Fatigue analysis of a post-buckled composite single-stringer specimen taking into account the local stress ratio Articles uri icon

publication date

  • March 2020

start page

  • 1

end page

  • 9

issue

  • 108000

volume

  • 193

International Standard Serial Number (ISSN)

  • 1359-8368

Electronic International Standard Serial Number (EISSN)

  • 1879-1069

abstract

  • The fatigue life prediction of post-buckled composite structures represents still an unresolved issue due to the complexity of the phenomenon and the high costs of experimental testing. In this paper, a novel numerical approach, called "Min-Max Load Approach", is used to analyze the behavior of a composite single-stringer specimen with an initial skin-stringer delamination subjected to post-buckling fatigue compressive load. The proposed approach, based on cohesive zone model technique, is able to evaluate the local stress ratio during the delamination growth, performing, in a single Finite Element analysis, the simulation of the structure at the maximum and minimum load of the fatigue cycle. The knowledge of the actual value of the local stress ratio is crucial to correctly calculate the crack growth rate. At first, the specimen is analyzed under quasi-static loading conditions, then the fatigue simulation is performed. The results of the numerical analysis are compared with the data of an experimental campaign previously conducted, showing the capabilities of the proposed approach.

subjects

  • Aeronautics

keywords

  • composite structures; delamination; skin-stringer separation; fatigue; post-buckling; local stress ratio