Performance assessment
Calculating…
The result will update from the selected demand, capacity and threshold set.
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Target roof displacement
m
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Roof drift proxy
%
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Sa at performance point
g
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Sd at performance point
m
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Ductility demand μ
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Effective period T*
s
Capacity–demand diagram
ADRS format with all selected performance-state boundaries shown as drift-based displacement bands.
Elastic demandReduced demandCapacityPerformance pointBackground bands = threshold states
Pushover curve and performance states
Roof displacement thresholds are plotted directly on the capacity curve so every state remains visible.
PushoverEqual-energy bilinearTarget displacement
Demand spectrum
Elastic spectral acceleration and the effective-period demand.
Elastic demand Se(T)Effective-period demand
Ground-motion time history
Shown when a recorded acceleration time history is active.
Analysis summary
Key values used in the N2 screening calculation.
Method note — The MDOF pushover curve is transformed to an equivalent SDOF system and idealised by equal-energy matching. The N2 Rμ–μ–T relation is then used to estimate target displacement. Global roof drift is only a screening proxy; code acceptance checks are generally component- and system-specific.
References: Fajfar, P. (2000), "A Nonlinear Analysis Method for Performance Based Seismic Design", Earthquake Spectra 16(3); EN 1998-1:2004, Eurocode 8 Part 1; EN 1998-3:2005, Eurocode 8 Part 3, Annex A/B/C; ASCE/SEI 41-23, Seismic Evaluation and Retrofit of Existing Buildings; FEMA P-58 / Hazus 6.1 Technical Manual, drift-sensitive nonstructural fragility parameters.