Experimental analysis and thermal topology optimization of brake disc under emergency braking

Emergency braking exposes brake discs to intense, uneven thermal loads, threatening structural integrity and braking reliability. However, conventional rib configurations often lack sufficient thermal robustness, highlighting the need for structurally optimized designs that ensure thermal stability under extreme operating conditions. To address this, we propose a novel temperature-driven topology optimization framework that enables localized structural optimization based on experimentally validated thermal demands. This methodology is grounded in full-scale brake tests at initial speeds of 350 and 400 km/h, and a coupled numerical model was developed, demonstrating high agreement with experimental measurements. The results indicate that increasing braking speed exacerbates thermal shock, resulting in extreme temperatures and pronounced thermal gradients within the brake disc. The observed temperature field was partitioned into distinct thermal zones, which served as direct input for the proposed optimization strategy. Using the Solid Isotropic Material with Penalization (SIMP) method, the rib structure was reconfigured to target these localized heat loads. The optimized disc (Disc P) achieves a 16.65% reduction in rib mass without sacrificing thermal performance, while Disc Z reduces the temperature difference by 66.58 °C and shrinks the hotspot area (>900 °C) by 16.70%. This work provides a new topology-driven design strategy for the development of advanced brake disc structures operating at higher speeds.