Fracture Behavior of Long Glass Fiber Reinforced PP Sheets With Hole

Abstract

Recently, owning to the increasing concerns on the environment, lightweight materials representative by composite are being considered to be used in primary structure components in particular in vehicle instead of metal. In order to enhance the mechanical property in particularly tensile property, at current study, stampable sheets (glass mat which were fabricated by punch knitted technology) were adopt to make glass mat reinforced thermoplastic PP (GMT). In the paper, three kinds of specimens including two GMT which have glass fiber weight percent 40 and 20 wt% respectively and a LFT (normal long fiber reinforced thermoplastics PP) which has glass fiber 40wt% were fabricated and tensile tested. The mean fiber length of GMT and LFT were 6.67 and 1.37 mm, respectively. For tensile test, it was observed that the modulus of 40GMT and 40LFT were similar. However, it was found that 40GMT specimens have better tensile strength than 40LFT specimens. In the case of different glass fiber content, 40GMT had more than two times higher value than 20GMT in both tensile modulus and tensile strength. Referring to the effect of hole on the tensile property of GMT and LFT, it was found that the notched tensile strength of both GMT and LFT decrease when W/d equal to 2.0. On the other hand, for W/d equal to 2.5 and 3.0 have no effect to tensile strength.