PSI - Issue 78

Maria Maglio et al. / Procedia Structural Integrity 78 (2026) 153–160

160

Conclusions This study assessed the performance of Scissor-Toggle Brace Damper (STBD) systems through a comparative analysis of three configurations, using amplification factor – displacement diagrams derived from nonlinear pushover analyses. The investigation considered the influence of member deformability and geometric nonlinearities (P – Delta effects) under four distinct modeling conditions. Configuration 1, based on a traditional layout from the literature, showed limited effectiveness. Due to the connection of the knee-brace to the beam (rather than the beam – column joint) and the impact of element deformability, the dissipative device did not activate within the analyzed displacement range, resulting in negligible amplification. Configuration 2, which modifies the connection detail by anchoring the system directly to the beam – column joint while preserving a 9° internal angle, demonstrated the best performance. This setup achieved the highest amplification factor ( =5.47 ) and successfully activated the dissipative device. Although some discrepancies were observed between theoretical and numerical amplification values, particularly due to deformability and geometric nonlinearities, the results confirmed the system's capacity to significantly amplify displacement at relatively low structural deformations. Configuration 3 introduced a larger internal angle to increase device clearance and accommodate compressive displacements. While this adjustment offered practical advantages in terms of space and constructability, it led to a reduction in the amplification factor ( =3.23 ), making it less effective than Configuration 2 from a performance standpoint. Overall, the results highlight that the STBD system’s efficiency is highly sensitive to geometric parameters and support conditions. Amplification performance is notably reduced by member deformability and non-ideal connection layouts. Therefore, achieving optimal damping efficiency requires careful design-particularly with regard to device placement, internal geometry, and consideration of nonlinear effects. Further research should investigate additional geometric arrangements and extend the study to dynamic time-history analyses for a more comprehensive evaluation. References Piluso, V., Di Benedetto, S., Francavilla, A.B., Latour, M., Maglio, M., Montuori, R., Nastri, E., Rizzano, G., 2022. FREEDAM connections: Conception, testing and behaviour under seismic actions. Ingegneria Sismica 39(2). Maglio, M., Montuori, R., Nastri, E., Piluso, V., 2022. Design, analysis and assessment of MRFs equipped with FREEDAM connections and designed by TPMC: Comparison with traditional connections. Lecture Notes in Civil Engineering 262, 508 – 516. Maglio, M., Montuori, R., Nastri, E., Piluso, V., Pisapia, A., 2024. Probabilistic design procedure for steel moment resisting frames equipped with FREEDAM connections. Structural Safety 109, 102465. Maglio, M., Naddei, C., Nastri, E., Russo, R., Todisco, P., 2021. Design and analysis of FREEDAM frames: Comparison with traditional connections. COMPDYN Proceedings. Swain, S.S., Patro, S., S., Sinha, R., 2016. Numerical methodology for dynamic analysis of buildings with friction dampers. Bulletin of the New Zealand Society for Earthquake Engineering, 49(3), 245-266. Zhang, Z., Zhang, J., Fang, C., Zhang, Y., Li, Y., 2023. Emerging steel frames with Fe-SMA U-shaped dampers for enhancing seismic resilience. Journal of Infrastructure Preservation and Resilience 4, 6. Hanson, R.D., Soong, T.T., 2001. Seismic Design with Supplemental Energy Dissipation Devices, in Volume 8 di Engineering monographs on miscellaneous earthquake engineering topics, pp. 135. Constantinou, M.C., Tsopelas, P., Hammel, W., Sigaher, A.N., 2001. Toggle-Brace-Damper Seismic Energy Dissipation Systems. Journal of Structural Engineering 127(2). Huang, C., McNamara, R., 2006. The Efficiency of the Motion Amplification Device with Viscous Damper, 8th National Conference for Earthquake Engineering, Paper No. 62, San Francisco, CA. Hwang, J., Huang, Y. and Hung, Y., 2005. Analytical and experimental study of toggle-brace-damper systems. Journal of Structural Engineering 131(7), 1035-1043. Shao, S., Miyamoto, H., 2002. Seismic Performance Improvement of a Torsional Irregular Concrete Shear Wall Building Using Toggle-Brace Dampers. Sigaher, A.N., Constantinou, M.C., 2003. Scissor-jack-damper energy dissipation system. Earthquake Spectra 19(1), 133 – 158. Computers and Structures Inc., 2000. SAP2000: Static and Dynamic Finite Element Analysis of Structures. Computers and Structures Inc., Berkeley, CA.