Bridge Torsional Flutter: Critical Wind Speed Lab (2D)

This 2D companion drives the same coupled torsional-flutter ODE as the 3D Tacoma Narrows lab through a plain canvas view built for reading the mechanism rather than orbiting a scene: wind speed, torsional stiffness and structural damping are all live sliders, a phase portrait of θ against θ′ shows the oscillator spiraling in (stable) or out (flutter) in real time, and a semilog amplitude trace turns the exponential growth or decay predicted by the math into a straight line you can watch form. A live "critical wind speed" readout recomputes Vcr from the current stiffness and damping every frame, so you can see exactly how a stiffer deck or more mechanical damping pushes the flutter threshold higher — the real engineering lever behind the 1950 Tacoma Narrows redesign.