Theoretical Study of the Stress Transfer in Single-Fibre Composites. Part II. Partially Debonded Fibre-Matrix Interface

1994 ◽  
Vol 3 (3) ◽  
Author(s):  
S.Y. Fu ◽  
S.H Li ◽  
S X Li ◽  
G.H. He ◽  
B.L. Zhou
Keyword(s):  
Theoretical Study ◽  
Stress Transfer ◽  
Single Fibre ◽  
Matrix Interface ◽  
Fibre Composites ◽  
Fibre Matrix

An Energy-Based interpretation of Interfacial Adhesion from Single Fibre Composite Fragmentation Testing

1993 ◽  
Vol 2 (5) ◽  
pp. 096369359300200 ◽  
Author(s):  
H.D. Wagner ◽  
S. Ling
Keyword(s):  
Interfacial Adhesion ◽  
Mechanical Characteristics ◽  
Interfacial Shear Strength ◽  
Fibre Composite ◽  
Stress Transfer ◽  
Single Fibre ◽  
Transfer Length ◽  
Fragmentation Test ◽  
Energy Balance Approach ◽  
Fibre Matrix

An energy balance approach is proposed for the single fibre composite (or fragmentation) test, by which the degree of fibre-matrix bonding is quantified by means of the interfacial energy, rather than the interfacial shear strength, as a function of the fibre geometrical and mechanical characteristics, the stress transfer length, and the debonding length. The validity of the approach is discussed using E-glass fibres embedded in epoxy, both in the dry state and in the presence of hot distilled water.

New theoretical model of stress transfer between fibre and matrix in a uniaxially fibre-reinforced composite

1989 ◽  
Vol 425 (1868) ◽  
pp. 215-244 ◽  
Keyword(s):  
Boundary Conditions ◽  
Coulomb Friction ◽  
Stress Transfer ◽  
Matrix Crack ◽  
Matrix Interface ◽  
Friction Law ◽  
Reinforced Composite ◽  
Coulomb Friction Law ◽  
Frictional Slip ◽  
Fibre Matrix

A new analytical method has been developed that can predict the stress transfer between fibre and matrix in a uniaxially fibre-reinforced composite associated with either a single matrix crack or a fibre break. Account is taken of thermal residual stresses arising from a mismatch in thermal expansion coefficients between the fibre and matrix. In addition Poisson ratio mismatches are also taken into account. The theoretical approach retains all relevant stress and displacement components, and satisfies exactly the equilibrium equations, the interface conditions and other boundary conditions involving stresses. Two of the four stress-strain-temperature relations are satisfied exactly, whereas the remaining two are satisfied in an average sense. The required non-interface displacement boundary conditions are also satisfied in an average sense. The general representation is used to solve three types of stress transfer problem. A matrix crack and a broken fibre are analysed for the case when there is perfect bonding between fibre and matrix. The third type of problem takes account of frictional slip at the interface governed by the Coulomb friction law. The approximate analytic approach described in this paper, and the preliminary numerical predictions presented, indicate that the stress transfer between fibres and matrix in a unidirectional fibre-reinforced composite, loaded in tension, can now be investigated theoretically in more detail than before. The paper includes some discussion of singularities in the stress fields, which are smoothed by the averaging techniques employed in the analysis. The analytical approach has enabled the development of a micro-mechanical model of frictional slip at the fibre-matrix interface based on the Coulomb friction law, which is more realistic than assuming that the interfacial shear stress is a constant. Predictions are presented of the stress distributions along the fibre-matrix interface and, in particular, it is shown how the length of the frictional slip zone is related to applied strain, friction coefficient, fibre volume fraction and the difference between the test and ‘manufacturing’ temperatures. An indication is given of many other areas of composite modelling where the new theory will be applied.

Single-fibre Broutman test: fibre–matrix interface transverse debonding

1999 ◽  
Vol 30 (12) ◽  
pp. 1423-1434 ◽  
Author(s):  
C Ageorges ◽  
K Friedrich ◽  
T Schüller ◽  
B Lauke
Keyword(s):  
Single Fibre ◽  
Matrix Interface ◽  
Fibre Matrix
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