TITLE:
A Comparison between Forming Behaviours of Two Pre-Consolidated Woven Thermoplastic Composites
AUTHORS:
N. A. Zanjani, S. Kalyanasundaram
KEYWORDS:
Woven Composite, Stamp Forming, Self-Reinforced Polypropylene, Glass-Fibre Reinforced Polypropylene, Failure
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.3 No.7,
July
16,
2015
ABSTRACT: This paper presents the results of an
investigation on stretch forming behaviour of two consolidated woven thermoplastic
composites: a self-reinforced polypropylene (SRPP) and a glass-fibre reinforced
polypropylene (GRPP) composite. A custom-built press with a hemispherical punch
was employed to deform composites’ specimens possessing different aspect ratios
into an open die. The induced strains on the outer surface of specimens were
measured continuously through two high speed, high resolution CCD cameras by
employing a Digital Image Correlation (DIC) technique. The strain paths at
three different locations on the surface of specimens were compared to
elucidate the effect of fibre and matrix on the formability of a woven
composite. The fractured surface of specimens was investigated to reveal the effect
of fibre mechanical properties on failure morphologies in woven composites. It
was found out that the main mode of failure in GRPP is fibre fracture while
observed failure morphologies in SRPP were a complex combination of different
failure mechanisms. It was revealed that the combination of applied boundary
conditions and specimen’s width determines the effective forming mechanisms.