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SFSI Project Update Shaking-Table Analyses. Tyler Ranf and Marc Eberhard University of Washington Austin, Texas Aug. 1-2, 2005. Scaling. Prototype. Structure Idealization. SFSI. Analysis Matrix. Shaking-Table Analyses. Data Available ( what can be simulated? )
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SFSI Project UpdateShaking-Table Analyses Tyler Ranf and Marc Eberhard University of Washington Austin, Texas Aug. 1-2, 2005
Scaling Prototype Structure Idealization SFSI Analysis Matrix
Shaking-Table Analyses • Data Available (what can be simulated?) • Linearity of Response (model complexity) • In-Plane Stiffness of Slab (modeling of slab) • Consistency of Measurements of Local Response (scope of optimization) • Modal Characteristics (model optimization / comparison with centrifuge) • Results of Simulations (preliminary)
First Yield (0.4-0.5%) Linearity of Response - Measured Peak Bent Drift Ratios
Rotation Translation In-Plane Slab Rigidity Deflected Shape Orthonormal Basis Vectors Symmetric Bending SS Bending Asymmetric Bending
In-Plane Slab Rigidity - Vector Decomposition Low-Amplitude Tests
Consistency of Data – Longitudinal Strain Envelopes East Column vs. West Column Averages
Consistency of Data – Average Curvature Envelopes East Column vs. West Column Averages
Identification of Modal Properties – Mode 1 Period Mode 1 Analysis Method Comparison – White Noise Excitation
Identification of Modal Properties – Mode 1 Period Mode 1 Excitation Comparison – Parameter Optimization Algorithm
Simulation - Maximum Displacement of Center of Mass 1D Sd and 3D FE Center of Mass Estimations
Simulation - Maximum Twist (Planar Rotation) 3D FE Twisting Estimations
Simulation - Displacement Histories at Low Amplitude Test 12
Simulation - Displacement Histories at High Amplitude Test 18
Conclusions • Negligible damage until run 13 (linear models OK). • Slab can be modeled as rigid or as a beam. • Strain-gauge and average curvature measurements consistent. • White noise, square wave and low-amplitude earthquake frequencies are nearly identical when input motions are considered. • Can accurately simulate maximum displacement at center of mass and maximum twist. • Displacement history can be approximated well for 3D FE (OpenSEES) model at both small and large bent drift amplitudes. Need to account for history.
Future Work • Calibration of OpenSEES model • Model optimization (objective function) • Detailed response • System Identification • Damping ratios • Nonlinear response • Quantify Effects of Motion Incoherency • Effects of Scale (with Purdue) • Effects of SFSI (with geotechs)
In-Plane Slab Rigidity - Vector Decomposition High-Amplitude Tests
Identification of Modal Properties - Periods Modes 1-3 using Eigensystem Realization Algorithm
Simulation - Displacement Histories at Moderate Amplitude Test 15