PSI - Issue 52

Huadong Xu et al. / Procedia Structural Integrity 52 (2024) 52–62 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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3.2. Energy absorption evaluation for various fabrics

Energy absorption of various fabrics are analyzed and evaluated by the methodology established in Section 2.4. In experiments S1, there are 35 layers in UHMWPE fabric target, of which 27 layers are penetrated by projectiles, and the remaining 8 layers are not penetrated. The kinetic energies of the projectiles were 812.8 J which entirely absorbed by fabric. According to the Eq. (1), the specific absorbed energy S of UHMWPE fabric is 99.4 J/(kg/m 2 ) . Using the same method, the specific absorbed energy S of aramid fabric is 89.6 J/(kg/m 2 ) . For the HVI experiments of S3~S8, the depth and volume of the impact crater on witness plate was measured by 3D measuring laser microscope. The comparison results of maximum depth of impact craters on witness plates are shown in Fig. 6.

1400

1311

1200

1091

1055

1000

800

716

600

511

400

Impact Crater Deep (μm)

200

123

0

0

0

Aramid

PE

Quartz

Basalt

Nextel

Al Plate

Carbon Al mesh

Material

Fig. 6. Maximum depth of impact craters on witness plates for various target.

It can be seen from the Fig. 6 that the maximum depth of impact craters of witness plates behind the Al target is the largest, which is 1311 μm. Comparatively, the maximum depth of impact craters of witness plates behind the Quartz fabric is only 123 μm. There is no impact crater on the witness plate of aramid and UHMWPE, because the targets are not penetrated by the projectile. By accumulating the volume of impact craters, the total volume of the crater on the witness plate is obtained. The results are compared as shown in Fig. 7.

80

71.76

20 0 Cumulative crater volume /mm 3 0 40 60

9.6

7.35

0.38

5.19

6.12

0

Aramid PE Quartz Basalt

Nextel

Al Plate Carbon Al mesh

Material

Fig. 7. The total volume of the crater on the witness plate

It can be seen from Fig. 7 that the total volume of the impact crater on the witness plate behind the Al is the largest, which is 71.76 mm 3 . The total volume of the impact crater on the witness plate behind the Quartz fabric target is smaller, only 0.38 mm 3 .