• Journal of Auto-vehicle Safety Association
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• v.14 no.3
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• pp.30-34
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• 2022

The CFT(Cornering Fatigue test) and RFT(Radial Fatigue Test) are tests for evaluating the endurance of the disc and rim region of the wheel. In recent, automobile wheel safety standards have been revised and the applied load and target life criteria are different from existing conditions. The verification evaluation of all wheels requires a lot of time and cost. In this study, the endurance severity of each test was compared through strain-life approach by selecting 4 steel and 8 aluminum wheels.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1326-1330
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• 2008

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.

• Journal of Auto-vehicle Safety Association
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• v.8 no.1
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• pp.26-30
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• 2016

The steel road wheel on ventilation holes was cracked in the vehicle durability test. But the component durability test by uni-axial, CFT(Cornering Fatigue Test) and RFT(Radial Fatigue Test) had been satisfied. That is, the uni-axial component test could not forecast the crack of vehicle. Therefore this study developed the bi-axial test mode to reflect a vehicle condition(to reflect both vertical and lateral force simultaneously) based on real load data which was measured in Europe and China and developed CAE simulation too. It reproduced the cracks same as vehicle's and verified by bi-axial test machine in the LBF(Fraunhofer Institute for Structural Durability and System Reliability) durability research center in Germany. Finally this the durability CAE simulation by using HMC(Hyundai Motor Company)'s the bi-axial test mode predicts feasibly the steel wheel's durability performance before vehicle durability test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.739-744
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• 2017

Elastic deformation and fatigue damage can cause the permanent deformation of a kart's frame during turning, affecting the kart's driving performance. A kart's frame does not contain any suspension or differential devices and, therefore, the dynamic behavior caused by torsional deformation when driving along a curve can strongly affect these two kinds of deformations. To analyze the dynamic behavior of a kart along a curved section, the GPS trajectory of the kart is obtained and the torsional stress acting on the kart-frame is measured in real time. The mechanical properties of leisure and racing karts are investigated by analyzing their material properties and conducting a tensile test. The torsional stress concentration and frame distortion are investigated through a stress analysis of the frame on the basis of the obtained results. Leisure and racing karts are tested in each driving condition using driving analysis equipment. The behavior of a kart when being driven along a curved section is investigated through this test. Because load movement occurs owing to centrifugal force when driving along a curve, torsional stress acts on the kart's steel frame. In the case of a leisure kart, the maximum torsional stress derived from the torsional fatigue limit was found to be 230 MPa, and the torsional fatigue limit coefficient was 0.65 when driving at a speed of 40 km/h. Furthermore, the driving elements during the cornering of a kart were measured based on an actual auto-test after installing a driving measurement system, and the driving behavior of the kart was analyzed by measuring its vertical displacement.