MONOTONIC AND CYCLIC BEHAVIORS OF ENERGY-DISSIPATING THREADED MECHANICAL SPLICES

摘要

In this study, energy-dissipating threaded mechanical splices are developed. The spice is composed of a hollow steel coupler threaded throughout its length and two reinforcing bars with threads at their ends. The coupler is designed to fail with sufficient energy dissipation. The amount of energy dissipation at the coupler is controlled by the coupler thickness and the gap length which are invested in this study by a series of monotonic and cyclic loading tests. The couplers are made from SS400 steel and the threaded bars are 20-mm-diameter steel bars with the nominal yield strength of 500 MPa. The coupler thickness and the coupler gap length are varied. In compression, the mechanical splices exhibit higher compressive strength with more post-buckling resistance than the plain control bar by about 12%. In addition, the energy dissipation of the splice is 5 times the plain bar. In tension, the maximum load is close to the capacity of the coupler as intended. The energy dissipation of the mechanical splices increases when the coupler gap length increases. However, the ductility of plain bars is approximately 5 times the ductility of the splices in tension. The spices with different gap lengths are subjected to cyclic loading. It is important to note that the deformation in tension is limited by the tension rupture of a coupler. For a column with failure controlled by buckling of reinforcing bars, the energy dissipating threaded mechanical splice can improve the post-yielding behavior with less difficulty in repair.