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An innovative multi-layer composite explosion containment vessel (CECV) utilizing a sliding steel plate-aluminum honeycomb-fiber cloth sandwich is put forward to improve the anti-explosion capacity of a conventional single-layer explosion containment vessel (SECV). Firstly, a series of experiments and finite element (FE) simulations of internal explosions are implemented to understand the basic anti-explosion characteristics of a SECV and the rationality of the computational models and methods is verified by the comparison between the experimental results and simulation results. Based on this, the CECV is designed in detail and a variety of FE simulations are carried out to investigate effects of the sandwich structure, the explosive quantity and the laying mode of the fiber cloth on anti-explosion performance and dynamic response of the CECV under internal explosions. Simulation results indicate that the end cover is the critical position for both the SECV and CECV. The maximum pressure of the explosion shock wave and the maximum strain of the CECV can be extremely declined compared to those of the SECV. As a result, the explosive quantity the CECV can sustain is up to 20 times of that the SECV can sustain. Besides, as the explosive quantity increases, the internal pressure of the CECV keeps growing and the plastic deformation and failure of the sandwich structure become more and more severe, yielding plastic strain of the CECV in addition to elastic strain. The results also reveal that the laying angles of the fiber cloth's five layers have an impact on the anti-explosion performance of the CECV. For example, the CECV with fiber cloth layered in 0(/45(/90(/45(/0( mode has the optimal anti-capacity, compared to 0(/0(/0(/0(/ 0( and 0(/30(/60(/30(/0( modes. Overall, owing to remarkable anti-explosion capacity, this CECV can be regarded as a promising candidate for explosion resistance. [ABSTRACT FROM AUTHOR]

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The face–core debonding of sandwich structures under bending will affect the overall load-bearing capacity. Fiber metal laminate (FML) sandwich composite structures with 3D woven hollow integrated core (3D core) were prepared by vacuum resin infusion method and thermal molding process. The flexural behavior of the structures was experimentally studied by a three-point bending test and investigated by evaluation of specific flexural strength, flexural rigidity, and ductility. Numerical simulation finite element models of structures with different cores under three-point bending were calculated by ABAQUS/Explicit. Results showed that plastic rotation of the "8"-shaped fibers in the 3D core was the main reason for the failure modes of asymmetric densification. FML as the faceplate of the 3D core can significantly improve its flexural strength, rigidity, and ductility. [ABSTRACT FROM AUTHOR]

The honeycomb sandwich structure has been widely used in the field of aerospace owing to extremely high specific strength and specific rigidity. However, the honeycomb core has anisotropic mechanical characteristics and in-plane weak rigidity, which brings new challenges to the cutting process. In this paper, a three-way equivalent heat conduction model including heat conduction and heat convection in the cutting process was established based on the structural characteristics of the honeycomb core. As for the milling cutter combined with the crushing blade and circular blade specified for aluminum honeycomb core, the moving surface heat source of the crushing blade and the moving line heat source of the circular blade during the milling process were proposed. A prediction model of temperature distribution in the milling of aluminum honeycomb core based on the two heat moving sources was established and verified by the milling experiments. Finally, the temperature distribution law and heat affected area of the honeycomb core during the milling process were studied. It was found that the milling temperature of the honeycomb core maintained a high temperature in the contact area, but fell sharply outside the contact area. Moreover, the heat affected area of the milling heat does not exceed three honeycomb cores. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study of the compressive response of hexagonal honeycomb core from the initial elastic regime to a fully crushed state. To understand the crushing mechanism, aluminum honeycomb core was compressed quasi-statically between rigid platens under displacement control. Honeycomb test specimens made of aluminum alloy with different configurations such as cell size, cell number, core density, and specimen size have been tested. During the crushing, the cells buckle elastically and collapse at a higher stress due to inelastic action, after the cells crush by progressive formation of folds on cell walls. The response densifies when folds consume the whole panel height. The peak load recorded during tests corresponded to the buckling of honeycomb cells. The different specimens showed similar load/displacement curves, and the differences observed were only due to the influence of the core density, number of cells, and specimens size on mechanical behavior of hexagonal honeycomb core which has a very important role in the energy absorption capacity. In addition, this study allowed us to build a database of experimental tests for various configurations and allowed us to know the precise energy absorption capacity. [ABSTRACT FROM AUTHOR]

This paper presents a new developed ultra-lightweight composite sandwich with very good mechanical properties suitable for aerospace and defense applications. The 13.8 mm thick structure has a 3003 aluminum honeycomb core with 5.2 mm cell size and two opposite skins made of woven glass fabric reinforced epoxy resin laminates. Very good stiffness and mechanical work have been obtained during three-point bend tests. Samples have been subjected to load at break and up to 50 mm deflection. More compact values of mechanical properties have been obtained at break than at 50 mm deflection. [ABSTRACT FROM AUTHOR]

Aluminum honeycomb core is one of the most sought after material for the sandwich panel for light weight applications. While the aluminum face sheet is isotropic, the honeycomb core assumes orthotropic characteristics due to its configuration and strenuous load transfer paths. It is now well established that stiffness, dynamic, and low velocity impact response of the honeycomb core sandwich panel are critically dependent on the elastic constants of the core. An attempt is made to determine the elastic constants of orthotropic core through finite element approach simulating the load transfer and fixity boundary conditions likely to be prevalent in the unit cell of the honeycomb core. The cell wall thickness and the cell shape dictated by plastic bending limitations have also been simulated to determine their influence on the elastic constants. Further, the cell wall thickness and the bend radius have been varied and their influence on orthotropic elastic constants has been determined. The results of the study have been compared with analytical solutions proposed by researchers. The finite element procedure evolved is a simple, efficient, and quick solution methodology to accurately predict elastic constants of honeycomb core depicting the exact cell size and shape. [ABSTRACT FROM AUTHOR]