CREATE_Bridge_SnapTest – Documentation
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OVERVIEW
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This directory contains experimental and numerical results for the
Bridge Snap Test under two different support conditions:

SS  -> Short Spring (higher stiffness)
LS  -> Long Spring  (lower stiffness)

The only difference between SS and LS cases is the spring length,
which modifies the global stiffness of the system:

    k = EA / L

Shorter spring  -> smaller L -> higher stiffness
Longer spring   -> larger L  -> lower stiffness

All other geometric and mass properties remain identical.


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NAMING CONVENTION
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Experimental file naming format:

    ExperimentalH2XXSS.txt
    ExperimentalH2XXLS.txt

Where:

H2XX  -> Water level identifier
SS/LS -> Spring support condition


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WATER LEVEL DEFINITION (H2XX)
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The label H2XX corresponds to the water depth relative
to the bridge deck height.

Water depth is defined as:

    h_water / h_deck =

    0.25
    0.50
    0.75
    1.00
    1.50

Meaning:

H222 -> 0.25 × deck height
H229 -> 0.50 × deck height
H236 -> 0.75 × deck height
H243 -> 1.00 × deck height
H257 -> 1.50 × deck height

These represent increasing submergence levels of the bridge deck:

0.25 -> Partial submergence
1.00 -> Water reaches deck height
1.50 -> Fully submerged deck


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EXPERIMENTAL DATA FORMAT
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Each experimental TXT file contains:

Column 1 -> Time [s]
Column 2 -> Displacement [m]

These represent free-decay snap tests under hydrodynamic loading.


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PHYSICAL INTERPRETATION
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For each water level and spring condition:

1. The bridge deck is displaced and released.
2. The structure undergoes damped oscillation.
3. Hydrodynamic effects influence:
   - Added mass
   - Linear fluid damping
   - Quadratic drag

Added mass is estimated from the measured mean period:

    m_a = (T^2 * (1 - zeta^2) * K) / (4*pi^2) - m

Where:
    T     = measured oscillation period
    K     = system stiffness
    m     = structural mass
    zeta  = damping ratio


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FOLDER STRUCTURE
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DataFiles/
    - Experimental displacement time histories
    - Numerical calibrated responses
    - Load-displacement stiffness data

Figures/
    - Experimental vs Numerical comparisons
    - Envelope plots
    - Decay comparisons
    - Calibration result plots

Scripts/
    - MATLAB calibration scripts
    - Runge-Kutta solver implementation
    - Optimization routines (GlobalSearch + fmincon)


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KEY VARIABLES
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Spring length      -> Controls stiffness (SS vs LS)
Water height ratio -> Controls hydrodynamic loading
Added mass         -> Computed from measured period
Drag coefficient   -> Optimized
Fluid damping      -> Optimized