GluBam植筋抗拔性能试验研究

发布时间：2018-06-17 22:14

本文选题：植筋 + 胶合竹　；参考：《湖南大学》2015年硕士论文

【摘要】：随着现代竹结构的发展,结构对节点性能的要求越来越高,对于某些重型竹结构建筑,采用传统的节点连接方式难以满足结构对刚度和承载力的要求。植筋连接作为一种新型连接方式,具有承载力高、刚度大和耐久性好等优点,对于推进现代竹结构的发展有重要意义,然而,目前国内外对胶合竹植筋连接的研究还很少。本文选取截面尺寸a、螺杆直径dr、长细比λ和胶层厚度t为试验参数,设计了两组试验,分别对GluBam植筋连接的力学性能和锚固机理展开研究,为GluBa m的植筋连接设计提供基础性数据。本文开展的主要工作及取得的成果如下:首先,通过对96根GluBam植筋试件进行对拉试验,探讨了各参数对Glu Bam植筋连接性能的影响,并得到了3种典型破坏模式,分别为Glu Bam的分层开裂破坏、螺杆从GluBam中被拔出和螺杆屈服。研究结果表明,当截面尺寸a较小时,试件容易发生Glu Bam的分层开裂破坏;长细比λ对植筋连接的力学性能和破坏模式有显著影响,并且存在一个临界长细比λcr,当长细比λ达到临界长细比λcr时,试件发生螺杆屈服破坏,破坏前试件有明显的变形,属于延性破坏,当螺杆直径dr为12mm时,λcr为12.5,当dr为16mm和20mm时,λc r为15;此外,螺杆的直径和胶层厚度对试件的破坏形态也有一定的影响。其次,通过对32根螺杆内贴片的GluBam植筋试件进行对拉试验,揭示了各参数对Glu Bam植筋连接剪应力分布规律的影响,试验结果表明,各参数对界面上黏结应力的峰值及其位置等均有影响。基于线弹性假设,本文提出了植筋锚固力计算模型,并与试验数据进行了对比分析,对比结果表明,线弹性分析模型与试验结果吻合较好。最后,基于试验结果,本文拟合得到了Glu Bam植筋连接的锚固抗拔力计算公式,给出了具有一定可靠度的长细比数值解。结合木结构植筋的研究成果以及本文的研究结果,给出了Glu Bam植筋连接参数的设计建议取值:GluBam的截面边长a应为螺杆直径dr的7倍,螺杆直径不宜超过M20,锚固长细比λ应大于植筋的临界长细比λcr但不应超过极限长细比λu,胶层的厚度宜取2mm,此外,在植筋设计过程中还应考虑施工质量对植筋性能的影响。
[Abstract]:With the development of modern bamboo structures, the performance of joints is becoming more and more important. For some heavy-duty bamboo structures, it is difficult to meet the requirements of stiffness and bearing capacity by using the traditional connection method. As a new type of connection, it has the advantages of high bearing capacity, high stiffness and good durability. It is of great significance to promote the development of modern bamboo structure. However, there are few researches on glued bamboo planting connections at home and abroad. In this paper, the cross section size a, screw diameter drr, aspect ratio 位 and rubber thickness t are selected as test parameters, and two groups of tests are designed to study the mechanical properties and anchoring mechanism of GluBam tendons. It provides the basic data for the design of GluBa m. The main work and results obtained in this paper are as follows: firstly, through tensile tests on 96 GluBam tendons, the effects of various parameters on the connection properties of Glu Bam tendons are discussed, and three typical failure modes are obtained. The delamination cracking of Glu Bam, the pull-out of the screw from GluBam and the yield of the screw, respectively. The results show that the delamination cracking of Glu Bam is easy to occur when the section size a is small, and the aspect ratio 位 has a significant effect on the mechanical properties and failure mode of the connection. And there exists a critical slenderness ratio 位 cr.When the slenderness ratio 位 reaches the critical aspect ratio 位 cr, the screw yield failure occurs in the specimen, and the specimen has obvious deformation before failure, which belongs to ductile failure. When the diameter of screw is 12mm, 位 cr is 12.5, and when dr is 16mm and 20mm, 位 c r is 15. In addition, the diameter of screw and the thickness of adhesive layer also have some influence on the failure mode of the specimen. Secondly, the effects of various parameters on the shear stress distribution of Glu Bam connections are revealed by the tensile test of 32 GluBam tendons attached to the screws. The experimental results show that the shear stress distribution of Glu Bam connections is affected by the experimental results. Each parameter has an effect on the peak value and position of bond stress at the interface. Based on the assumption of linear elasticity, this paper puts forward a calculation model of anchor force of steel bars, and compares it with the experimental data. The comparison results show that the linear elastic analysis model is in good agreement with the experimental results. Finally, based on the experimental results, the formula of Anchorage pull-out force of Glu Bam connections is obtained, and the numerical solution of slenderness ratio with certain reliability is given. Combined with the research results of the wood structure and the research results of this paper, the design of the connecting parameters of Glu Bam tendons is given. It is suggested that the cross section side length a of 1: GluBam should be 7 times of the diameter of the screw rod. The screw diameter should not exceed M20, the Anchorage aspect ratio 位 should be greater than the critical aspect ratio 位 cr but not exceed the limit aspect ratio 位 u, and the thickness of rubber layer should be 2 mm. In addition, the effect of construction quality on the performance of planting reinforcement should be considered in the process of design.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU366.3

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