In situ X-Ray Tomography for Analyzing Mechanical Damage in Structural Materials

Fatigue failure is a phenomenon resulting from the application of cyclic loading. Cyclic loading may be due to the rotation of components, such as shafts, or variable loadings caused by, for example, changes in pressure or temperature during operation. Fatigue is considered as one of the major causes of failure in oil, gas, petrochemical and manufacturing industries in Saudi Arabia. Fatigue damage parameters are classified based on the definition of the parameter that quantifies fatigue damage. This can be stress, strain or energy. In a critical plane approach, parameters are evaluated at specific planes; hence, both the fatigue life as well as the crack orientation can be predicted. Critical plane models have been shown to provide reasonable fatigue estimation. However, models that are based on completely different critical plane assumptions, such as normal and shear, often produce similar fatigue life estimation. Such contradiction suggests that critical plane concept might need revision. In situ x-ray tomography can provide in-depth details of the fatigue damage process. These details will enhance our understanding of fatigue process and they will enable us to examine and/or improve existing fatigue damage models that will be reflected on the estimation of fatigue life. Saudi Arabia is expected to construct 16 nuclear power reactors over the next20 years. X-ray tomography is an essential non-destructive evaluation technique for analyzing materials used for nuclear reactors. In addition, this method is proven to be an effective method for studying damage in composite materials and for studying corrosion in metals. Both composites and corrosion are strategic research areas in Saudi Arabia. In this proposal, the team intends to develop a state of the art x-ray tomography system at KFUPM lab. This facility will be used to study the evolution of fatigue damage in strategic materials for the Kingdome of Saudi Arabia.