How long does a tug on the middle bead take to reach the pinned ends? The center bead drops from y = 5 and drags its neighbors after it: the bead beside the center moves within 2 ticks, the bead beside each amber pinned end after about 40.
Try this Choose the Hanging chain preset (gravity 9.5, spring-stiffness 70, spring-damping 2). The chain drops, bounces and settles into a sagging curve with the center bead near y = −11; the swings take a few simulated minutes to die out.
About this model A chain of beads joined by springs is the usual discrete stand-in for a string. In this one the springs start at their rest length, so there is no tension until the chain bends: small sideways displacements barely stretch the springs, and the motion is strongly nonlinear rather than a set of standing waves.
Eleven beads sit 4 units apart from x = −20 to 20; the two end beads have zero mass and stay fixed. Setup lifts the center bead by displacement (default 5). Each spring pulls on both ends with spring-stiffness × (length − 4) plus spring-damping × the rate its length changes. Each tick applies gravity × mass downward to every bead and advances the mechanics library by 1/30 s, in substeps of 1/240 s or less. Beads are point masses with no collisions, and nothing keeps them on the board.
spring-stiffness, spring-damping and displacement apply at setup (press Reset); gravity is read every tick. Damping acts only along each spring, so it removes stretching motion quickly but does little against sideways swinging: at spring-damping 6 the center still moves about ±2 units two minutes later.
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