PSI - Issue 78

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

159

4.2. Configuration 2 To overcome the limitations identified in Configuration 1, the scissor-toggle bracing system was connected directly to the beam – column joint, while maintaining the internal angle θ at 9 ° . This adjustment reduces the angle Ψ , resulting in an increased amplification factor, which rises to =5.47 . The pushover analyses were conducted under the same four modeling conditions. The structure exhibits plastic behaviour starting from a force level of = 565.83 . Without accounting for large displacement effects, the responses of the deformable and rigid models are closely aligned, differing primarily in the initial elastic stiffness. When large displacement (P – Delta) effects are considered, notable differences arise in the plastic branches for the right (dx) and left (sx) loading directions: one curve shows a descending branch, while the other an ascending trend. For small top displacements, the relative displacement in the dissipative element substantially exceeds the inter-storey displacement , resulting in a high amplification factor. Consistent with previous configurations, the amplification factor observed during the analyzed displacement range remains below the theoretical value predicted by the analytical formula. However, this discrepancy is not critical, given that the amplification factor already attains significantly high values at a modest top displacement of 0.006 m.

Fig. 5. Amplification factor – displacement diagram for C2 configuration

4.3. Configuration 3 The third configuration builds upon Configuration 2 by increasing the internal angle θ resulting in an amplification factor =3.23 . This modification offers practical advantages by providing greater clearance for the dissipative element, reducing the likelihood of displacement constraints, especially when the device is subjected to compressive forces. However, this geometric adjustment results in a decrease in the amplification factor compared to the previous case. Based on the analyses, Configuration 2 remains the most effective solution among those considered for optimizing the performance of the scissor-toggle damper system.

Fig. 6. Amplification factor – displacement diagram for C3 configuration