Fatigue life visualisation

Abstract

The visualization of cycle number (fatigue life) approach before crack initiation in seamless cylinders for natural gas provides a new, complex view of limit states in material fatigue. Method, described in the article, includes amplitudes, average values of stress and strain tensors, and load history. We are able to see cycle number distribution before the crack initiation and therefore it is possible to decide much more effectively on relevant modifications in the seamless cylinder design. In this paper we described the method of cycle number before the crack initiation calculation and offered an appropriate iterative operation. Material fatigue model is highly sensitive to input data and very often a divergent solution occurs, and that is a problem the proposed calculation method solves. Thanks to such visualization approach we are now able to assess limit states in material fatigue much more effectively.