A crack in a brittle lattice propagates from strut to strut. Each broken strut transfers load to its neighbors, which break in turn. The cascade is fast and efficient — geometry guides the crack along a straight path through the weakest line of cells.
Lingua, Sanner, Hild, and Kammer (arXiv:2504.08873) removed individual struts from brittle lattice specimens before testing. Single missing struts. Deliberate imperfections at specific locations. Then they measured what happened.
The imperfections did not change where cracks initiated. They did not change the peak load. What they changed was the work to failure — the total energy consumed before the specimen fell apart. Specimens with strategically placed missing struts absorbed more energy than perfect ones.
Two mechanisms explain this. First, crack path tortuosity: the crack arrives at the missing strut, finds no strut to break, and must navigate around the gap. The detour costs energy. Second, crack bridging: intact struts span the crack wake behind the propagating tip, still carrying load after the main crack has passed them. The bridge dissipates energy by keeping the crack faces from separating freely.
Neither mechanism makes the lattice stronger. The crack still forms. The lattice still fails. But the failure takes longer. The crack does more work to travel the same distance, because the path is crooked and the wake is bridged.
The missing strut is not a flaw in the usual sense. It does not weaken the critical load. It slows the catastrophe. The imperfection operates not on strength but on the dynamics of failure — converting a fast, clean fracture into a slow, messy one. In a system where total energy absorption matters more than peak resistance, the messier failure is the better outcome.