On the effects of stitching in CFRPs—I. mode I delamination toughness

Experimental optimization of the impact energy absorption of epoxy–carbon laminates through controlled delamination

“…When a composite structure is impacted, delamination often occurs, which seriously reduces the load bearing capacity of the laminate especially under compressive loads [5]. Therefore, several methods have been developed to improve the interlaminar strength and interlaminar fracture toughness of composite laminates, such as matrix toughening [6][7][8][9], through-thickness stitching [10][11][12][13][14], Z-pinning [15,16], and interleaving [17][18][19][20][21][22][23][24][25] and short-fibre interlaminar reinforcement [25]. Most of the above mentioned methods have been reviewed by Kim and Mai [26], who also pointed out the key role played by the fibre-matrix interfacial shear strength in determining the interlaminar resistance of composite laminates.…”

Improvement of Mode I Interlaminar Fracture Toughness of Stitched Glass/Epoxy Composites

“…The gradient in the linear region for sample group A1 (0) was bigger than that for all the MLS groups. MLS; for the MLS groups: B1 [20], C1 [10], D1 [5], E1 (10 × 10), and F1 (5 × 5), the NL displacement points are close to each other and appear near the maximum load point. The crack propagation proceeded steadily as shown in Fig.…”

“…Hence, these groups' load-displacement curves have a characteristic jagged shape and the average maximum load and displacement values were variable. In general, sample groups B1 [20], C1 [10], and D1 [5] which were stitched in one column have low values of load and displacement. Amongst these groups, B1 [20] and C1 [10] have the lowest maximum average load of 311.6 N with displacements of 16.3 and 17.0 mm respectively.…”

“…Among these reinforcement techniques, researchers have concluded that stitching is an effective reinforcement technique to limit crack propagation and to minimise delamination within multilayered textile composites [3][4][5][6][7][8][9][10]. The awareness of stitching as a technique for through thickness reinforcement has increased rapidly during the last three decades.…”

Development Of Multistitched Three-Dimensional (3D) Nanocomposite And Evaluation Of Its Mechanical And Impact Properties

“…Stitching improved the damage resistance properties of woven composite structure under blast load and ballistic impact load [24]. It was reported that stitching fiber base composites in the through-the-thickness direction enhanced the Mode I and Mode II interlaminar fracture toughness, which was experimentally determined by using double cantilever beam and an end-notched flexure test, respectively [25,26]. The critical strain-energy release rate increased because the stitching bridge the delamination [27,28].…”