Paper number 422

ADHESIVE PRESSURE AS FAILURE CRITERION IN MICROMECHANICAL TESTS

Serge Zhandarov, Elena Pisanova, and Konrad Schneider

Institute of Polymer Research
Hohe Str. 6, Dresden 01069, Germany

Summary A new stress-based criterion of interfacial failure in micromechanical tests - critical interfacial normal stress, or adhesive pressure - is proposed. The new criterion has two important advantages: it follows the actual mechanism of crack initiation (in tensile Mode I) and allows to relate interfacial strength to such fundamental physical quantity as thermodynamic work of adhesion. The adhesive pressure values have been experimentally determined for several polymer/fiber model composites; it appeared to linearly depend on the work of adhesion measured independently. The model based on splitting the work of adhesion into the dispersion and acid-base contributions describes the observed relationships.
Keywords micromechanical tests, failure criteria, crack propagation, direct observation, adhesive pressure, work of adhesion, polymer matrices, reinforcing fibers.

Theme : Interface and Interphase ; Mechanical Properties

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