Influence of ply orientation on mode I interlaminar fracture toughness of woven carbon and glass composites

• Published in: Mechanika (Kaunas, Lithuania : 1995) no. 2; pp. 31 - 36
• Main Authors: Kersiene, N, Ziliukas, A, Kersys, A
• Format: Journal Article
• Language: English
• Published: 01.01.2010
• Subjects: Berries; Cantilever beams; Carbon; Crack initiation; Criteria; Damage; Dangerous; Delaminating; Delamination; E glass; Fracture mechanics; Fracture toughness; Glass; Glass fiber reinforced plastics; Interlaminar; Nonlinearity; Offsets; Planes; Ply orientation; Polymer matrix composites; Reinforcement; Stacking
• ISSN: 1392-1207

The paper presents the study of the influence of ply orientation on mode I interlaminar fracture toughness of woven carbon and glass composites. Double cantilever beam test of mode I as performed on twill woven car-bon/epoxy and E-glass/epoxy composite systems. Specimen stacking sequences with initial delamination at the angles of 0//,0//90, + 45//- 45 and 0//+ 45 were used. To define the exact instant of crack initiation the criteria of nonlinearity (NL) and 5% offset or maximum force criteria were used. The conservative Berry method and nonlinearity criterion that enable to determine the increase of the damages in microlevel were chosen for the result estimation. The evaluation of the influence of the layer reinforcement angles on G(IC) disclosed that the reinforcement of the layers in the delamination plane at the angles of 0//0 and especially 90//0 was the most dangerous. Thus in the structures the layers should be reinforced at the angles of 0//+45 because G(IC) was by 1.4 times greater if compared with the instance of 0//0 angles.