Modeling And Simulation Of Honeycomb Steel Sandwich Panels Under Blast Loading (original) (raw)
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Modeling, Simulation and Optimization of Steel Sandwich Panels under Blast Loading
American Journal of Engineering and Applied Sciences
Honeycomb sandwich panels are commonly preferred in structural engineering as a design element meant to protect against blast loading, and this owes primarily to the fact that they are light in weight (due to the voids present) whilst carrying high energy absorption capacities. A widespread surge in acts of terrorism, and the resultant threat posed to structures, presents structural engineers with unique challenges pertaining to the design of blast-resistant structures that are both safe and reliable. Researchers worldwide have thus taken to closely studying the effects of sudden loads effected by detonative forces on certain elements and design concepts. To this end, an emergent design concept with proven efficacy is the honeycomb sandwich panel. Due to the practical difficulties associated with the study of explosive materials and replicating blast loads, softwarebased modeling and simulation may be favorable as a functional and convenient alternative. To this end, this work uses the finite element package ABAQUS ® to study the behavior of hexagonal and squared honeycomb steel sandwich panels under the explosive effects of different amounts of trinitrotoluene (TNT). The results of finite element modeling of a specific honeycomb configuration are initially validated by comparing them with the experimental results from literature. Several configurations including different geometrical properties of the honeycomb wall are then investigated and the results are compared. Consequently, an optimization study is conducted with an objective to reduce the plastic strain of the back plate while the wall cell thickness is taken as a variable. Finally, the effectiveness of the core shape and wall thickness is discussed and conclusions are made.
Optimum Design for Sandwich Panels with Metallic Hexagonal Honeycomb Core Subjected to Blast Loads
The International Conference on Civil and Architecture Engineering (Print), 2008
In the last decade, design and optimization of structures subjected to blast loads got the attention of many researchers. The great threaten of terrorizing activates; in addition to instability in different areas of the world drive these researches. Sandwich panels give an optimum and proven tools to handle problems related to design and analysis of such structures. The present work focuses on increasing the blast resistance of steel sandwich panels. These panels can be applied on defense works, homeland security, banks and civilian industries intended to minimize the effects of accidental explosions. Sandwich constructions with metallic hexagonal honeycomb core are utilized in this research due to its high specific strength and stiffness with minimum weight. Minimizing the weight of the metallic hexagonal honeycomb core is regarded as the objective function of the optimization process that was tested under blast loads resulted from detonating 100 kg of TNT at 5-m stand-off distance. The strength and stiffness of honeycomb core panels were evaluated based on constraint condition of strength and deformation. A response surface analysis was performed on the parameters affecting the allowable global displacement by simplifying the explosion pattern and developing a response limits adapting TM5 requirements [1]. F.E. technique was utilized to handle the numerical configuration of the studied cases. ANSYS code [2] proved the environment for processing the analysis and optimization. The proposed approach suggested to control the parametric optimization analysis succeeded to provide an optimum configuration for the metallic hexagonal honeycomb core structure under blasting condition.
Materials & Design, 2010
This paper reports on an investigation into the behaviour of circular sandwich panels with aluminium honeycomb cores subjected to air blast loading. Explosive tests were performed on sandwich panels consisting of mild steel face plates and aluminium honeycomb cores. The loading was generated by detonating plastic explosives at a predetermined stand-off distance. Core height and face plate thickness were varied and the results are compared with previous experiments. It was observed that the panels exhibited permanent face plate deflection and tearing, and the honeycomb core exhibited crushing and densification. It was found that increasing the core thickness delayed the onset of core densification and decreased back plate deflection. Increasing the plate thickness was also found to decrease back plate deflection, although the panels then had a substantially higher overall mass.
This paper reports on an investigation into the behaviour of circular sandwich panels with aluminium honeycomb cores subjected to air blast loading. Explosive tests were performed on sandwich panels consisting of mild steel face plates and aluminium honeycomb cores. The loading was generated by detonating plastic explosives at a pre-determined stand-off distance. Core height and face plate thickness were varied and the results are compared with previous experiments. It was observed that the panels exhibited permanent face plate deflection and tearing, and the honeycomb core exhibited crushing and densification. It was found that increasing the core thickness delayed the onset of core densification and decreased back plate deflection. Increasing the plate thickness was also found to decrease back plate deflection, although the panels then had a substantially higher overall mass.
Energy Absorbing Sandwich Structures Under Blast Loading
A recent experimental study at the Army Research Laboratories shows that flat panels with various foam or honeycomb faceplates transferred more energy to a structure under blast loading relative to a structure without an energy absorbing faceplate. Ideally, the foam or honeycomb material should transfer less energy to the structure since it absorbs energy while it deforms plastically. Non-uniform deformation of the energy absorbing material may lead to increased pressure on the panel, causing kinetic energy transfer to the plate. One objective of this work is to simulate the non-uniform response of the honeycomb panel subject to blast loading. Most of the work involves an investigation into the optimum design of the honeycomb structure for energy absorption during blast loading. In this paper, only a square-celled honeycomb structure is studied. Variables under investigation for this paper are the core and face sheet thicknesses of the honeycomb sandwich structure. Results of a DOE ...
