Narrow Results

Fiber-reinforced composites are a class of material with increasing industrial applications. Computer simulations have been used in order to understand the microscopic mechanism which can explain their mechanical behavior and several models have been introduced in the last decade. In this paper we introduce a criterion to define the brittle-ductile transition region in unidirectional fiber-reinforced composites. In order to simulate a fiber bundle, a recently introduced stochastic model is used. The results obtained with our criterion are compared with those obtained by using a self-organized criticality (SOC) approach.

The brittle-ductile transition is a very important phenomenon for polymer toughening. Polypropylene (PP) is often toughened by using rubbers, e.g., ethylene-propylene diene monomer (EPDM) has often been used as a modifier. In this article, the toughening of PP by using a new kind of rubber, known as elastomeric nano-particle (ENP), and the brittle-ductile transition of PP/EPDM/ENP was studied. Compared to PP/EPDM binary blends, the brittle-ductile transition of PP/EPDM/ENP ternary blends occurred at lower EPDM contents. SEM experiment was carried out to investigate the etched and impact-fractured surfaces. ENP alone had no effect on the impact strength of PP, however, with the same EPDM content, PP/EPDM/ENP ternary blends had smaller particle size, better dispersion and smaller interparticle distance in contrary to PP/EPDM binary blends, which promoted the brittle-ductile transition to occur earlier.