How do you design and analyze bolted joints in composite structures?

Composite bolted joint design involves: Bearing/bypass analysis using methods like Hart-Smith or Yamada-Sun; Failure mode prediction (net tension, bearing, shear-out, cleavage) using semi-empirical strength envelopes; Finite element analysis with contact and progressive damage for detailed assessment; Design parameters including w/d > 4, e/d > 3, t/d optimization; Filled hole tension and open hole compression considerations; Protruding head vs countersunk fastener effects; Joint stiffness and load sharing; and Temperature/moisture effects on bearing strength. Testing requirements include single-fastener characterization and multi-fastener validation. Design must account for 20-40% strength reduction from notch sensitivity compared to unnotched composite.