A novel prefabricated wall panel structure for substations was developed by integrating fiber cement board, aluminum honeycomb plate, and aluminum alloy plate. The dynamic response characteristics of the structure under explosive loads were investigated through experimental studies. The effects of overpressure loads at different explosive mass and loading distances were examined, and the impact of varying honeycomb cell sizes on structural deformation failure mode, back face deflection and strain, core compression, and fiber cement board crack distribution was analyzed. The results indicate that within a confined space, the time characteristics of explosion overpressure are similar to those in an unconfined space. The peak overpressure measured independently at the center is between 2.4 and 10.0 times that measured directly at the edge. The positive pressure duration measured independently at the center is between 0.44 and 0.71 times that measured directly at the edge. The predominant deformation mode of the structure involves front panel depression and rear panel bulging. Horizontal cracks in the front face of the fiber cement board are predominantly located near its long side boundary, while cracks in the back face are mainly distributed near its center and diagonal areas. Compared with structures featuring smaller honeycomb cell sizes, those with larger honeycomb cell sizes exhibit greater residual deflection on their back faces and longer total crack lengths in their fiber cement boards.

The honeycomb core layer is light and has the advantage of high specific stiffness, specific strength and specific energy absorption. A novel prefabricated wall panel structure for substations was designed by combining fiber-reinforced concrete panels, honeycomb core layers, and aluminum alloy panels. The dynamic response of the structure under the blast load was investigated, as well as the effect of the explosive mass and the size of the honeycomb core. In this paper, a finite element model was established and compared with the experimental results, which was found to be in good agreement with each other, thus validating the model. On this basis, the effects of explosive mass and honeycomb core layer on the structural deformation failure mode, midpoint deflection of back panel and energy absorption were investigated. It is shown that the deformation pattern of the structure is mainly concave at the front and convex at the back, and the honeycomb core layer is compressed, resulting in the whole deformation. Then the fiber cement of the front panel is separated with the honeycomb core layer, and the fiber-reinforced concrete panels of the back panel have failure at the center and diagonal, and the crack expandes, and the compression of the core layer increases. It was found that for the same amount of explosion, the center deflection of the back panel of the honeycomb structure with small size was reduced by 18.5%, 17.1%, and 18.1% compared to the honeycomb structure with large size. Meanwhile, the energy absorption of the honeycomb structure with small size was increased by 7.8%, 6.7%, and 2.2% respectively compared with that of the honeycomb structure with large size. Thus, the honeycomb structure with small size has better impact resistance. Under blast load, the fiber-reinforced concrete panels on the front panel absorbs the most energy, accounting for more than 50%, followed by the honeycomb core layer, accounting for about 45%, and the back panel fiber-reinforced concrete panels absorbs less energy, and the energy absorption is within 5%.