Experimental and numerical study of process-induced defects and theireffect on fatigue debonding in composite joints

Yiding Liu, Xiang Zhang, Stuart Lemanski, Hamed Yazdani Nezhad, David Ayre

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)
33 Downloads (Pure)


Laboratory coupon joints for fatigue debonding tests usually have narrow width and a through-width initialdisbond. However, realistic structural joints are much wider and may contain process-induced defects and ac-cidental damage; both are much smaller than the joint width. Small and discrete damage may behave differentlyfrom the idealised through-width disbond crack. This has brought a question on whether the laboratory couponjoint can accurately represent the fatigue behaviour of wider structural joints. This paper presents an experi-mental and numerical study of fatigue behaviour of a wide bonded lap joint with a process-induced defect ofsemi-circular shape. Fatigue debonding propagation was monitored by ultrasound inspection. Fatigue life waspredicted using a normalised strain energy release rate parameter calculated byfinite element method, and theadhesive material fatigue crack growth rate data measured under single and mixed mode conditions. Simulationof process-induced defect and validation by experiments have brought a better understanding of fatigue de-bonding behaviour in wide joints containing realistic damage. Suggestions are given for fatigue fracture tests ofbonded joints.
Original languageEnglish
Pages (from-to)47-57
Number of pages11
JournalInternational Journal of Fatigue
Early online date22 Mar 2019
Publication statusPublished - Aug 2019


  • Adhesive bonding
  • Composites
  • Disbond
  • Fatigue life prediction
  • Finite element analysis

ASJC Scopus subject areas

  • Modelling and Simulation
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering

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