Embedded Wires Can Concentrate Stress in a Molded Elastomer

What the evidence preview establishes

Internal wire strain-relief loops reduced the load-bearing polyurethane area and concentrated stress at their ends. Cracks then initiated at available weak points: an apparent hard inclusion in one assembly and a molding interface in the other.

Why this case matters

For an overmolded assembly, evaluate the internal load-bearing cross-section rather than external shape alone. Embedded wires, weak wire adhesion, hard inclusions, and molding interfaces can combine into a repeatable fracture plane.