A new software framework for fatigue life prediction of composite materials under irregular loading

A new software framework for fatigue life prediction of composite materials under irregular loading is presented herein. The entire work is based on a well established methodology for the life prediction of GRP laminates under variable amplitude complex stress states. The process consists of the sequential execution of four main tasks, each one of which copes with a single subproblem in a straight forward manner. The aim of this on-going work is to create a generic software framework that will enable rapid prototyping of various life prediction schemes. Based on the software design, a software library is under development. In the current paper, the software framework is analytically presented. Two different modules are prepared for the first task of the entire methodology. Cycle counting of two different variable amplitude spectra is performed by rainflow counting technique and by simple range-mean technique. Results of both analyses are then processed by routines that solve subsequent steps of the entire methodology in order to predict time up to failure of the material system under consideration, a [0/(+/- 45)(2)/0](T) multidirectional laminate. Theoretical predictions are plotted against experimental data for comparison, and pros and cons of each one of the cycle counting algorithms are discussed.