Dynamic stress concentrations around a single fiber break in unidirectional composites: a 3D finite element analysis

MUTLU Ç., SABUNCUOĞLU B., Kadioglu F. S., Swolfs Y.

JOURNAL OF REINFORCED PLASTICS AND COMPOSITES, vol.42, no.19-20, pp.1075-1087, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 42 Issue: 19-20
  • Publication Date: 2023
  • Doi Number: 10.1177/07316844221145652
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.1075-1087
  • Keywords: carbon fiber, polymer-matrix composites, finite element analysis, dynamic stress concentrations, fiber distribution, REINFORCED COMPOSITES, STRENGTH MODELS, TENSILE-STRENGTH, FAILURE, REDISTRIBUTION, PREDICTION, MATRIX
  • Middle East Technical University Affiliated: Yes


When a fiber break occurs in longitudinal tension of a unidirectional composite, dynamic stress concentrations arise, which can be different from the ones found considering only static loading. The current paper analyzes the dynamic stress concentration factors (SCF) around a fiber break in unidirectional carbon fiber/epoxy composites. 3D finite element models with random and hexagonal fiber distributions were analyzed to investigate the evolution of stress concentrations as a function of time and position. The results indicate that dynamic effects result in much higher SCFs with a larger effective area around the broken fiber. The increase of SCFs in the closest fibers was determined to be larger for lower fiber volume fractions due to the presence of dynamic effects. Similar to the static case, a lower volume fraction causes higher maximum dynamic SCF in random packings. Results also support the high prevalence of coplanar cluster breaks observed in the experiments.