PSI - Issue 60

Prince Jeya Lal Lazar et al. / Procedia Structural Integrity 60 (2024) 185–194 Author name / Structural Integrity Procedia 00 (2019) 000–000

191

7

subjected to blast loads generated by 2 and 3 kg TNT. When the core thickness is constant, an increase in explosive charge mass can cause the core to crush or yield more easily. The higher pressure and impulse can induce larger deformations in the core material, potentially leading to its failure. This is particularly true if the core material is less resilient or has lower energy absorption capabilities. If the core crushing progresses to a certain extent, it can lead to structural failure, compromising the integrity of the sandwich panel. This can have serious implications for the overall system's performance and safety. The effects of varying the standoff distance on the front face deflection are presented in Fig 6. The stand-off distance refers to the distance between the explosive charge and the front face of the honeycomb panel. It is a key parameter that significantly affects the structural response of the sandwich panel to the explosion. Increasing the stand off distance tends to reduce the severity of the blast impact on the front face. Panels subjected to explosions at longer stand-off distances experience lower peak pressures and impulse loads, leading to reduced front-face deformation and core crushing. A greater stand-off distance provides more time for the blast wave to disperse and lose energy, which results in less direct impact on the panel. In this work, a 25% and 50% increase in standoff distances leads to a 35.93% and 72.45% decrement in front face midpoint deflection for a constant TNT mass of 1 kg and a core thickness of 0.76 mm.

(a)

(d)

(b)

(e)

(f)

(c)

Fig. 6 Front face midpoint deflections in panels with 0.76 mm core thickness exposed to a blast load equivalent to 1 kg TNT for varying standoff distances (a, d) 100 mm (b, e) 125 mm (c, f) 150 mm [a, b, c – Surface explosion, d, e, f – Underwater explosion]

The velocity of the incident shock wave on the front face of the sandwich panel is comparable to the impulse load of the blast. A higher shock wave velocity possesses a potential for greater damage. The effects of varying the core thickness on the front face deflection are presented in Fig. 7 and Fig. 8. The thickness of the honeycomb core in