PSI - Issue 5

Jung Min Sohn et al. / Procedia Structural Integrity 5 (2017) 935–942 Aditya Rio Prabowo et al. / Structural Integrity Procedia 00 (2017) 000 – 000

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ship and upper part of the struck ship was not found. This situation may become more serious disaster if the bulbous bow of the striking ship is bigger or has blunt geometry. Impact with a blunt bulbous bow is predicted to produce bigger hole on the side structure as failure can be more extensively distributed to wider area of the side structure. It is concluded from these illustrations that as increment of draught on the struck ship and vice versa, the hole on the lower part of the struck ship becomes more significant than damage on the upper structure that are found to be none on the over deck-collision . This condition can be met if the striking ship possesses a bulbous bow on it.

pper eck

pper eck

(m)

(m)

ar eck

ar eck

Tank top

Tank top

Fig. 6. The damage extent of the shell-collision model.

Fig. 7. The damage extent of the deck-collision model.

pper eck

Failure strain: Lehmann and Peschmann criterion

(m)

Deck-collision

Over deck-collision

ar eck

Tank top

Shell-collision

Fig. 8. The damage extent of the over deck-collision model.

Fig. 9. The plastic strain of the struck ship during collision.

In crushing process, the behavior of material in experiencing strain can be considered as an important part in failure assessment. Growth of this damage behavior happens whenever the material is actively yielding, i.e. whenever the state of stress is on the yield surface. As presented in Fig. 9, material will reach the failure condition during strain accumulation and as defined by failure strain. The strain in this work is taken from the global element that experiences maximum strain. Based on this results, it is obtained that the over deck-collision experienced the earliest yielding than other collision models and it can be estimated that the element that experienced maximum strain in this scenario was located near the impact between the bulbous bow and struck ship. This work presented a series of results from collision analyses. The calculations were successfully conducted by the finite element as numerical method. The results indicated a longitudinal component on the side structure has remarkable role in resisting penetration of the striking ship during side collision. The largest tearing was observed to occur on the lower part of the struck ship during penetration of the bulbous bow. Impact between a striking ship which has a blunt bulbous bow and the struck ship in the full load condition (position of the struck ship is lower than the striking ship) may cause more massive damage on the struck ship structure. Crashworthiness criteria in terms of the 5. Conclusions