Explain the concept of load path design in frontal crash structures.

Frontal crash load paths are designed to absorb energy progressively while maintaining cabin integrity. Primary load paths include longitudinal rails (main energy absorbers, designed to fold predictably), shotgun members, and subframe connections. Secondary paths distribute loads to rocker panels and A-pillars. Design principles include: controlled crush initiators (notches, material transitions), staged deformation (softer front, stiffer rear), load spreading through cross-members, and firewall intrusion management. FEA simulations model progressive failure using explicit solvers at multiple crash speeds.