Effect of fiber array irregularities on microscopic interfacial normal stress states of transversely loaded UD-CFRP from viewpoint of failure initiation

Masaki Hojo, Masaaki Mizuno, Thomas Hobbiebrunken, Taiji Adachi, Mototsugu Tanaka, Sung Kyu Ha

Research output: Contribution to journalArticle

69 Citations (Scopus)

Abstract

A detailed investigation has been carried out to determine the effect of local fiber array irregularities and controlling fiber distribution parameters on microscopic interfacial normal stress states for transversely-loaded unidirectional carbon fiber (CF)/epoxy composites. Linear elastic finite element analyses were carried out for two-dimensional image-based models composed of about 70 fibers. The relationship between the geometrical distribution of two adjacent fibers and the interfacial normal stresses (INSs) is investigated for all fibers in different image-based models. Three boundary conditions for loading were selected: Case A involved cooling from the curing temperature (the difference in temperature was -155 K); Case B involved transverse loading of 75 MPa chosen as an example of macroscopic transverse fracture strength; and Case C involved both cooling from the curing temperature and transverse loading of 75 MPa. High compressive INSs due to the difference in the coefficients of thermal expansion are observed at the location of the shortest interfiber distance for Case A (cooling). High tensile INSs are observed at the location of the shortest interfiber distance and where the fiber alignment angle to the loading direction is small for Case B (loading). For Case C (cooling and loading), the high thermal residual compressive INSs and the high mechanical tensile INSs compensate each other, and the INSs at a short interfiber distance are much lower than those for Case B. These results clearly indicate the importance of the contribution of the thermal residual stresses to the transverse tensile failure initiation of CF/epoxy laminates.

Original languageEnglish
Pages (from-to)1726-1734
Number of pages9
JournalComposites Science and Technology
Volume69
Issue number11-12
DOIs
StatePublished - 2009 Sep 1

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Carbon fiber reinforced plastics
Fibers
Cooling
Carbon fibers
Curing
carbon fiber reinforced plastic
Thermal stress
Temperature
Laminates
Thermal expansion
Fracture toughness
Residual stresses
Boundary conditions
Composite materials

Keywords

  • B. Debonding
  • C. Finite element analysis (FEA)
  • C. Residual stress
  • C. Transverse cracking
  • Micromechanics

Cite this

Hojo, Masaki ; Mizuno, Masaaki ; Hobbiebrunken, Thomas ; Adachi, Taiji ; Tanaka, Mototsugu ; Ha, Sung Kyu. / Effect of fiber array irregularities on microscopic interfacial normal stress states of transversely loaded UD-CFRP from viewpoint of failure initiation. In: Composites Science and Technology. 2009 ; Vol. 69, No. 11-12. pp. 1726-1734.
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Effect of fiber array irregularities on microscopic interfacial normal stress states of transversely loaded UD-CFRP from viewpoint of failure initiation. / Hojo, Masaki; Mizuno, Masaaki; Hobbiebrunken, Thomas; Adachi, Taiji; Tanaka, Mototsugu; Ha, Sung Kyu.

In: Composites Science and Technology, Vol. 69, No. 11-12, 01.09.2009, p. 1726-1734.

Research output: Contribution to journalArticle

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AU - Hojo, Masaki

AU - Mizuno, Masaaki

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AU - Adachi, Taiji

AU - Tanaka, Mototsugu

AU - Ha, Sung Kyu

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