种不同加强端加强的GFRP短杆试验结果,提出了经济有效的聚酯纤维布浸胶加强方法,为后续长杆的稳定性试验奠定了基础。针对FRP构件不可避免的几何缺陷,论文结合试验结果,采用ABAQUS软件分析得到了两种杆的初始缺陷计算方法。通过对比两种压杆试验的有限元模型分析结果和试验结果,验证了引入初始缺陷并结合二维Hashin准则进行有限元数值分析的有效性。通过有限元分析得到两种压杆可能会发生强度、非弹性失稳和弹性失稳破坏模式之一;简单支承条件下的GFRP压杆,径厚比相同时,极限承载力随长细比的增大而减少,且长细比较小时下降快,长细比较大时下降缓慢。长细比相同时,径厚比越大,极限承载力越高,随着长细比的增大,径厚比对极限承载力的影响会变弱;相同管径的CFRP压杆,构件极限应力在长细比较小时下降较快,在长细比较大下降相对平缓,长细比相同管径不同时,极限应力相差不大。在一定的纤维含量内,拉挤成型CFRP杆稳定承载力与纤维的体积含量基本呈线性增长的关系。通过ABAQUS数值计算得到了文献修正后的欧拉公式近似求解拉挤成型CFRP长杆极限承载力的适用范围,并画出了简单支承条件下拉挤成型CFRP杆的抗压极限强度与λ的关系曲线。
[Abstract]:In this paper, based on the research topic of high performance fiber reinforced composite material cable dome structure system, the fiber reinforced composite compression rod in cable dome is taken as the research object. The axial compression behavior tests and finite element numerical analysis of the GFRP and CFRP rods formed by pull-down extrusion with simple support conditions were carried out respectively. The end part of the GFRP compression bar is a weak link which is easy to be destroyed. End reinforcement has great influence on ultimate bearing capacity and failure mode. By comparing the test results of four kinds of GFRP short bar strengthened with different strengthening ends, this paper presents an economical and effective strengthening method of polyester fiber cloth impregnated glue, which lays a foundation for the stability test of the following long rod. In view of the inevitable geometric defects of FRP members, two methods for calculating the initial defects of rods are obtained by ABAQUS software analysis combined with the experimental results. By comparing the results of finite element model analysis and experimental results of two kinds of compression bar tests, the validity of finite element numerical analysis by introducing initial defects and combining with two-dimensional Hashin criterion is verified. Through finite element analysis, it is found that one of the failure modes of strength, inelastic instability and elastic instability may occur in two kinds of compression rods, and the ultimate bearing capacity of GFRP compression bar decreases with the increase of aspect ratio when the ratio of diameter to thickness is the same under the condition of simple support. And the length of the smaller than the drop faster, the longer the larger the decline is slow. At the same aspect ratio, the higher the ratio of diameter to thickness, the higher the ultimate bearing capacity. With the increase of aspect ratio, the influence of the ratio of diameter to thickness on ultimate bearing capacity becomes weaker, and the ultimate stress of CFRP compression rod with the same diameter decreases more quickly when the ratio of length to diameter increases. When the ratio of length to fineness decreases relatively slowly, and the ratio of length to diameter is different, the ultimate stress is not different. In a certain fiber content, the stable bearing capacity of pultrusion forming CFRP rod is linearly increased with the volume content of fiber. Through the ABAQUS numerical calculation, the suitable range of the ultimate bearing capacity of the long CFRP rod formed by pullout is approximately solved by the modified Euler formula, and the relation curve between the ultimate compressive strength and 位 of the CFRP rod formed by pull-down extrusion with simple supporting conditions is drawn.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU399

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