Interface debonding

Kim, J.K. (1997). Stress transfer in the fiber fragmentation test, part IFF. Effects of interface debonding and matrix yielding. J. Mater. Sci. 32, 701-711. 

The interface debond criterion used in this analysis is based on the concept of fracture mechanics where the strain energy release rate against the incremental debond length is equated to the interface fracture toughness, Gk, which is considered to be a material constant... 

Substituting the solutions for the three major stress components determined in the bonded and debonded regions, a fiber-matrix interface debond criterion is derived as... 

Based on the shear strength criterion for the interface debonding, the condition for the fully bonded interface requires that the maximum IFSS be obtained at the... 

Fig. 4.11. Plot of interface shear bond strength, ib, as a function of fiber length, 2L. showing the interface debond criteria, according to Eq. (4.71). After Kim et al. (1993b).

Interface debond criterion and partial debond stress... 

To show clearly how and to what extent the parameter, Zmax. varies with the properties of the interface and the composite constituents, a simple fiber pull-out model by Karbhari and Wilkins (1990) is chosen here. This model is developed based on the assumption of a constant friction shear stress, Tfr, in the context of the shear strength criterion for interface debonding. In this model, the partial debond stress may be written as... 

From the discussion presented above, it is clear that the stability of the debond process can be evaluated by a single parameter, Zmax, which is the shortest (remaining) bond length needed to maintain the debond process stable, and is a constant for a given composite system. Therefore, three different interface debond processes are identified in the following totally unstable, partially stable and totally stable debond processes. The schematic plots of the applied stress versus displacement curves are illustrated in Fig. 4.25 for these debond processes. 

Effect of matrix cracking and interface debonding. J. Mater. Sci. 32, 633-641. 

Fiber-matrix interface debonding in mode II shear... 

Fig. 7,6. (a) Transverse impact fracture toughness and (b) interface debond length versus testing temperature for carbon fiber-epoxy matrix composites with and without PVAL coalings on fibers. After... 

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