Effect of Needle Punching Process on a Chopped Strand Mat Composite with an Open Hole

Authors: Daiki Ichikawa, Hiroyuki Hamada, Akio Ohtani

ABSTRACT
The easiest and most reliable joining method is the mechanical joint with a bolt and nut or rivet. However, in the case of composite laminates, mechanical joint properties decrease because of lower interlaminar properties compared to in-plane properties around hole. This study investigated needle punching process with the aim of improving the mechanical properties in the thickness direction of fiber-reinforced plastic composite laminates with an open hole. Needle punching process was applied to glass fiber chopped strand matused as the reinforcement for the composite laminates. Open-hole tensile tests and observations of end cross-sections after the tests were performed. The tensile properties and fracture mechanism of the specimens subjected to needle punching process were investigated. In addition, characteristic distance (a parameter for evaluating resistance to fracture in open-hole tensile test specimens) was also calculated to examine the effects of needle punching process conditions on fracture toughness. Tensile strength was improved by more than 15% by needle punching process. However, when a certain needle punching density was exceeded, the mechanical properties worsened. In addition, characteristic distance increased with increasing needle punching density. Thus, these results suggest that there is an optimal needle punching density with respect to strength and characteristic distance.

Source:

Journal: Open Journal of Composite Materials
DOI: 10.4236/ojcm.2018.83009

(PDF)
Paper Id: 86056 (metadata)

See also: Comments to Paper

About scirp

(SCIRP: http://www.scirp.org) is an academic publisher of open access journals. It also publishes academic books and conference proceedings. SCIRP currently has more than 200 open access journals in the areas of science, technology and medicine. Readers can download papers for free and enjoy reuse rights based on a Creative Commons license. Authors hold copyright with no restrictions. SCIRP calculates different metrics on article and journal level. Citations of published papers are shown based on Google Scholar and CrossRef. Most of our journals have been indexed by several world class databases. All papers are archived by PORTICO to guarantee their availability for centuries to come.
This entry was posted in OJCM. Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *