PSI - Issue 26

Costanzo Bellini et al. / Procedia Structural Integrity 26 (2020) 120–128 Bellini et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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laminate, that one with five layers bonded with adhesive, are presented in Fig. 8. The failure of the long beam specimen was caused by the breakage of the fibre, but breakage can be observed in the aluminium sheet too (Fig. 8a and 8b, respectively). However, the aluminium sheet failure was observed only in two specimens out of four. As concerns the short beam specimen, also in this case, as the type A specimen, the interfaces between the different materials resulted undamaged, while the failure was caused by intra-layer and inter-layer delaminations, as visible in Fig. 8c and 8d, respectively. Finally, the micrographies relevant to the laminate with five layers bonded with prepreg resin, the type D one, are reported in Fig 9.

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c

b

d

Fig. 6. Type A specimen micrographies: a-b long beam, c-d short beam.

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b

c

d

Fig. 7. Type B specimen micrographies: a-b long beam, c-d short beam.

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c

d

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Fig. 8. Type C specimen micrographies: a-b long beam, c-d short beam.

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b

Fig. 9. Type D specimen micrographies: a-b long beam.