Out-of-plane static compression and energy absorption of paper hierarchical corrugation sandwich panels

2021 ◽  
pp. 030932472110085
Author(s):  
Huineng Wang ◽  
Yanfeng Guo ◽  
Yungang Fu ◽  
Dan Li
Keyword(s):  
Yield Strength ◽  
Bearing Capacity ◽  
Energy Absorption ◽  
Sandwich Panel ◽  
Second Order ◽  
Compression Rate ◽  
Static Compression ◽  
First Order ◽  
Out Of Plane ◽  
Analytical Approaches

This study introduces the opinion of the corrugation hierarchy to develop the second-order corrugation paperboard, and explore the deformation characteristics, yield strength, and energy absorbing capacity under out-of-plane static evenly compression loading by experimental and analytical approaches. On the basis of the inclined-straight strut elements of corrugation unit and plastic hinge lines, the yield and crushing strengths of corrugation unit were analyzed. This study shows that as the compressive stress increases, the second-order corrugation core layer is firstly crushed, and the first-order corrugation structures gradually compacted until the failure of entire structure. The corrugation type has an obvious influence on the yield strength of the corrugation sandwich panel, and the yield strength of B-flute corrugation sandwich panel is wholly higher than that of the C-flute structure. At the same compression rate, the flute type has a significant impact on energy absorption, and the C-flute second-order corrugation sandwich panel has better bearing capacity than the B-flute structure. The second-order corrugation sandwich panel has a better bearing capacity than the first-order structure. The static compression rate has little effect on the yield strength and deformation mode. However, with the increase of the static compression rate, the corrugation sandwich panel has a better cushioning energy absorption and material utilization rate.

Effect of boundary factor and material property on single square honeycomb sandwich panel subjected to quasi-static compression loading

2020 ◽  
Vol 14 (4) ◽  
pp. 7348-7360
Author(s):  
Quanjin Ma ◽  
Tengfei Kuai ◽  
M.R.M Rejab ◽  
Nallapaneni Manoj Kumar ◽  
M.S Idris ◽  
...  
Keyword(s):  
Boundary Condition ◽  
Energy Absorption ◽  
Sandwich Panel ◽  
Young Modulus ◽  
Static Compression ◽  
Compression Loading ◽  
Single Side ◽  
Honeycomb Sandwich ◽  
Type 3 ◽  
Quasi Static Compression

This paper is aimed to investigate the crushing response of single square honeycomb panels under quasi-static compression loading. Two types of materials are used in this study, which refers to 100 % polylactic acid (PLA) and 70 % PLA filled 30 % carbon fibre (PLA/CF). Single honeycomb panels were fabricated through additive manufacturing technique, and assembled using slotting technique. The effect of boundary factor on the single square honeycomb panels have been studied, which refers to none, single-side, double-side boundary conditions. The effect of material properties on the crushing response has also involved. For the tensile test, it was concluded that the PLA/CF specimen offered the higher young modulus with 428.75 MPa than 360.76 MPa of PLA specimen. For the quasi-static compression test, the compressive modulus and strength of the single honeycomb sandwich panel showed 489.69 MPa and 18.32 MPa with boundary type 1, which provided the highest value compared to other two boundary condition types. Moreover, the square honeycomb sandwich panels with PLA/CF material and type 3 boundary condition offered the better crushing performance on energy absorption (EA) with 66.42 kJ and specific energy absorption (SEA) with 2282.47 kJ/kg. In addition, the crushing behaviour and failure mode were also involved and discussed in this study.

scholarly journals Influence of the Geometric Parameters on the Densification Onset Strain of Double-Walled Honeycomb Aluminum under Out-of-Plane Compression

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Jian Wang ◽  
Ying Cao
Keyword(s):  
Energy Absorption ◽  
Wall Thickness ◽  
Least Squares Method ◽  
Absorption Capacity ◽  
Geometric Design ◽  
Design Parameters ◽  
Element Analysis ◽  
Static Compression ◽  
Out Of Plane ◽  
Plane Compression

As a material widely used in various lightweight structures and energy absorbing devices, honeycomb aluminum has high specific stiffness and specific strength, excellent energy absorption capacity, and vibration damping. When evaluating the energy absorption of honeycomb aluminum under out-of-plane compression, platform stress and onset strain of densification have become important parameters studied by many scholars. In this work, based on the theory that the energy absorption efficiency determines the densification onset strain, the influence of the geometric design parameters of honeycomb aluminum on the onset strain of out-of-plane quasi-static compression densification is studied. Based on the results of the finite element analysis, the relationship between the onset strain and the geometric design parameters including cell size length and wall thickness is fitted by the least squares method. A linear relationship that the onset strain of densification will decrease with the increase of the reciprocal of cell side length and the onset strain of densification will decrease with the increase of the wall thickness is exhibited in the conclusion. This work can provide a theoretical basis for the calculation of the platform stress in the plastic deformation stage.

