It is a challenging task to advance the excellent strength and structural performance of sandwich structures, while continuing to reduce the weight and cost parameters. Thousands of researchers hav...

A review of the recent trends on core structures and impact response of sandwich panels

Precise bending stress analysis of corrugated-core, honeycomb-core and X-core sandwich panels

In this study, novel honeycomb structures with twisted feature were designed and manufactured by laser powder bed fusion (LPBF). The manufacturability, microstructure evolution of LPBFed honeycomb components with twisted feature were studied. The influence of twist angle on the compressive behavior of components was experimentally investigated and the underlying mechanism was revealed using FE simulation. Results revealed that the material relative density of LPBFed components was reduced with the increase of twist angle, caused by the enlarging overhanging area. Different cooling rate of melt pool at different parts along the building direction resulted in different microstructures. The twist angle significantly affected the compressive behaviors of honeycomb structures. When the cell number along each side was 3, the honeycomb structure with 30° twist angle exhibited the most uniform stress distribution under compression, leading to the highest specific compressive strength and energy absorption ability. The influence of cell number and wall thickness on compressive properties of honeycomb structures with 30° twist angle were investigated through finite element simulation, and results revealed that the structure with 0.75 mm wall thickness and 3 unit cells along each side showed the highest specific energy absorption ability.

Laser powder bed fusion of bio-inspired honeycomb structures: Effect of twist angle on compressive behaviors

A numerical study for a functional design of honeycomb meta-materials targeting flexible shear properties (about 6.5MPa effective shear modulus and 15% maximum effective shear strain) is conducted with two material selections — polycarbonate (PC) and mild-steel (MS), and five honeycomb configurations. Cell wall thicknesses are found for each material to reach the target shear modulus for available cell heights with five honeycomb configurations. PC honeycomb structures can be tailored with 0.4 to 1.3mm cell wall thicknesses to attain the 6.5MPa shear modulus. MS honeycombs can be built with 0.2mm or lower wall thicknesses to reach the target shear modulus. Sensitivity of wall thickness on effective properties may be a hurdle to overcome when designing metallic honeycombs. The sensitivity appears to be more significant with an increased number of unit cells in the vertical direction. PC auxetic honeycombs having 0.4 to 1.9 mm cell wall thicknesses show 15% maximum effective shear strain without local cell damage. Auxetic honeycombs having negative Poisson’s ratio show lower effective shear moduli and higher maximum effective shear strains than the regular counterparts, implying that auxetic honeycombs are candidate geometries for a shear flexure design.Copyright © 2009 by ASME

Design of honeycomb meta-materials for high shear flexure

The effect of node bond adhesive fillet on uniaxial in-plane responses of hexagonal honeycomb core

Static analysis of sandwich panels with a square honeycomb core is performed using the finite element approach applied to the plate theories. The constitutive behavior of an equivalent continuum to the core is obtained using the strain energy approach. The displacement field of the sandwich panel modeled using the equivalent continuum is then compared with results obtained from a highly detailed finite element method created in ABAQUS. The comparison shows the results of the higher-order shear deformation theory in error of 7.6% compared with the detailed model results. An equivalent single layer finite element method for the sandwich panel was then created in ABAQUS and the displacement results of this equivalent single layer model are compared with those obtained from the detailed finite element method. This comparison reveals an error of 6.1% in the results between the two models. A comparison between the equivalent single layer model and the highly detailed model is presented for different core relative densities at two locations of the sandwich panel. A detailed finite element method analysis of the unit cell of the square honeycomb was next performed using ABAQUS and the flexibility approach. Comparison between the equivalent strain energy approach and flexibility approach applied to detailed ABAQUS models of the unit cell proved the equivalent strain energy approach to be efficient.

