EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS, cilt.45, sa.5, ss.779-796, 2016 (SCI-Expanded)
This paper reports on experimental studies carried out on a 200kN, 120mm-capacity prototype of the newly developed multidirectional torsional hysteretic damper for seismic protection of structures. The main goal of the experiments is to test the validity of the theory developed in a companion paper and to evaluate the low-cycle fatigue performance of the energy dissipaters of the damper. Because the design and configuration of the damper allow easy replacement of the energy dissipaters, four sets of energy dissipaters were produced out of S355J2+N, C45 (two sets), and 42CrMo4+QT steel grades. Force-displacement response of the multidirectional torsional hysteretic damper is studied through fully reversed cyclic quasi-static displacement-controlled tests that were carried out in compliance with EN 15129. Following the verification tests, with the aim of studying fatigue and fracture behavior of the cylindrical energy dissipaters of the device, certain numbers of them were subjected to further cyclic tests up to failure, and observations on their fatigue/fracture behavior are reported. The experimental verification test results proved the validity of the developed theory and component design assumptions presented in a companion paper. Furthermore, the energy dissipaters exhibited excellent torsional low-cycle fatigue performance with number of cycles to failure reaching 118 at a maximum shear strain of 8% for S355J2+N steel grade. Copyright (c) 2015 John Wiley & Sons, Ltd.