Numerical fracture analysis and model validation for disbonded honeycomb core sandwich composites

2019 ◽  
Vol 210 ◽  
pp. 231-238 ◽  
Author(s):  
Arash Farshidi ◽  
Christian Berggreen ◽  
Ralf Schäuble
Keyword(s):  
Model Validation ◽  
Fracture Analysis ◽  
Sandwich Composites ◽  
Honeycomb Core

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.

scholarly journals Deformation and Failure Behavior of Wooden Sandwich Composites with Taiji Honeycomb Core under a Three-Point Bending Test

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2325 ◽  
Author(s):  
Jingxin Hao ◽  
Xinfeng Wu ◽  
Gloria Oporto ◽  
Jingxin Wang ◽  
Gregory Dahle ◽  
...  
Keyword(s):  
Shear Failure ◽  
Dominant Role ◽  
Honeycomb Structure ◽  
Structure Design ◽  
Bending Test ◽  
Failure Behavior ◽  
Sandwich Composites ◽  
Honeycomb Core ◽  
Deformation And Failure ◽  
Three Point Bending

A new type of Taiji honeycomb structure bonded outside with wood-based laminates was characterized from a mechanical standpoint. Both theoretical and experimental methods were employed to analyze comprehensively the deformation behavior and failure mechanism under a three-point bending test. The analytical analysis reveals that a Taiji honeycomb has 3.5 times higher strength in compression and 3.44 times higher strength in shear compared with a traditional hexagonal honeycomb. Considering the strength-weight issue, the novel structure also displays an increase in compression strength of 1.75 times and shear strength of 1.72 times. Under a three-point bending test, indentation and core shear failure played the dominant role for the total failure of a wooden sandwich with Taiji honeycomb core. Typical face yield was not observed due to limited thickness-span ratio of specimens. Large spans weaken the loading level due to the contribution of global bending stress in the compressive skin to indentation failure. A set of analytical equations between mechanical properties and key structure parameters were developed to accurately predict the threshold stresses corresponding to the onset of those deformation events, which offer critical new knowledge for the rational structure design of wooden sandwich composites.

Investigation on Nonlinear Constitutive Relationship for a Honeycomb Sandwich Composite

2011 ◽  
Vol 291-294 ◽  
pp. 1025-1038
Author(s):  
Qiang Liu ◽  
Zheng Ming Huang
Keyword(s):  
Constitutive Relationship ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Honeycomb Core ◽  
Stress Strain ◽  
Nonlinear Responses ◽  
Nonlinear Stress ◽  
Honeycomb Sandwich ◽  
Aluminum Honeycomb ◽  
Honeycomb Sandwich Composite

This paper investigates nonlinear responses of honeycomb sandwich composite under externally applied loads theoretically and experimentally. In the experimental work, honeycomb sandwich composites made of an aluminum honeycomb core and glass fiber reinforced polymer (FRP) laminate surfaces were loaded under in-plane tension and out-of plane bending up to failure. Stress-strain curves or load deflection plot together with elastic moduli and ultimate strengths were obtained. An energy approach was used to establish a nonlinear constitutive relationship for the honeycomb sandwich composites. Making use of the superimposition ability of the strain energies of all of the walls of the RVE, a nonlinear constitutive relationship for the honeycomb core was obtained. The thus obtained relationship was incorporated with a laminate theory and the bridging model to analyze nonlinear responses of the honeycomb core and FRP surface sandwich composites up to failure. The composite failure was detected micromechanically, i.e., based on the failure status of its constituent aluminum core, reinforcing fiber, polymer matrix, and adhesion layer. Stiffness discount was applied respectively to the failed composing element. The predicted nonlinear stress-strain curves under tension and load-deflection relationship under three-point bending were compared with the experimental measurements. Favorable correlations have been obtained.

Improvement in skin–core adhesion of multiwalled carbon nanotubes modified carbon fiber prepreg/Nomex honeycomb sandwich composites

2017 ◽  
Vol 36 (8) ◽  
pp. 608-618 ◽  
Author(s):  
Chao Chen ◽  
Yanxia Li ◽  
Yizhuo Gu ◽  
Min Li ◽  
Zuoguang Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Multiwalled Carbon Nanotubes ◽  
Peel Test ◽  
Sandwich Composites ◽  
Honeycomb Core ◽  
Multiwalled Carbon ◽  
Honeycomb Sandwich ◽  
The Matrix ◽  
Nomex Honeycomb

An experimental investigation on the sandwich composites composed of the carbon fiber face sheets and Nomex honeycomb core has been carried out in this study. Multiwalled carbon nanotubes were added into the matrix of prepreg for converting the traditional pure resin adhesive fillet to composites. Resin viscosity was measured to evaluate the effect of the additive amount of multiwalled carbon nanotubes on the rheological properties. The size of adhesive fillet was obtained from the optical microscopy to assess the forming quality. Climbing drum peel test and edgewise compression test were employed for the mechanical assessment. The results showed that the addition of multiwalled carbon nanotubes reinforcement to epoxy resin in the prepreg was very effective in improving the skin–core adhesion. The peel load and peel energy release rate as well as the edgewise compressive strength and edgewise compressive modulus of the sandwich composites varied with different magnitudes due to the additive amount of multiwalled carbon nanotubes. Reinforcing mechanism of the adhesive fillet with multiwalled carbon nanotubes reinforcement was discussed on the basis of the fractographic observations by scanning electron microscopy.

Damage characterization of sandwich composites subjected to impact loading

2018 ◽  
Vol 22 (7) ◽  
pp. 2125-2138 ◽  
Author(s):  
Ranjith Kumar Pathipaka ◽  
Kiran Kumar Namala ◽  
Nagasrisaihari Sunkara ◽  
Chennakesava Rao Bandaru
Keyword(s):  
Contact Force ◽  
Impact Energy ◽  
Energy Levels ◽  
Free Fall ◽  
Core Material ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Honeycomb Core ◽  
Advanced Composite Materials ◽  
3D Printed

Advanced composite materials are usually optimized to achieve balance of properties for given range of applications. In recent times, researchers had worked on the sandwich composites by using different foam and metal honeycomb as a core material. In the current project, honeycomb core is prepared by using 3D printed technology. In this case of sandwich composites, cross-linked polyethylene foam and 3D-printed polylactic acid honeycomb as core and GFRP is used as face sheet. The comparison is made between polyethylene foam and 3D printed honeycomb core sandwich composite in the aspect of toughness, strength, and modulus. The present study is to characterize the damages in the sandwich structure for the amount of energy absorbed by the structures such as delamination, indentation, crushing of foams, and debonding of face sheets and core material subjected to free fall impact. The contact force versus time, contact force versus deflection of plates with respect to impact energy levels of 9.3, 16.5, and 25.7 J and impact energy versus time are determined. The current research helps in determination of core materials effecting/absorbing the damage and behavior of sandwich materials subjected to impact loads.

Fracture analysis of facesheets in sandwich composites

2004 ◽  
Vol 35 (6-8) ◽  
pp. 551-556 ◽  
Author(s):  
H Jiang ◽  
Y Huang ◽  
C Liu
Keyword(s):  
Fracture Analysis ◽  
Sandwich Composites
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