Journal of Auto-vehicle Safety Association ISSN:2005-9396(Print) 자동차안전학회지

This study was conducted in response to the CCPI 2025 report, which ranked South Korea among the lowest countries in greenhouse gas reduction performance, underscoring the need for more robust environmental policies. In particular, research efforts have intensified to address the slowdown in emission reduction within the transportation sector. This study analyzes the structural safety degradation of the main frame caused by the heavy battery used in EV-converted vehicles and proposes an improved subframe mounting method to extend the operational lifespan of such converted vehicles. Although conventional L-shaped brackets offer easy installation and low cost, they pose potential safety risks during long-term operation after conversion. Therefore, a refined subframe cross-sectional design was developed to distribute loads concentrated on the main frame, thereby reducing fatigue deformation and structural failure. The installed subframe was analyzed under three joint conditions—welded, bolted, and hybrid (weld-bolt combined)—to evaluate structural safety. Based on the comparative structural analysis results, the study presents an optimized subframe mounting method suitable for EV-converted light trucks.