Static Analysis of Sandwich Panels with Square Honeycomb Core

An investigation was performed to study the effect of uncertainty in applied loads, helix angles, and failure stresses on the probability of failure of composite cylinders. Also, the effect of the factor of safety on the probability of failure of the cylinder was studied. The probability of failure for a composite cylinder subject to axisymmetric loading was obtained using the First Order Reliability method (FORM). The failure of the cylinder was studied based on first ply failure. Ply failure was predicted using the non-smooth Hashin criterion. Hashin criterion is based on writing a different interaction equation for separate failure modes. Four failure modes are considered associated with matrix or fiber failure, in either tension or compression. The accuracy of FORM as applied to this problem was verified by comparing the FORM results to those obtained by Monte-Carlo Simulation method with importance sampling. i x µ = mean values of the design parameters i x

Probability of Failure of Composite Cylinders Subjected to Axisymmetric Loading

*† ‡ § ** tatic analysis of sandwich panels with square honeycomb core is presented. The displacement field of the sandwich panel is obtained. The analysis of the panel is done using the finite element approach applied to the Classical Laminated Plate theory (CLPT), the First Order Shear Deformation theory (FSDT) and the Higher Order Shear Deformation Theory (HSDT). The constitutive behavior of a continuum equivalent to the core is obtained using Hohe’s approach which is a homogenization approach based on the strain energy equivalence between a body containing cellular structure and a continuum body. The results of the displacement field of the sandwich panel are then compared to results obtained from a highly detailed FEM created in ABAQUS ® in which the cell walls of the honeycomb core are modeled as shell elements, this comparison shows that the displacement results of the HSDT are in error of 7.6% when compared to the detailed ABAQUS ® model. An alternative procedure for calculating the constitutive behavior of the continuum equivalent to the square honeycomb was pursued here by creating detailed FEM of the unit cell of the square honeycomb using ABAQUS ® to detailed representative models and applying static loads to these models then obtaining the properties by means of the flexibility approach. Comparison between the equivalent strain energy approach and flexibility approach applied to detailed ABAQUS models of the unit cell of the square honeycomb proved the equivalent strain energy approach to be efficient. Simple formulas for calculating the different Elastic properties of equivalent continuum to the square honeycomb are introduced. S

On the Static Analysis of Sandwich Panels with Square Honeycomb Core

A summary of the existing models available for predicting the mechanical properties of a continuum equivalent to the honeycomb cellular structure is presented. Assessment of the accuracy of these models, using an extensive set of cell sizes and core densities, in providing the correct homogenized properties and capturing the cell size effect is performed. The assessment of the models already existing in the literature is performed by comparing the constitutive properties obtained using these models to those obtained using detailed finite element models of the honeycomb representative unit cells. Five cell sizes and twenty core densities were assessed. Three of the models assessed are considered to be complete models as they provide empirical formulas to calculate all components of the constitutive behavior while two are considered to be partial models as they focus on either the in-plane or out-of-plane properties of the honeycomb cellular core. The assessment results show only one of the five models providing reasonable results compared to those of the detailed finite element models.

Assessment of Existing Models for Honeycomb Homogenized Properties

omparison among the equivalent-continuum (homogeneous) constitutive law for Hexagonal, square and triangular cores to be used in sandwich panels is presented. The cellular core homogeneous properties are calculated using detailed finite element models of representative unit cell for each core shape. A strain energy based homogenization scheme that was first presented by Hohe and is based on the concept that for every cellular material, there exists a homogeneous material that is of the same shape and behaves identically to the cellular structure when it is subject to the same loading and boundary conditions is also be used to calculate the constitutive law for the same core shapes and the same core densities. A detailed comparison between the homogenized constitutive law obtained using the detailed finite element models and that obtained using Hohe’s approach is presented herein. The strain energy based homogenization scheme was previously verified by Soliman et. al. [1] for a non-corrugated square shape core. In this paper, the hexagonal and square core shapes are made of corrugated Aluminum 5056 sheets. The variation of the mechanical behavior of the homogeneous structure equivalent to the cellular core with respect to the relative density and cell size of the cellular core is analyzed and equations for direct calculation of the constitutive behavior of the three types of cellular core is presented. Additionally, different finite element modeling techniques of the cellular cores within a 10”× 10” panel with simply supported boundary condition is also presented. The finite element modeling techniques presented are: a) detailed modeling of the cellular core within a sandwich panel, b) 2D modeling of the equivalent continuum within a sandwich panel using the MAT8 NASTRAN ® card to represent the core homogenized material , and c) 3D modeling of the equivalent continuum within a sandwich panel using the MAT9 NASTRAN ® card to represent the core homogenized material. The modeling techniques will be compared in terms of the displacement field of sandwich panels consisting of the different types of cellular core and subject to uniform pressure.

Comparison Between Different Cellular Cores and Finite Element Modeling Techniques

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Hazem E. Soliman

Author Tools

Chat about Author