Experimental and numerical investigation of steel energy-dissipating #br#
hinge under cyclic loading
Zheng Lianqiong1,2 Yan Guiyun1,2 Wei Changgui1 Ma Yongchao1,2
1. School of Civil Engineering, Fujian University of Technology, Fuzhou 350118, China；2. Fujian Provincial Key
Laboratory of Advanced Technology and Informatization in Civil Engineering, Fujian University of Technology, Fuzhou 350118, China
Abstract：A new type of steel energy-dissipating hinge, which can be used to connect a prefabricated reinforced concrete beam and column in a frame structure in high seismic regions, is proposed in this study. Based on the seismic design concept commonly referred to as “strong connection”, this steel hinge works by forcing the plastic hinge outward from the column face. The hysteretic tests for two steel energy-dissipating hinges were conducted. The experimental results demonstrate that the specimens have good bearing performance and can rotate around the pin axis. The failures of the specimens were concentrated on the flange, primarily due to the buckling of the compressed flange, or due to fractures forming on the tensioned flange. The hysteretic curves of the energydissipating hinge appeared to be plump, and the energy dissipation coefficient could be above 3.0, exhibiting good energy absorption capacity and ductility of the steel hinges without significant strength or stiffness degradation observed. The plastic rotation of the energy-dissipating hinge was 0.055 rad, and the ductility factors of the two specimens were greater than 4.0, conforming to the code requirements. Furthermore, a finite element (FE) model was established for the energy-dissipating hinge specimen, and the FE results agreed well with the test results. By using the FE model, the mechanism was studied and parametric analysis was conducted for the steel energy-dissipating hinge. It was found that when the energy dissipation reaches the peak load, the center of the energy dissipation element can reach the full-section plasticity, meeting the rotation capability required by the plastic design. It was also found that the bearing capacity did not decrease during the rotation process. The initial stiffness, bearing capacity, and rotation capacity of the energy-dissipating hinge were significantly affected by the weakening degree and length of the energy-dissipating hinge. The weakening range of energy-dissipatinghinge, however, had slight effect on the hysteretic curve. Based on the parametric analysis, a simplified hysteretic model and some design principles were proposed for this energy-dissipating hinge. The predictions based on the simplified hysteretic model agreed well with the experimental and FE results.
