스틸 휠 굽힘 모멘트 내구시험의 내구신뢰성 개선에 대한 연구 - 스틸 휠 접촉면의 프랫팅 제거 -

A Study for Improvement of Cornering Fatigue Test by Eliminating a Fretting Effect on Steel Wheel to enhance Durability and Reliability

The failure mode of steel road wheels in a vehicle is cracks from ventilation hole through to contact plane on steel wheel's disc plate. But a number of cracks of Cornering Fatigue Limit Test is on contact plane near to wheel nut mounting area, even though it's satisfied with specified cycles. So this paper searches out causes to improve durability and reliability of C.F.T by uni-axial bending moment test. The verified cause is a "fretting" on contact area of steel wheel. In result, this paper suggests a solution to prevent a fretting by inserting a damping shim, 0.7mm between steel wheel contact areas. Therefore this paper makes it possible to move crack position of C.F.T in steel wheel from contact plane to vehicle's failure mode.