PSI - Issue 28

7

Theodosios Stergiou et al. / Procedia Structural Integrity 28 (2020) 1258–1266 T. Stergiou et al. / Structural Integrity Procedia 00 (2019) 000–000

1264

1.2 mm coating

7.0 mm coating

monolithic

Fig. 3. Force-time diagram of normal contact forces in impact region aluminium plate.

3.2 Ballistic performance The measure of interest for the target’s ballistic performance in this work is the ballistic limit. Fig. 4 provides information of the effect of introducing polyurea coating to the thin metallic plate, and the effect of increasing the polymeric layer thickness. Here, the ballistic limit is normalised with that of the monolithic target. Clearly, an improvement of approximately 5% per 1 mm increase in coating thickness is observed. At the same time, emphasis should be given to the fact that improvement in the ballistic limit to the monolithic case is observed in laminate targets with polyurea layer thickness higher than 4 mm.

Fig. 4. Normalised ballistic limit as function of increasing coating thickness.