Fatigue life estimation for the robust design of truck radiator

Abstract

The growing truck industry, results in larger fleet of trucks serving various transportation needs of the society. On the flip side, the increased sale of vehicles causes environmental pollution affecting the fragile ozone layer. Government and regulatory bodies across the globe enforced tough emission measures to curb the menace. The tougher emission norms translate into design challenges for the truck OEM’s to design lightweight and complex radiator to meet higher operating pressure and durability cycle targets within a tight packaging vehicle space. Robust radiator design is the need of the hour to address the design challenge. A robust design approach coupled with traditional nominal analysis is proposed to determine robust radiator design insensitive to variations. Fatigue Assessment also included in the approach. Nominal design analysis shows that nominal deformation and stress response has 49% reliability and 51% unreliability, which indicates that nominal design does not factor in the variations occurring due to assembly, raw material and manufacturing process. The proposed robust approach identifies robust radiator designs less sensitive to uncertainty and shows 95% reliability. Robust design has 5x higher pressure cycle life as compared against the nominal design. The robust design concept having higher reliability and less sensitive to variations are identified. The approach highlights that robust design has higher pressure cycle durability as compared against the nominal radiator design. Better fatigue life estimation is obtained by using pressure cycle test results.