Study On Stiffness Of Anchor Plate For Post-installed Fastenings Under Axial Tension

While calculating the internal force of anchors of post-installed fastenings in concrete structure, the code used the following assumption: The junctional serface of fixture and base material still remain plane after force-deformation, and the anchor plate does not deform under the design actions, so the anchor plate shall be sufficiently stiff. Usually, there are two ways to increase the stiffness of anchor plate: setting stiffening rib and reduce cross-thickness ratio of anchor plate, while using post-installed fastenings in curtain wall engineering of civil engineering, setting stiffening rib to increase the stiffness of anchor plate is rarely used, the main way to improve the stiffness of anchor plate is reducing the cross-thickness ratio.The purpose of the paper is analyzing the influence of anchor plate stiffness to the adhesive anchor of post-installed fastenings tensile performance, and determining the scope of the anchor plate stiffness to satisfy the requirements of calculation assumes, then providing the basis for the value of anchor plate thickness of post-installed fastenings in concrete structure. In order to reach the purpose, two types of anchor arrangement and three kinds of thickness of anchor plate were designed in post-installed fastenings in concrete structure, and a static drawing test was carried out. Moreover, with the help of ANSYS software, ultimate limit capacity of specimens, Anchor strain distribution characteristics and the anchor plate deformation characteristics were simulated. The main contents are as follows:(1)Research situation of post-installed fastenings and rigid-plate connection were collated and summarized, the main affecting factors of post-installed fastenings was analyzed and summarized, and described the two factors of affecting the anchor plate’s stiffness and the method of increasing the stiffness.(2)The failure modes and the calculation method of bearing capacity of tensile adhesive anchors were summarized.(3)Tensile test device was designed and two group of specimens with four anchors were tested, then, the failure mode, ultimate load, anchor pulling displacement and strain, deformation and strain of the anchor plates of six specimens were readed.(4)The experimental data were systematically analyzed and summarized, the studies show that, in the testing process, the ductility of anchor group of post-installed fastenings improve with reducing cross-thickness ratio of the anchor plate, and strain distribution is more uniform on the anchor section. Based on the experimental results and analysis,the design suggestions of scope of anchor plate cross-thickness ratio in concrete post-installed fastenings structure under axial tension change are proposed.(5)With the help of ANSYS finite element software, anchor group of testing specimens was numerical simulated. The numerical simulation values of the failure characteristics of specimens, ultimate limit capacity of specimens and deformation characteristics of the anchor plates agree with the experimental results in a certain extent.Finally, summarization of the whole content is issued and advice on further research is presented.