Interactive explainers for the failure modes a static diagram cannot show. One HTML file each. No libraries, no build step, no network requests.
A plated bolt passes every external inspection right up to the moment it fails. Pull the joint apart and watch the hydrogen gather at the first engaged thread — while the outside shows nothing at all.
The bolt holds the joint together, so it must be the bolt that carries the load. It is not: the members are far stiffer and absorb most of it by un-squeezing. Tighten it yourself and watch how much the bolt actually feels — and where that stops improving.
Shut a valve on a moving column of water and the pressure spike that follows is set by how fast you shut it — not by how hard the pump was pushing. Close it yourself, fast or slow, and watch the wave run the pipe.
One pump, one pipe, one duty — and the only thing you change is how hot the liquid is. The pressure arriving at the pump barely moves. What moves is the pressure at which the liquid boils, and it climbs until it reaches the pump.
Pressure and vacuum look like the same load with the sign changed. They are not the same problem: one is resisted by strength, the other by stiffness. Change the wall thickness and watch how far apart the two answers stay.
Warm a lithium cell's surroundings degree by degree. For a long way it just sits there, a little above ambient, looking like a healthy cell — and then one degree removes the temperature it was settling at, and there is nothing left to settle at.
Two metals in seawater. Change nothing but the proportions — not the alloys, not the water — and the same couple goes from outlasting the structure to perforating in three weeks.
An inspection programme is a bet that the crack sits in the findable band long enough for somebody to walk past it. Count the inspections that land in the band — raise the stress range far enough and the answer is none.
Three grades of steel in the same section, and three different capacities — until the strut gets slender enough that the three answers become one number, and the dearest steel buys nothing at all.
Hold steel at both ends and warm it, and the stress does not depend on how long it is — six metres and a hundred and twenty reach the same number. Allow a few millimetres of movement and suddenly length is the only thing that matters.
A round hole triples the stress beside it — at any size, pinhole or doorway. Flatten the same hole into a slit and the multiplier runs away, while the material you removed accounts for almost none of it.
Ten degrees hotter halves how long it lasts; fifty takes a decade down to a season. Creep trades time against temperature at a savage exchange rate — and leaves nothing to inspect for until the end.
The instinct is to stiffen it. Stiffening moves the resonance somewhere else and leaves the peak exactly as tall — the height is set by damping and nothing else. And away from resonance, damping does almost nothing.
How that piece was built, including the five things that shipped wrong and the instruments that caught them. The method, not the highlight reel.