PSI - Issue 13

Israr ul Haq et al. / Procedia Structural Integrity 13 (2018) 1955–1960 Israr ul Haq / Structural Integrity Procedia 00 (2018) 000–000

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Fig. 2 Experimental and Numerical Simulation Results for Spherical Projectile at Ballistic Limit

2.3. Analysis of Conical Projectile After validation of finite element mode for spherical projectile with the experiment, conical projectile model is built in the same way. Fig. 3 shows four configurations, i.e., apex angles. Dimensions of all the projectile shapes are selected in such a way that weight and diameter of each projectile remains the same as the spherical projectile used in the experiment. Finite element models for all four projectiles are build similar to Fig. 1. Mesh size and all other parameters are kept same as in spherical projectile. 3. Results and Discussion Fig. 4 shows different views of Inconel-718 target deformation by various apex angle projectiles. Fig. 4 (a) to (d) shows side view of penetration of target by different projectiles. It can be seen that for apex angles , main deformation mode is petalling whereas for apex angle , ejected plug from the target can also be seen. Fig. 4 (e) to (h) shows back view of the target after perforation by various apex angle conical projectiles. It can be seen that number of petals all the projectiles are 4 whereas for degree apex angle, number of petals are 5. This result is consistent with the study presented in (Kpenyigba, Jankowiak, Rusinek, & Pesci, 2013). It has been concluded that increase in apex angle decreased number of petals formed. Fig. 4 (i) to (l) shows front view of the target struck by different conical projectiles. It can be seen that increase in cone apex angle increases crack length of the target in radial direction. For there is circumferential crack growth as well apart from radial growth at the base of petals. Fig. 4 (m) to (p) shows side view of the target after deformation. It can be seen that with the increase in apex angle, curling of petals decreases and bending of target plate in increased. Fig. 5 (Left) shows plot for variation in ballistic limit with increase ballistic limit. It can be seen that with the increase in apex angle ballistic limit is increased from from . For apex angle , ballistic limit dropped to 136 m/s because of shear plugging mode of deformation along with petalling.

Fig. 3 Geometry shapes (a) 40 Degree Cone; (b) 60 Degree Cone; (c) 80 Degree Cone; (d) 100 Degree Cone