scholarly journals Bioinspired Honeycomb Core Design: An Experimental Study of the Role of Corner Radius, Coping and Interface

Biomimetics ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 59
Author(s):  
Derek Goss ◽  
Yash Mistry ◽  
Sridhar Niverty ◽  
Cameron Noe ◽  
Bharath Santhanam ◽  
...  
Keyword(s):  
Flexural Modulus ◽  
Honeycomb Core ◽  
Design Features ◽  
Corner Radius ◽  
Out Of Plane ◽  
Cell Arrays ◽  
Plane Compression ◽  
Honeycomb Cores ◽  
Performance Gains

The honeybee’s comb has inspired the design of engineering honeycomb core that primarily abstract the hexagonal cell shape and exploit its mass minimizing properties to construct lightweight panels. This work explored three additional design features that are part of natural honeybee comb but have not been as well studied as design features of interest in honeycomb design: the radius at the corner of each cell, the coping at the top of the cell walls, and the interface between cell arrays. These features were first characterized in natural honeycomb using optical and X-ray techniques and then incorporated into honeycomb core design and fabricated using an additive manufacturing process. The honeycomb cores were then tested in out-of-plane compression and bending, and since all three design features added mass to the overall structure, all metrics of interest were examined per unit mass to assess performance gains despite these additions. The study concluded that the presence of an interface increases specific flexural modulus in bending, with no significant benefit in out-of-plane compression; coping radius positively impacts specific flexural strength, however, the corner radius has no significant effect in bending and actually is slightly detrimental for out-of-plane compression testing.

Interfacial Phenomena in Brazing of a Stainless Steel Face Sheet to a Honeycomb Core

2009 ◽  
Vol 83-86 ◽  
pp. 1236-1242 ◽  
Author(s):  
S. Mehrizi ◽  
A.M. Hadian ◽  
A. Hadian ◽  
A. Vosughi
Keyword(s):  
Stainless Steel ◽  
Crucial Role ◽  
Heat Treating ◽  
Holding Time ◽  
Interfacial Phenomena ◽  
Honeycomb Core ◽  
Wetting Behavior ◽  
Vacuum Brazing ◽  
Honeycomb Cores

One of the difficulties in manufacturing of sandwich honeycomb structures is the proper joining of honeycomb cores to face sheets. In this investigation, vacuum brazing process using BNi-2 brazing alloy was applied for these types of joints. Brazing cycles were performed at temperatures ranging from 1020 to 1050oC under different holding times ranging from 5 to 20 min. Three different zones were observed in the solidified braze layer. The width of each zone was altered by brazing cycle. The results showed the crucial role of boron element in the brazing alloy in wetting behavior and final products after brazing. The optimum brazing cycle was found to be 1020oC and 5 min holding time followed by heat treating the brazed samples at 600oC for 6 hrs.

Out-of-Plane Mechanical Property Test on Titanium Honeycomb Cores

2013 ◽  
Vol 718-720 ◽  
pp. 1018-1023
Author(s):  
Zong Hong Xie ◽  
Xiao Yu Liu ◽  
Xi Shan Yue ◽  
Qun Yan ◽  
Jun Feng Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Test ◽  
Solid Model ◽  
Honeycomb Core ◽  
Plane Shear ◽  
Cellular Solid ◽  
Homogeneity Assumption ◽  
Out Of Plane ◽  
Honeycomb Cores ◽  
Orthotropic Behavior

As a typical cellular solid, the honeycomb core shows an orthotropic behavior in its mechanical properties. Engineering analysis often adopts a homogeneity assumption that honeycomb core is equivalent to an anisotropic continuum. Currently available cellular solid model cannot predict the physical properties of titanium honeycomb core with acceptable accuracy. Therefore, mechanical test must be carried out to obtain the mechanical properties of metallic honeycomb structures. This paper introduces the work on flatwise compression test and out-of-plane shear test on titanium honeycomb core structures in accordance to ASTM C 365-03and ASTM C 273-00. The out-of-plane stiffness and strength for titanium honeycomb cores with incircle diameter of 4.8mm and wall thickness of 0.05mm were obtained.