Behaviour of sandwich panels subject to intense air blasts – Part 2: Numerical simulation
Composite Structures, 2009
Finite element simulation is employed to analyse the behaviour of clamped sandwich panels comprising equal thicknesses mild steel plates sandwiching an aluminium honeycomb core when subject to blast loadings. Pressure-time histories representative of blast loadings are applied to the front plate of the sandwich panel. The FE model is verified using the experimental test results for uniform and localised blast loading in the presence of a honeycomb core and with only an air gap between the sandwich plates. It is observed that for the particular core material, the load transfer to the back plate of the panel depends on the load intensity, core thickness and flexibility of the sandwich panels.
Behaviour of sandwich panels subjected to intense air blast – Part 1: Experiments
Composite Structures, 2009
Tests that investigate the inelastic response of blast-loaded sandwich structures, comprising mild steel plates and aluminium alloy honeycomb cores, are reported. The ''uniform" loading was generated by detonating a disc of explosive and directing the blast through a tube towards the target. Localised blast loading was generated by detonating discs of explosive in very close proximity to the test structure. The sandwich panels responded in a more efficient manner to the uniformly distributed loading, and hence the majority of the paper is concentrated on uniform loading response. The honeycomb sandwich results are compared to test results on structures with air as the core. The failure modes and interaction between the components are discussed. Three phases of interaction are identified for each sandwich structure, based upon deformation, contact, crushing and tearing responses of the sandwich components. The compromise between load transfer through the core and improved energy absorption is discussed.
Strain Rate Analysis of Efficient Honeycomb Sandwich Panels under Blast Load
Research Square (Research Square), 2023
Honeycomb sandwich panels are investigated for a broad range of areas as protective structures that can withstand blast loading. The advantage of these panels is that they are light in weight when compared to solid metal plates due to the hollow core and have high energy absorption capabilities. Due to their high bending stiffness, honeycomb sandwich panels have found applications in aerospace, automotive, marine, defense, and railway industries. In order to analyze the effect of blast loading on sandwich panels the experiments that need to be conducted are costly as well as time-consuming. Also, while conducting experiments with explosives, human safety is a major concern. Taking the aforementioned parameters into consideration, modeling and simulation of honeycomb sandwich panels is the better alternative. ABAQUS software has been used in this paper to study the behavior of metallic honeycomb sandwich panels (MHSP) with squared, hexagonal, and circular cores when subjected to blast loads of different kilograms of trinitrotoluene (TNT). The obtained simulation results show that circular core has higher blast resistance as compared to hexagonal and square cores. With the aim of optimizing blast protection characteristics of the sandwich model, effect of gel-lling and addition of Aluminium foamto hollow honeycomb core of the sandwich panelswas investigated.The face plate de ection and energy absorption capacity were found to have improved after these additions. Mass evaluation pertaining to reduction in plate de ection versus increase in weight of the sandwich panel after addition of gel and foam was also performed. The in uence of strain rate on the de ection of blast-loaded sandwich panels was also studied. It was found that higher strain rates gave favourable results i.e., lower deformation values. Lastly, energy absorption study of all the various con gurations of the sandwich panel was performed.
Failure analysis on octagonal honeycomb sandwich panel under air blast loading
Materials Today: Proceedings, 2020
In recent days ''honeycomb sandwich panels" are widely used against high intensity blast load due to the high energy absorption capability of the honeycomb structure. In this research paper determined the structural behavior of the honeycomb sandwich panel is subjected to the blast loading. Different honeycomb cores like square and octagonal structures are used to determine the minimum deflections for the top and back plates and also maximum energy absorption for the sandwich panel. The honeycomb sandwich panel is consists of the two solid plates (top plate and bottom plate) and one honeycomb core shell type structure. The blast is applied at a constant standoff distance from top plate of the sandwich panel. The sandwich panel is subjected to the blast load using the different masses of explosive charges such as 1 kg, 2 kg and 3 kg of the Trinitrotoluene (TNT) for the explosion in the air, at a constant standoff point distance from the top plate of sandwich panel. The finite element model is performed by ABAQUS software to determine the dynamic response for the sandwich panel. The quarter part of the honeycomb sandwich structure was modeled and imposed symmetry boundary conditions for the honeycomb sandwich panel to minimize the memory storage of the system and reduced the computation time of the analysis. The top and back face deflections of the square honeycomb sandwich panel have been validated with experimental results available in the literature in square honeycomb sandwich panel. There is a possibility of under estimation of the front face and back face deflections for the sandwich panel, if the honey comb structures are not considered an octagonal sandwich panels for different blast loads.
Response of flexible sandwich-type panels to blast loading
This paper reports on experimental and numerical investigations into the response of flexible sandwich-type panels when subjected to blast loading. The response of sandwich-type panels with steel plates and polystyrene cores are compared to panels with steel face plates and aluminium honeycomb cores. Panels are loaded by detonating plastic explosive discs in close proximity to the front face of the panel. The numerical model is used to explain the stress attenuation and enhancement of the panels with different cores when subjected to blast induced dynamic loading. The permanent deflection of the back plate is determined by the velocity attenuation properties (and hence the transmitted stress pulse) of the core. Core efficiency in terms of energy absorption is an important factor for thicker cores. For panels of comparable mass, those with aluminium honeycomb cores perform ''better" than those with polystyrene cores.