How do you develop and validate thermal durability test procedures for underhood and exhaust components?

Thermal durability development: 1) Duty cycle definition - capture worst-case thermal events from customer usage and engineering drives (towing, mountain grades, high-speed sustained, hot soak); 2) Temperature characterization - instrument all critical locations during representative maneuvers; 3) Accelerated schedule design - increase cycle frequency while maintaining peak temperatures and thermal gradients; 4) Material degradation correlation - validate acceleration by comparing material properties (tensile, elongation, discoloration) between accelerated and real-time aged parts; 5) Component validation - confirm performance retention after thermal exposure. Considerations include thermal fatigue cycles, oxidation exposure, and combined effects with mechanical loads. Fixture design for rig testing must replicate vehicle thermal boundary conditions including adjacent components and airflow patterns.