Experimental and Finite Element Based Investigations of In-Plane and Out-of-Plane Properties of Aluminum Honeycomb

2013 ◽  
Vol 275-277 ◽  
pp. 111-116 ◽  
Author(s):  
Muhammad Kashif Khan ◽  
Qing Yuan Wang
Keyword(s):  
Finite Element ◽  
Sample Size ◽  
Cell Size ◽  
Mechanical Response ◽  
Honeycomb Core ◽  
Element Analysis ◽  
Out Of Plane ◽  
Aluminum Honeycomb ◽  
Plane Direction ◽  
Honeycomb Cores

Experimental and Finite Element analysis was used for the investigation of the effect of cell size and thickness on the compressive properties of Aluminium honeycomb core. Honeycomb cores were compressed experimentally in in-plane and out of plane directions. The effect of sample size, cell size and thickness on the elastic modulus, yield strength and plateau stress was investigated through FEA. It was found that the mechanical response was independent upon the sample size in in-plane direction. The smallest cell size honeycomb core was deformed at higher yield stress. Similarly, with increase in cell wall thickness, the modulus of the core increased.

Theoretical analysis on the elasticity of a novel accordion cellular honeycomb core with in-plane curved beams

2018 ◽  
Vol 22 (3) ◽  
pp. 702-727 ◽  
Author(s):  
Weidong Liu ◽  
Honglin Li ◽  
Jiong Zhang ◽  
Hongda Li
Keyword(s):  
Theoretical Analysis ◽  
Thickness Ratio ◽  
Length Ratio ◽  
Honeycomb Core ◽  
Load Bearing ◽  
Flexible Skin ◽  
Out Of Plane ◽  
Vertical Beam ◽  
Beam Thickness ◽  
Honeycomb Cores

Flexible skin is an essential component for morphing wind turbine blade to maintain a smooth profile and bear aerodynamic loads during morphing. Cellular honeycomb cores with low in-plane and high out-of-plane stiffness are potential candidates for support structures of flexible skin. Honeycomb structure also requires zero Poisson’s ratio to avoid unnecessary stress and strain during one-dimensional morphing. A novel accordion cellular honeycomb core of close-to-zero Poisson’s ratio with in-plane corrugated U-type beams was proposed as a solution for these problems. The elastic properties of the structure are illustrated through a combination of theoretical analysis and finite element analysis. Results show that better in-plane morphing and out-of-plane load-bearing capabilities can be obtained with parameters of larger height-to-length ratio, spacing-to-length ratio and vertical beam to U-type beam thickness ratio as well as smaller thickness-to-length ratio. Results of comparisons on properties of the proposed honeycomb with two existing accordion honeycombs reveal that the in-plane elastic modulus of the proposed structure is as low as about 56% of that of the accordion honeycomb with V-type beams and 79% of that of the accordion honeycomb with cosine beams, showing better in-plane property but weaker out-of-plane load-bearing capability. Nevertheless, the out-of-plane load-bearing capability can be reinforced by increasing the vertical beam to U-type beam thickness ratio. Smaller driving force and less energy consumption are required by the proposed honeycomb core than conventional structures during morphing. The methods and results could be used for predictions of elasticity in design of sandwich morphing skin with similar cellular honeycomb cores.

scholarly journals Route towards efficient magnetization reversal driven by voltage control of magnetic anisotropy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roxana-Alina One ◽  
Hélène Béa ◽  
Sever Mican ◽  
Marius Joldos ◽  
Pedro Brandão Veiga ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Random Access ◽  
Low Power Consumption ◽  
Surface Anisotropy ◽  
Magnetization Dynamics ◽  
Storage Density ◽  
Switching Regime ◽  
Major Interest ◽  
Out Of Plane

AbstractThe voltage controlled magnetic anisotropy (VCMA) becomes a subject of major interest for spintronics due to its promising potential outcome: fast magnetization manipulation in magnetoresistive random access memories with enhanced storage density and very low power consumption. Using a macrospin approach, we carried out a thorough analysis of the role of the VCMA on the magnetization dynamics of nanostructures with out-of-plane magnetic anisotropy. Diagrams of the magnetization switching have been computed depending on the material and experiment parameters (surface anisotropy, Gilbert damping, duration/amplitude of electric and magnetic field pulses) thus allowing predictive sets of parameters for optimum switching experiments. Two characteristic times of the trajectory of the magnetization were analyzed analytically and numerically setting a lower limit for the duration of the pulses. An interesting switching regime has been identified where the precessional reversal of magnetization does not depend on the voltage pulse duration. This represents a promising path for the magnetization control by VCMA with enhanced versatility.

