PSI - Issue 52

Leonardo Gunawan et al. / Procedia Structural Integrity 52 (2024) 560–569 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 10. Damage of base plate Model 2 for ൌ ͶͲͲ ƒǤ ƒ† (a) K=1 (b) K=10 (c) K=100 (d) K=1000 N/mm.

Fig. 11. Current acceleration data compared with experiment and simulation of Francesco: (a) using Model 1 for varied values, ሺ„ሻ using Model 2 with ൌͶͲͲ MPa.mm ƒ† ˜ƒ”‹‡† K values. Fig.11. (b) shows the acceleration that occurs from the simulation using Model 2 for G C value of 400 MPa.mm and varied K values. The smaller K value makes the base panel more flexible and reduces the acceleration. The maximum value of acceleration is already lower than the results of the reference simulation (Francesconi, 2009) and is close to the maximum value of the experiment for K = 1 N/mm. It can be said that the results of this simulation are better than the results of the simulation of the referred work. However, the simulation results using Model 2 do not show the second peak as observed in the experiment as well. This is estimated because the boundary condition used in water is non-reflecting outflow. 5. Conclusions The hydrodynamic impact simulation of a hollow box performed by using Model 1, as being done by in the referred work could not predict the damage as observed in the experiment. By modifying the boundary condition of the base plate, which gives an unsymmetric boundary condition to the base plate, as described by Model 2, a closer damage prediction of the base plate was obtained. The fracture energy and cohesive stiffness of respectively 400 N/mm and 1 N/mm seem to be the best guess that give the best results. The model can be developed further to obtain a better representation of the system such as modelling the clamp on all edges using flexible connections, introducing anisotropic properties of the base plate which may arise due to rolling process, using reflecting boundary condition of the water to the vessel to reconstruct the second acceleration peak in the simulation. However, these improvements will increase computational effort.