A Review of Challenges and Strategies for Modeling Structural Degradation

Structural reliability is commonly approached by evaluating observations of system failures over time. Although this approach has been very useful, it leaves out the insights of the process leading to failure. The understanding of this process, which is referred to as "deterioration", plays a significant role in life-cycle analysis. Degradation depends on the type of structure and the nature of the external or internal demands (i.e., frequency, intensity, mechanism). Therefore, there are important challenges in managing the uncertainty of this process. In this paper, we describe the problem of degradation and the associated uncertainties and suggest different modeling alternatives - among which we emphasize the use of Phase-type distributions as a convenient way to handle problems such as convolution - which emerge frequently in this type of problem.