抄録
This paper deals with the influence of debonding damage between particles and matrix on elastic and elastic-plastic singular fields around a crack-tip in particle-reinforced-composites. Numerical analyses are carried out on a cracktip field in elastic-matrix and elastic-plastic-matrix composites reinforced with elastic particles using a finite element method developed based on an incremental damage theory of particle-reinforced composites. A particle volume fraction and interfacial strength between particles and matrix of the composites are parametrically changed. In the elastic-matrix composites, the complete damage zone, in which all particles are debonded, and the surrounding progressive damage zone develop around a crack-tip. A unique elastic singular field is created on the complete damage zone in addition to the conventional elastic singular field of the non-damaged zone. The macroscopic stress level around a crack-tip is reduced by the debonding damage while the microscopic stress level of the matrix remains no change. In the elastic-plastic-matrix composites, the damage zone develops in addition to the plastic zone due to matrix plasticity, and both the macroscopic and microscopic stress levels around a crack-tip are reduced by the debonding damage. It is concluded from the numerical results that the toughening due to damage could be expected in the elastic-plastic-matrix composites, while it is suspicious in the elastic-matrix composites.
