Modelling of Fatigue Damage in Aluminum Cylinder Heads

Abstract

Car manufacturers are very much concerned with thermal fatigue damage that may cause Diesel engine to fail after a few thousand cycles on the test bench and under severe operating conditions. The alternative heating and cooling of the operative Diesel engine generates fatigue cracks, initiating from the fire deck of the cast aluminum cylinder head, which can lead ultimately to engine failure. We present here the modelling of the fatigue damage in aluminum cylinder heads : we describe the constitutive equations and the results of fatigue crack growth rate measurements. These results are used with the weight function approach to predict crack propagation lifetime of cylinder heads.