In this study, we focused on the large inelastic behavior of a sandwich panel made of two solid plates as a stiffener and a honeycomb core shell subjected to blast load. The loading scheme was carried out using an explosive charge bullet mounted at a standoff distance of 100 mm with three mass variations of trinitrotoluene: 1, 2, and 3 kg TNT. The numerical simulations performed using ABAQUS/CAE were validated with the experimental results of a previous study. The geometrical effects of the sandwich panel on intact and damaged models were also numerically investigated. The panel was designed using a square and hexagonal honeycomb core. The effect of honeycomb core height was also observed by modeling the core using three height variations: 31, 51, and 71 mm. The results showed that the hexagonal core was more resistant to blast loads than the square design. The core height parameter determines the energy absorption based on these results. The structural strength is also affected by the damage. The findings of this study can be used to improve structural designs that utilize sandwich panels to withstand blast loads. Doi: 10.28991/CEJ-2022-08-05-014 Full Text: PDF

In this paper, the buckling analysis on simply supported rectangular plates and stiffened panels is carried out. Three different plate thicknesses were proposed (i.e., 3 mm, 4 mm, and 5 mm). The thickness of the longitudinal stringers and sub-stiffeners were also varied. The material that was used was marine grade steel. The load versus the displacement curve and the total energy were measured. The buckling analysis results were examined via finite element (FE) computation. To ensure that the results of the methodology for the finite element were reliable, the benchmark buckling analysis of the experimental test was reconstructed. For the selection of mesh size, the element to thickness ratio method (ELT) was used. The results revealed that the thickness of the plate increases the strength of the stiffened panel. The plate thickness of 5 mm increased by 65.7% and 20.61% compared with the 3 mm and 4 mm plate thicknesses. A change in the thickness of the sub-stiffeners does not significantly change the strength of the stiffened panels. Material S355JR-EN10210 produced a higher ultimate panel collapse load compared with S235JR-EN10025 (A) and S235JR-EN10025 (B).

Cylindrical shell structures are ubiquitous and essential supporting structures in various engineering applications. The aim of this research work is to provide a comprehensive overview of the behavior of cylindrical shell structures under different loading conditions, including external pressure, axial compression, and bending moment. The study found that the behavior of cylindrical shells was affected by their geometry, including diameter, length, thickness, and imperfections. These factors should be carefully considered in the design and analysis of cylindrical shells. Additionally, stiffeners and sandwich structures can be applied to improve the structural performance of cylindrical shells under different loading conditions. The work also highlighted the latest research trends in the field, such as the use of advanced materials, and numerical simulations to improve the understanding and design of cylindrical shell structures. Overall, this study has provided a valuable resource for engineers and researchers working on cylindrical shell structures, helping them to design and analyze the cylindrical shell structures more efficiently and effectively.

Indonesia is the largest archipelagic country and has the potential to become the world’s maritime axis. Two-thirds of Indonesia’s territory is ocean, with a total coastline of 54,716 km. Therefore, Indonesia must have solid systems and tools to overcome the various threats in the maritime sector. One of the technologies that can be developed to protect Indonesia’s naval territory is fast patrol boats. Indonesia requires efficient patrol boats that can optimally monitor the large Indonesian sea area and various potential threats in the maritime sector. Thus, research on the hydrodynamic criteria for the hull design of patrol boats is fundamental. In this study, we aimed to evaluate the design method based on hydrodynamic characteristics to obtain the primary dimensions and shape of the ship’s hull. We designed and analysed 11 ship models in terms of the following criteria: the resistance, stability, and seakeeping performance. The 11 models included five reference models of patrol boats with varying dimensions and block coefficients between 0.42 and 0.53, three ship models with the regression method with the exact dimensions and block coefficients between 0.45 and 0.46, and three ship models with the scale method with the exact measurements and block coefficients between 0.43 and 0.45. According to the analysis results, the regression method had better total hydrodynamic criteria and greater similarity to the reference vessel. With a shorter processing time, the regression method was more efficient than the scaling method and reference ship.

Explosion load studies are an essential part of shield engineering design. This is especially true for explosion-proof plates, which are used in order to reduce the impact of explosions, which have the potential to cause substantial damage to structural elements. The purpose of this study is to detail the explosion phenomenon and the response of sandwich panel structures under explosive loading. The finite element method (FEM) is used to model the dynamic structural response to explosions. Explicit finite element modeling and analysis are performed using ABAQUS CAE software. An air explosion simulation code is used to determine the blast load on the lower skin plate of a test panel on a typical armored personnel vehicle. Structural analysis is carried out with respect to displacement, von-Mises stress, and internal kinetic energy. Three variations of explosive loads are considered in the simulation in order to better compare the responses of the structures. Three different design variants and materials are considered, including honeycomb, stiffener, and corrugated geometric models and mild steel, medium carbon steel, and alloy steel materials. The results provided by this study pave the way toward the development of guidelines for the design of lightweight structural reinforcement elements.