Effect of core corrugation angle on static compression of self-reinforced PP sandwich panels and bending energy absorption of sandwich beams

2020 ◽  
pp. 002199832096053
Author(s):  
Ali Imran ◽  
Shijie Qi ◽  
Pengcheng Shi ◽  
Muhammad Imran ◽  
Dong Liu ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Structural Parameters ◽  
Maximum Energy ◽  
Absorption Capacity ◽  
Ex Situ ◽  
Static Compression ◽  
Reinforced Polymer ◽  
Optimization Study ◽  
Out Of Plane ◽  
Optimal Stiffness

The structural weight of an electric vehicle and its material’s recyclability are the important parameters to optimize the overall cost as well as the mileage of a vehicle. Self-reinforced polymer composites (SRCs) can be potentially used for these applications because of their 100% recyclability as compared with multicomponent traditional epoxy matrix based fibre reinforced composites. In case of SRCs the fibres and matrix are synthesized from same family of polymers. An optimization study is required based on integration of material and structural parameters to reduced overall weight of the vehicles while keeping the strength up to the safety mark. We fabricated self-reinforced polypropylene (SrPP) sandwich structures through an ex-situ consolidation based fabrication method. An FEA based study was conducted to optimize the effect of core corrugation angle of sandwiched structures on out of plane compressive strength and flexural strength of SrPP sandwiched beams. The finite element study was preferred in order to save the experimental cost. Beams with 60° core corrugation angle have optimal flexural properties. The sandwiched panels with 45° corrugated core exhibited optimal stiffness while maximum energy absorption capacity was shown with 60° corrugated core sandwiched structures.

scholarly journals 3D Energy Absorption Diagram Construction of Paper Honeycomb Sandwich Panel

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Dongmei Wang ◽  
Ziyou Bai ◽  
Qianghua Liao
Keyword(s):  
Energy Absorption ◽  
Unit Volume ◽  
Sandwich Panel ◽  
Standard Condition ◽  
Optimized Design ◽  
Structural Factors ◽  
Static Compression ◽  
Honeycomb Sandwich ◽  
Paper Honeycomb ◽  
Energy Absorption Diagram

Paper honeycomb sandwich panel is an environment-sensitive material. Its cushioning property is closely related to its structural factors, the temperature and humidity, random shocks, and vibration events in the logistics environment. In order to visually characterize the cushioning property of paper honeycomb sandwich panel in different logistics conditions, the energy absorption equation of per unit volume of paper honeycomb sandwich panel was constructed by piecewise function. The three-dimensional (3D) energy absorption diagram of paper honeycomb sandwich panel was constructed by connecting the inflexion of energy absorption curve. It takes into account the temperature, humidity, strain rate, and characteristics of the honeycomb structure. On the one hand, this diagram breaks through the limitation of the static compression curve of paper honeycomb sandwich panel, which depends on the test specimen and is applicable only to the standard condition. On the other hand, it breaks through the limitation of the conventional 2D energy absorption diagram which has less information. Elastic modulus was used to normalize the plateau stress and energy absorption per unit volume. This makes the 3D energy absorption diagram universal for different material sandwich panels. It provides a new theoretical basis for packaging optimized design.

scholarly journals Design of Hierarchical Architected Lattices for Enhanced Energy Absorption

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5384
Author(s):  
Mohamad Al Nashar ◽  
Alok Sutradhar
Keyword(s):  
Relative Density ◽  
Energy Absorption ◽  
Second Order ◽  
Displacement Curve ◽  
First Order ◽  
Lattice Design ◽  
Fused Deposition ◽  
Wide Range ◽  
Absorption Performance ◽  
Hierarchical Lattices

