Energy Dissipation in Frame Structures using Sliding Lever Mechanism Technique

Aim: The aim of this study was to investigate the seismic energy dissipation mechanism of a novel and newly proposed sliding lever damping energy dissipation through dynamic shake table testing. Background: Typical energy dissipation systems consist of brace members and installed dampers, which are directly connected to structural members such as beams, columns and joint regions. This can cause additional load concentrations and may require retrofitting or strengthening of existing structures. In order to avoid the load demand on the main structural system, a new energy dissipation technique based on a sliding lever mechanism is proposed and tested through dynamic testing. Objective: The objective of this study was to test a new sliding lever damping energy dissipation through dynamic shake table testing within the scope of steel frame structures. Methods: In order to investigate the proposed energy dissipation configuration, a 1/3rd reduced scaled, three-story and one bay steel frame model has been fabricated and tested in a uni-directional shaking with increasing excitation and, without and with the new technique. For the sliding lever energy dissipation configuration, a non-structural frame (i.e., carrying no gravity loads) has been constructed and provided with an installed ramp-damper assembly. The shaking responses in the form of acceleration and displacement histories have been obtained during the experimental program and compared in order to check the efficiency of the proposed configuration. Results: The results showed a reduction of 55% to 6% in stories deflections and 36% to 12% in acceleration with the newly proposed sliding lever mechanism energy dissipation technique. The top story peak displacements for the damped frame case decreased by 36.55% in case of 0.1 g, 37.95% in case of 0.2g, 31.89% in case of 0.3g, 38.05% in case of 0.4g, 29.37% in case of 0.5g and 12.06% in case of 0.6g shaking excitation. Conclusion: It has been confirmed from the current experimental studies that the new configuration was quite effective in reducing the overall displacement and acceleration response. The reduction in the structural response parameters was very significant during low excitation shaking, whereas, with the increase in shaking intensities, the responses varied with much less difference.