Optimization of Dynamic Cornering Fatigue Test Process of Aluminum Alloy Wheels

Abstract

Aluminum wheels are most commonly used wheel type for passenger cars for decades. A356 alloy (including alloying elements of 7% Si and 0.3% Mg) is used and a T6 heat treatment is applied for the wheels. A lot of proofing tests are applied on a wheel in order to ensure its reliability and to guarantee passenger safety. Dynamic cornering fatigue test is the most widely used fatigue performance evaluation method for passenger car wheels. Test is basically applied on the wheel by stretching and bending of the wheel spokes with an oscillating force applied at the far end of a shaft connected to the offset surface of the wheel. This test lasts for 2 to 200 hours depending on the desired number of cycles without a crack or the number of crack initiation cycle (fatigue life). Therefore for a laboratory conducting more than 1500 fatigue tests a year, minimization of test duration without changing applied stress on wheels increases the productivity and improves testing capacity. This study includes the investigations and applications to accelerate the dynamic cornering fatigue test of wheels experimentally. Applied stress levels for regular and accelerated tests were compared by using strain gage recordings experimentally.