Hierarchical lattices are structures composed of self-similar or dissimilar architected metamaterials that span multiple length scales. Hierarchical lattices have superior and tunable properties when compared to conventional lattices, and thus, open the door for a wide range of material property manipulation and optimization. Using finite element analysis, we investigate the energy absorption capabilities of 3D hierarchical lattices for various unit cells under low strain rates and loads. In this study, we use fused deposition modeling (FDM) 3D printing to fabricate a dog bone specimen and extract the mechanical properties of thermoplastic polyurethane (TPU) 85A with a hundred percent infill printed along the direction of tensile loading. With the numerical results, we observed that the energy absorption performance of the octet lattice can be enhanced four to five times by introducing a hierarchy in the structure. Conventional energy absorption structures such as foams and lattices have demonstrated their effectiveness and strengths; this research aims at expanding the design domain of energy absorption structures by exploiting 3D hierarchical lattices. The result of introducing a hierarchy to a lattice on the energy absorption performance is investigated by varying the hierarchical order from a first-order octet to a second-order octet. In addition, the effect of relative density on the energy absorption is isolated by creating a comparison between a first-order octet lattice with an equivalent relative density as a second-order octet lattice. The compression behaviors for the second order octet, dodecahedron, and truncated octahedron are studied. The effect of changing the cross-sectional geometry of the lattice members with respect to the energy absorption performance is investigated. Changing the orientation of the second-order cells from 0 to 45 degrees has a considerable impact on the force–displacement curve, providing a 20% increase in energy absorption for the second-order octet. Analytical solutions of the effective elasticity modulus for the first- and second-order octet lattices are compared to validate the simulations. The findings of this paper and the provided understanding will aid future works in lattice design optimization for energy absorption.

Experimental Analyses on Energy Absorption Property of Aluminum Honeycomb under Out-of-Plane Compression

2015 ◽  
Vol 778 ◽  
pp. 18-23
Author(s):  
Jing Hui Zhao ◽  
Jian Feng Wang ◽  
Tao Liu ◽  
Na Yang ◽  
Wen Jie Duan ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Absorption Capacity ◽  
Dynamic Impact ◽  
Energy Absorption Capacity ◽  
Static Compression ◽  
Specific Energy Absorption ◽  
Out Of Plane ◽  
Aluminum Honeycomb ◽  
Plane Compression

Aluminum honeycomb is a lightweight material with high strength and strong capacity of energy absorption. In order to research energy absorption characteristic of aluminum honeycomb material, quasi-static and dynamic out-of-plane compression experiments are carried out on a double-layer aluminum honeycomb impact attenuator of one FSAE racing car. Plateau stress (PS), specific load (SL), mass specific energy absorption (MSEA), volume specific energy absorption (VSEA) and other parameters of the tested aluminum honeycomb under both quasi-static and dynamic impact conditions are analyzed. The results show that the tested aluminum honeycomb impact attenuator has good energy absorption capacity to meet the collision requirements. Furthermore, under the condition of dynamic impact, the energy absorption capacity of this honeycomb improves compared with that under the condition of quasi static compression.

Nonlinear Analysis of Visual Evoked Potentials Elicited by Color Stimulation

1997 ◽  
Vol 36 (04/05) ◽  
pp. 315-318 ◽  
Author(s):  
K. Momose ◽  
K. Komiya ◽  
A. Uchiyama
Keyword(s):  
Visual System ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Normal Subjects ◽  
Second Order ◽  
First Order ◽  
The Relationship ◽  
Perceived Color ◽  
Second Order Nonlinearity ◽  
Visual Evoked

Abstract:The relationship between chromatically modulated stimuli and visual evoked potentials (VEPs) was considered. VEPs of normal subjects elicited by chromatically modulated stimuli were measured under several color adaptations, and their binary kernels were estimated. Up to the second-order, binary kernels obtained from VEPs were so characteristic that the VEP-chromatic modulation system showed second-order nonlinearity. First-order binary kernels depended on the color of the stimulus and adaptation, whereas second-order kernels showed almost no difference. This result indicates that the waveforms of first-order binary kernels reflect perceived color (hue). This supports the suggestion that kernels of VEPs include color responses, and could be used as a probe with which to examine the color visual system.

Imaginings

2017 ◽  
Vol 9 (3) ◽  
pp. 17-30
Author(s):  
Kelly James Clark
Keyword(s):  
Religious Tradition ◽  
Second Order ◽  
Fine Tuning ◽  
Intellectual Humility ◽  
First Order ◽  
Natural Processes ◽  
Empirically Supported ◽  
Group Violence ◽  
The World ◽  
The Universe