Recovery from memory failure when recalling a memorized performance: The role of musical structure and performance cues

2021 ◽  
pp. 102986492110254
Author(s):  
Roger Chaffin ◽  
Jane Ginsborg ◽  
James Dixon ◽  
Alexander P. Demos
Keyword(s):  
Vocal Music ◽  
Musical Structure ◽  
Public Performance ◽  
Memory Failure ◽  
And Performance ◽  
Written Recall ◽  
Performance Gains ◽  
Over Time

To perform reliably and confidently from memory, musicians must able to recover from mistakes and memory failures. We describe how an experienced singer (the second author) recovered from mistakes and gaps in recall as she periodically recalled the score of a piece of vocal music that she had memorized for public performance, writing out the music six times over a five-year period following the performance. Five years after the performance, the singer was still able to recall two-thirds of the piece. When she made mistakes, she recovered and went on, leaving gaps in her written recall that lengthened over time. We determined where in the piece gaps started ( losses) and ended ( gains), and compared them with the locations of structural beats (starts of sections and phrases) and performance cues ( PCs) that the singer reported using as mental landmarks to keep track of her progress through the piece during the sung, public performance. Gains occurred on structural beats where there was a PC; losses occurred on structural beats without a PC. As the singer’s memory faded over time, she increasingly forgot phrases that did not start with a PC and recovered at the starts of phrases that did. Our study shows how PCs enable musicians to recover from memory failures.

Ballistic Impact Response of Foam-Filled Sandwich Composites

2001 ◽  
Author(s):  
Uday K. Vaidya ◽  
Biju Mathew ◽  
Chad A. Ulven ◽  
Brent Sinn ◽  
Marian Velazquez
Keyword(s):  
Cost Effective ◽  
Impact Response ◽  
Sandwich Composites ◽  
High Velocity Impact ◽  
Honeycomb Core ◽  
Velocity Impact ◽  
Foam Filling ◽  
Foam Filled ◽  
Honeycomb Cores ◽  
The Cost

Abstract Sandwich composites find increasing use as flexural load bearing lightweight sub-elements rail / ground transportation and marine bodies. In recent year, alternatives to traditional foam and honeycomb cores are being sought. One such development includes filling the cells of the honeycomb core with foam. The increased surface area allows stress forces to dissipate over a larger area than that offered by the honeycomb alone. This allows for use of lowering the cost of the honeycomb cells, and thereby making the design extremely cost-effective. In the present research, phenolic impregnated honeycomb / corrugated cells with polyurethane foam filling has been considered. The intermediate and high velocity impact response of these types of sandwich constructions has been studied. The applications for such cores would be in rail and ground transportation, where impacts in the form of flying debris are common.

The Optimal Stretching Angle of Honeycomb Paper Core Based on the Fourth Strength Principle

2013 ◽  
Vol 288 ◽  
pp. 256-261 ◽  
Author(s):  
Jian Wu ◽  
Yong Long Wang ◽  
Yang Zhang ◽  
Gai Mei Zhang ◽  
Yan Ping Du
Keyword(s):  
Sampling Method ◽  
Stress Condition ◽  
Three Dimensional ◽  
Force Analysis ◽  
Honeycomb Core ◽  
Out Of Plane ◽  
Equivalent Load

The force analysis on the in-plane and out-of-plane of honeycomb core referring to some related articles is presented. during the transportation of wine, the honeycomb paper core is under three-dimensional stress. According to stress condition in the process of wine packaging and transportation, based on the fourth strength principle, the equivalent load is obtained. And the stress with different stretching angels with virtual sampling method is calculated. Thus, the optimal stretching angle of honeycomb paper is acquired, which is .

ChemInform Abstract: High Diastereoselectivity in Hosomi-Sakurai Reaction on Metal-Complexed Acyclic Enones: Role of Out-of-Plane Coordination of Lewis Acid.

ChemInform ◽  
2010 ◽  
Vol 33 (8) ◽  
pp. no-no
Author(s):  
Surojit Sur ◽  
Sunil K. Mandal ◽  
Sambasivam Ganesh ◽  
Vedavati Puranik ◽  
Amitabha Sarkar
Keyword(s):  
Lewis Acid ◽  
Out Of Plane
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