Author : Shahwaiz Hassan Shah and Muhammad Usama Zafar

Thermo mechanical stresses play an important role in the failure of critical parts of many applications like turbines, power plants, hot rolling mills and especially in automotive industry. Thermal fatigue is the major cause of this damage of metals due to thermal cycling. In automotive industry thermal fatigue occurs in engines due to variation in temperature during intake and exhaust stroke. This gradual thermal cycling damage the engine parts especially engine cylinder liner which reduces the service life of an engine. So, it is very important to estimate the thermal fatigue life of engine cylinder liner material. In this research work, thermal fatigue life of engine cylinder liner material grey cast iron has been investigated. A wedge-shaped specimen is prepared from sand casting and used for the experimentation of thermal fatigue. Thermal fatigue experiments are performed between 750C2800C thermal cyclic ranges. Crack initiation and propagation are investigated experimentally on one edge of wedge shape specimen and validate of these propagations of cracks with numerical simulation using ABAQUSTM software.

Keywords: Thermal fatigue, thermal stress, mechanical stress, crack initiation, crack propagation, crack saturation