In Branden Thornhill-Miller and Peter Millican’s challenging and provocative essay, we hear a considerably longer, more scholarly and less melodic rendition of John Lennon’s catchy tune—without religion, or at least without first-order supernaturalisms (the kinds of religion we find in the world), there’d be significantly less intra-group violence. First-order supernaturalist beliefs, as defined by Thornhill-Miller and Peter Millican (hereafter M&M), are “beliefs that claim unique authority for some particular religious tradition in preference to all others” (3). According to M&M, first-order supernaturalist beliefs are exclusivist, dogmatic, empirically unsupported, and irrational. Moreover, again according to M&M, we have perfectly natural explanations of the causes that underlie such beliefs (they seem to conceive of such natural explanations as debunking explanations). They then make a case for second-order supernaturalism, “which maintains that the universe in general, and the religious sensitivities of humanity in particular, have been formed by supernatural powers working through natural processes” (3). Second-order supernaturalism is a kind of theism, more closely akin to deism than, say, Christianity or Buddhism. It is, as such, universal (according to contemporary psychology of religion), empirically supported (according to philosophy in the form of the Fine-Tuning Argument), and beneficial (and so justified pragmatically). With respect to its pragmatic value, second-order supernaturalism, according to M&M, gets the good(s) of religion (cooperation, trust, etc) without its bad(s) (conflict and violence). Second-order supernaturalism is thus rational (and possibly true) and inconducive to violence. In this paper, I will examine just one small but important part of M&M’s argument: the claim that (first-order) religion is a primary motivator of violence and that its elimination would eliminate or curtail a great deal of violence in the world. Imagine, they say, no religion, too.Janusz Salamon offers a friendly extension or clarification of M&M’s second-order theism, one that I think, with emendations, has promise. He argues that the core of first-order religions, the belief that Ultimate Reality is the Ultimate Good (agatheism), is rational (agreeing that their particular claims are not) and, if widely conceded and endorsed by adherents of first-order religions, would reduce conflict in the world.While I favor the virtue of intellectual humility endorsed in both papers, I will argue contra M&M that (a) belief in first-order religion is not a primary motivator of conflict and violence (and so eliminating first-order religion won’t reduce violence). Second, partly contra Salamon, who I think is half right (but not half wrong), I will argue that (b) the religious resources for compassion can and should come from within both the particular (often exclusivist) and the universal (agatheistic) aspects of religious beliefs. Finally, I will argue that (c) both are guilty, as I am, of the philosopher’s obsession with belief. 

Evidence for general base catalysis by protic solvents in a kinetic study of alcoholyses and hydrolyses of 1-(phenoxycarbonyl)pyridinium ions under both solvolytic and non-solvolytic conditions

2009 ◽  
Vol 74 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Dennis N. Kevill ◽  
Byoung-Chun Park ◽  
Jin Burm Kyong
Keyword(s):  
Second Order ◽  
Base Catalysis ◽  
Substitution Reactions ◽  
Third Order ◽  
Methoxy Derivative ◽  
First Order ◽  
General Base ◽  
Protic Solvents ◽  
Kinetics Of ◽  
Pyridinium Ions

The kinetics of nucleophilic substitution reactions of 1-(phenoxycarbonyl)pyridinium ions, prepared with the essentially non-nucleophilic/non-basic fluoroborate as the counterion, have been studied using up to 1.60 M methanol in acetonitrile as solvent and under solvolytic conditions in 2,2,2-trifluoroethan-1-ol (TFE) and its mixtures with water. Under the non- solvolytic conditions, the parent and three pyridine-ring-substituted derivatives were studied. Both second-order (first-order in methanol) and third-order (second-order in methanol) kinetic contributions were observed. In the solvolysis studies, since solvent ionizing power values were almost constant over the range of aqueous TFE studied, a Grunwald–Winstein equation treatment of the specific rates of solvolysis for the parent and the 4-methoxy derivative could be carried out in terms of variations in solvent nucleophilicity, and an appreciable sensitivity to changes in solvent nucleophilicity was found.

Metaontology

2018 ◽  
Author(s):  
Uriah Kriegel
Keyword(s):  
Second Order ◽  
Order Property ◽  
First Order ◽  
First Approximation

Brentano’s theory of judgment serves as a springboard for his conception of reality, indeed for his ontology. It does so, indirectly, by inspiring a very specific metaontology. To a first approximation, ontology is concerned with what exists, metaontology with what it means to say that something exists. So understood, metaontology has been dominated by three views: (i) existence as a substantive first-order property that some things have and some do not, (ii) existence as a formal first-order property that everything has, and (iii) existence as a second-order property of existents’ distinctive properties. Brentano offers a fourth and completely different approach to existence talk, however, one which falls naturally out of his theory of judgment. The purpose of this chapter is to present and motivate Brentano’s approach.

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