Seismic resilience of steel plate shear walls enhanced with innovative hybrid viscoelastic dampers: A numerical investigation

Abstract

ntroduction and Research Rationale Steel Plate Shear Walls (SPSWs) are recognized as efficient lateral load-resisting systems. However, their conventional design is often constrained by significant drawbacks, including pronounced stress concentrations in the web plate and boundary elements. These concentrations lead to undesirable buckling, strength degradation under cyclic loads, and complex, costly repairs following seismic events. This research addresses these limitations by proposing and numerically investigating a novel hybrid structural system that integrates a Multi-Layer Viscoelastic Damper (MLVED) within a conventional SPSW framework. The study aims to develop a damage-control strategy that shifts inelastic demand towards replaceable dampers, thereby enhancing seismic resilience and repairability. A particular focus is placed on characterizing the system's unique performance signature—its capacity for high energy dissipation and force reduction—and understanding the consequential trade-offs, such as inter-story drift behavior, within a performance-based design context. Research Methodology A systematic three-phase numerical methodology was employed, utilizing the finite element analysis software ABAQUS/Standard to progressively investigate the proposed system from component validation to full-scale seismic assessment. Phase I: Validation and Baseline Performance Comparison High-fidelity finite element models were developed, commencing with the validation of a conventional SPSW and the Multi-Layer Viscoelastic Damper (MLVED) against established experimental benchmarks. Subsequently, a hybrid SPSW-MLVED model was assembled and subjected to nonlinear static (pushover) and quasi-static cyclic analysis. This phase provided the foundational comparison, quantifying the hybrid system's improvements in ultimate strength, hysteretic energy dissipation, self-centering tendency, and its efficacy in shifting damage away from primary components toward the damper as a sacrificial fuse. Phase II: Parametric Study for Damper Optimization Following the baseline comparison, a dedicated parametric study was conducted to isolate the influence of individual MLVED design parameters. The properties varied included the viscoelastic shear modulus (C₁₀), loss factor (D), damper length (L), number of rubber layers (N), and layer thickness (T). Analyzing the resulting pushover and hysteresis responses identified clear governing trends: parameters C₁₀, L, and N predominantly controlled system strength and stiffness, while the loss factor D exclusively governed energy dissipation capacity. The outcomes of this phase directly informed the selection of an optimized damper configuration for advanced system-level analysis. Phase III: System-Level Seismic Validation The optimized hybrid configuration was implemented within a multi-story building model and evaluated under realistic dynamic loading. Nonlinear time history analysis was performed using the recorded ground motion from the 1999 Kocaeli earthquake. This final phase assessed the global seismic performance, quantifying key metrics such as fundamental period, inter-story drift profiles, total base shear, and the breakdown of energy dissipation between the structural frame and the dampers, thereby validating the system's performance under transient seismic demands. Key Findings and Results The integrated numerical investigation yielded comprehensive insights into the performance of the hybrid SPSW-MLVED system: I. Fundamental Behavioral Transformation: The integration of the MLVED fundamentally altered the system's response, transitioning it from a traditional, plate-yielding mechanism to a damage-controlled one. This was evidenced by a drastic reduction (exceeding 60%) in plastic strain within the primary steel components. II. Decoupled Design Parameters: The parametric study established a clear hierarchy of influence. The damper's shear modulus (C₁₀), length (L), and number of layers (N) were identified as the primary governors of system strength and stiffness. In contrast, the loss factor (D) was proven to be the principal parameter controlling hysteretic energy dissipation, enabling targeted design. III. Enhanced Component-Level Performance: Under cyclic loading, the hybrid system demonstrated a 22% higher ultimate load capacity and generated fuller, more stable hysteresis loops, providing approximately 35% greater energy dissipation per cycle alongside a strong self-centering tendency that minimized residual displacements. IV. Validated System-Level Seismic Response: When subjected to real ground motions, the hybrid system in a multi story configuration confirmed its core damage control function. It achieved a significant reduction in peak base shear (~23%) and successfully redirected 20.0 % of the total seismic input energy to be dissipated by the MLVEDs, which acted as effective structural fuses. This supplemental dissipation reduced the plastic energy share in the primary structure by approximately 15 %, directly demonstrating the system's capacity to protect key structural elements. V. Characteristic Performance Trade-off: The analysis quantified a key behavioral signature: the system's inherent period elongation and high damping capacity, which underpin its force reduction and energy dissipation benefits, concurrently resulted in increased inter-story drift compared to the stiffer conventional SPSW. This highlights the necessity of a performance-based design framework for its application. Conclusion and Contribution This research conclusively establishes the SPSW-MLVED hybrid system as a viable and innovative pathway for advancing seismic resilience in steel structures. By systematically addressing the limitations of conventional SPSWs, the study provides a validated numerical framework for a design strategy that prioritizes damage control and repairability. The system's demonstrated ability to reduce force demands, dissipate energy efficiently through replaceable components, and promote self-centering offers a compelling alternative for performance-based engineering. The findings contribute significantly to the field by: (1) clarifying the distinct roles of key damper parameters, providing a roadmap for tailored design; (2) offering quantitative evidence of the system's efficacy at both component and system levels; and (3) defining its suitable applications within a performance-based context, thereby laying a foundation for future development of design guidelines and experimental validation. This work shifts the paradigm from mere strength enhancement to intelligent damage management for modern seismic-resistant systems.