Running Head: Engineering
Failure Analysis regarding Thermal Fatigue Name: Institution: Course: Tutor: Date:
Failure Analysis regarding Thermal Fatigue Fatigue may be defined as damage incurred on the surface or structure of a machine or material due to excessive weight or load. In some cases, this may also result due to temperature variations. In such cases, machines or tools involve thermal cycles throughout their use (Bathias, 2005). These thermal cycles eventually stress the surface of machine or tool resulting in premature fractures usually known as thermal fatigue (Cleveland, 2006). Thus thermal fatigue is basically the premature fracture brought about by temperature changes as a result of cyclic stresses. In composite systems which involve the use of thermal cycles, it is usually a serious threat. Fractures interfere in the smooth working of machines thus hindering the efficiency. Thermal fatigue may also be looked upon as metal fatigue type brought about by repeated cooling and heating (Howell, 2003). This particular phenomenon is quite common in turbines in which case cooling or heating occurs every time when power setting is changed. Thermal fatigue issue may further be explained as exhaustion which comes up due to rapid decrease or increase in temperature in the course of the various operations (Day, 1998). The temperature variations bring about dimensional changes which are not uniform within materials, thus resulting in fractures or distortions (Hancock, 2001). Following figure illustrates the concept of thermal fatigue more clearly:
Thermal Fatigue failure in a Tube (U-bend section)
Failure Analysis Failure analysis is a complex process of determining the various causes of failure in the process of development along with designing ways and methods to prevent such acts in future. The purpose of failure analysis is entirely positive and is applied to all types of materials. Failure analysis regarding thermal fatigue is very essential due to the fact that it enables individuals to comprehend root causes of thermal fatigue along with effects and ways through which they may be controlled. As a result of the various detrimental outcomes which are associated with thermal fatigue like ineffective operations, it is essential for engineers or those who operate the various machines to find out suitable mechanisms of ensuring that such occurrences are minimized.