Link between reinforcement geometry of lamina and delamination resistance of laminates

Piotr Czarnocki

Quarterly No. 2, 2016 pages 103-108

DOI:

keywords: laminates, delamination, fatigue, impact

article version pdf (0.38MB)

abstract The purpose of this research was to determine the relationship between the delamination resistance of fabric reinforced laminates and the areal weight (AW) of reinforcing fabrics and fibre tow orientations. The laminates were reinforced with 2x2 twill fabrics of AW = 161 g/m² and AW = 395 g/m². The tows making up the wefts and warps were oriented at 0°/90° (denoted +) and +45°/45° (denoted x) relative to the delamination propagation direction. The delamination tests were carried out under Mode I and Mode II quasi static and cyclic loading conditions. These tests were complemented with impact tests. For Mode I loading, it was found that GIc was not dependent either on the AW of the fabrics nor on the tow orientations. Similar results were obtained for cyclic loading. Unlike for Mode I, for Mode II loading the highest G_IIc value was found for the laminate reinforced with fabric of AW = 395 g/m² and tow orientation “x” while the lowest one was for laminates reinforced with the same fabric but of a “+” tow orientation. Drop tests indicated that the laminates reinforced with fabrics of the higher AW had better resistance to impact induced damage.