A theoretical study of micro-structural size effect on crack extension in composite materials

Abstract

Effect of micro-structural size on the crack extension in composites is theoretically studied by the use of a simplified two-dimensional crack model in uni-directionally reinforced composites. The model assumes that the plastic deformation occurs in the matrix layer ahead of the main crack and that micro-crack initiation in the plastic region leads to the global fracture of the composites. The continuous dislocations method is introduced, and used for the analysis of the crack and plastic fields in composites. The micro-structural size effect is discussed in terms of the ratio of reinforcement thickness to the possible in situ crack size.

Keywords:

• composite
• crack
• fracture
• size effect
• micromechanics
• dislocation