PSI - Issue 27

Aditya Rio Prabowo et al. / Procedia Structural Integrity 27 (2020) 77–84 Prabowo et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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(a) (b) Fig. 6. Experiment of ship structure against explosion: (a) arrangement of rectangular strain gauges and (b) strain components at the gauges 4 – 6# (Ming et al., 2016).

Fig. 7. Crack propagation on the steel structure subjected to explosion load (Geffroy et al., 2011).

5. Numerical modeling in estimating damage and safety Calculation using a numerical approach is used for performance criteria of structure and material subjected to explosion accidents. Taking nuclear power plants as the main subject, vents, walls, and openings of the safety-related buildings, considered in research. Time dependence of overpressure criterion is discussed by Ismaila et al. (2019) for different locations. It is concluded that the impacts at X2 and X3 may not have a hostile influence as the generated peak explosion pressure is 0.05 bar, which could only lead to minor structural damage. Interesting results are noted that the explosion case at X1 also presents more enormous challenges to the operational safety of the plant. For butane/air blast, a maximum impulse loading of 0.01521 bars at 1.93 s is found to impact the walls of the control room building in the X1 direction. The verification of structural modeling for explosion analysis is possibly conducted by controlling element numbers on geometrical models. As presented in Fig. 8, structural integrity starts to stabilize with approximately 5000 element numbers being implemented to the target structure of the explosion. In the calculation of subsurface blast, pipeline PL72 experienced larger longitudinal strain compared to PL57.6 for different internal pressure and TNT amount. The structural integrity of a ship is capable of being assessed by its longitudinal strength after interacting with external forces, such as wave, collision, grounding, and also explosion. Previous work of Zhang et al. (2011) in this subject concludes that the sagging break occurred to the destroyer at the midship due to bubble load from explosion based on vertical displacement distribution curves. Analysis using the finite element method (FEM) is conducted in assessing the dynamic response of operating metro tunnels due to ground explosion. Results in Fig. 9 indicate that the wave propagation in the soil at different times, in which the pressure waves expand the form of hemispherical pattern.