This study develops a unified modelling and optimization framework for vertical seismic isolation (VSI) of reinforced-concrete (RC) buildings using four smart-damper families: magnetorheological (MR), magnetorheological elastomer (MRE), superelastic shape-memory alloy (SMA), and friction–viscous (FV) hybrids. The framework embeds device forces directly into the structural equations of motion using topology-specific connectivity operators (story-split, column-line, perimeter), which enables consistent comparisons across device types and layouts. Nonlinear multi-record time-history analyses are conducted for two RC archetypes (6- and 12-storey) under scaled vertical ground motions, and performance is assessed using roof vertical displacement and acceleration ratios alongside standard side-effect checks (IDR and base shear). Two device-agnostic indices are introduced to support fair ranking: the Device-Normalized Efficacy Index <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$(\text {DNEI}),$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <mtext>DNEI</mtext> <mo stretchy="false">)</mo> <mo>,</mo> </mrow> </math></EquationSource> </InlineEquation> which relates median roof-displacement reduction to peak device demand, and the Robustness Index <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$(\text {RI}),$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <mtext>RI</mtext> <mo stretchy="false">)</mo> <mo>,</mo> </mrow> </math></EquationSource> </InlineEquation> which reflects record-to-record dispersion. Results show modest but consistently repeatable median reductions in vertical roof displacement at the tested device budgets (about 3.3% for the 6-storey archetype and about 2.0% for the 12-storey archetype), with uniformly high robustness <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$(\text {RI}\approx 0.9993$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <mtext>RI</mtext> <mo>≈</mo> <mn>0.9993</mn> </mrow> </math></EquationSource> </InlineEquation>–0.9997) and very low device energy demand. MR devices provide the highest <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$\text {DNEI}$</EquationSource> <EquationSource Format="MATHML"><math> <mtext>DNEI</mtext> </math></EquationSource> </InlineEquation> at high command levels, whereas FV/MRE configurations tend to deliver the strongest robustness. Overall, the findings indicate that VSI can be achieved reliably at very low device utilisation for service-to-moderate vertical intensity; larger reductions likely require greater coverage, stronger tuning to the short-period vertical band, or objectives that place higher weight on efficacy.

Smart-damper vertical seismic isolation for RC buildings: unified equations, constitutive models, and robust multi-record optimization

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发表日期：

2025年12月29日

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Neha H. Rajput,
Naresh K. Solanki

摘要

This study develops a unified modelling and optimization framework for vertical seismic isolation (VSI) of reinforced-concrete (RC) buildings using four smart-damper families: magnetorheological (MR), magnetorheological elastomer (MRE), superelastic shape-memory alloy (SMA), and friction–viscous (FV) hybrids. The framework embeds device forces directly into the structural equations of motion using topology-specific connectivity operators (story-split, column-line, perimeter), which enables consistent comparisons across device types and layouts. Nonlinear multi-record time-history analyses are conducted for two RC archetypes (6- and 12-storey) under scaled vertical ground motions, and performance is assessed using roof vertical displacement and acceleration ratios alongside standard side-effect checks (IDR and base shear). Two device-agnostic indices are introduced to support fair ranking: the Device-Normalized Efficacy Index $(\text {DNEI}),$ $(DNEI),$ which relates median roof-displacement reduction to peak device demand, and the Robustness Index $(\text {RI}),$ $(RI),$ which reflects record-to-record dispersion. Results show modest but consistently repeatable median reductions in vertical roof displacement at the tested device budgets (about 3.3% for the 6-storey archetype and about 2.0% for the 12-storey archetype), with uniformly high robustness $(\text {RI}\approx 0.9993$ $(RI \approx 0.9993$ –0.9997) and very low device energy demand. MR devices provide the highest $\text {DNEI}$ $DNEI$ at high command levels, whereas FV/MRE configurations tend to deliver the strongest robustness. Overall, the findings indicate that VSI can be achieved reliably at very low device utilisation for service-to-moderate vertical intensity; larger reductions likely require greater coverage, stronger tuning to the short-period vertical band, or objectives that place higher weight on efficacy.