PSI - Issue 8

V. Dattoma et al. / Procedia Structural Integrity 8 (2018) 444–451 Author name / Structural Integrity Procedia 00 (2017) 000–000

446

3

picture is an idealized representation of the geometry, since the realistic result is a stepped variation of the curvature of the fiber, rather than a gradual deviation.

Table 1. Laminate lay-up Identification specimen series

Lay-up

number of plies

50-33-24-WD10 50-33-24-WD20 50-33-24-WD40 17-67-24-WD10 25-50-16-WD10

[45,90,0,0,-45,0,0,-45,0,0,90,45]sym [45,90,0,0,-45,0,0,-45,0,0,90,45]sym [45,90,0,0,-45,0,0,-45,0,0,90,45]sym [45,0,-45,45,90,-45,45,0,-45,45,-45,90]sym

24 24 24 24 16

[45,0,-45,90, 45,0,-45,90]sym

Fig. 1. Typical section of the reduced section with the introduction of the artificial wrinkle.

The geometrical parameters that define the wrinkles have been identified in Figure 2 and have been measured on each specimen. The averaged results of the measurements are reported in Table 2, while the transversal aspect of a representative specimen of each series is reported in Figure 3.

Fig. 2. Geometry of artificial wrinkles.

Table 2. Measured parameters defining the artificial wrinkles. Specimen Set W/D nominal W/D measured t [mm] s [mm]

W [mm] 15.10 15.28

D [mm]

α [°] 5.4 2.4 1.9 5.6 5.6

50-33-24-WD10 50-33-24-WD20 50-33-24-WD40 17-67-24-WD10 25-50-16-WD10

10 20 40 10 10

12.4 23.8 50.9 12.3 14.2

4.64 4.52 4.68 4.58 3.14

3.43 3.88 3.78 3.20 2.10

1.21 0.64 0.90 1.38 1.04

45.8

16.95 14.73