Fabrication and mechanical properties of three-dimensional enhanced lattice truss sandwich structures

2018 ◽  
Vol 22 (5) ◽  
pp. 1594-1611 ◽  
Author(s):  
Wen Yang ◽  
Jian Xiong ◽  
Li-Jia Feng ◽  
Chong Pei ◽  
Lin-Zhi Wu
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structures ◽  
Three Dimensional ◽  
Truss Structures ◽  
Unit Cell Size ◽  
Out Of Plane ◽  
Parent Alloy ◽  
Shear Characteristics ◽  
New Type ◽  
Alloy Properties

Topological-reinforcement and material-strengthening were used and employed to improve the mechanical properties of lattice truss sandwich structures. This new type of three-dimensional aluminum alloy lattice truss (named enhanced lattice truss) sandwich structure, with a relative density ranging from 1.7% to 4.7%, was designed and fabricated by interlocking and vacuum-brazing method. The out-of-plane compression and shear properties of the enhanced lattice truss sandwich structures (both as-brazed and age-hardened cores) were experimentally and analytically investigated. Good correlations between analytical predictions and experiment results were achieved. Experimental results showed that the mechanical properties of the enhanced lattice truss cores were sensitive to the unit-cell size and parent-alloy properties (i.e. inelastic buckling and tangential modulus). The compressive and shear characteristics of enhanced lattice truss sandwich structures were discussed and found superior to competing lattice truss structures in low density area (0.046–0.124 g/cm3) of material property charts. The combination of topological-reinforcement and material-strengthening provided a way to achieve lightweight sandwich structures with high specific strengths and low densities.

Numerical and experimental investigation for enhancing the energy absorption capacity of the novel three-dimensional printed sandwich structures

2021 ◽  
pp. 146442072199749
Author(s):  
H Geramizadeh ◽  
S Dariushi ◽  
S Jedari Salami
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Three Dimensional ◽  
Absorption Capacity ◽  
The Novel ◽  
Energy Absorption Capacity ◽  
Fused Deposition ◽  
Honeycomb Sandwich ◽  
Out Of Plane ◽  
Vertical Walls

The current study focuses on designing the optimal three-dimensional printed sandwich structures. The main goal is to improve the energy absorption capacity of the out-of-plane honeycomb sandwich beam. The novel Beta VI and Alpha VI were designed in order to achieve this aim. In the Beta VI, the connecting curves (splines) were used instead of the four diagonal walls, while the two vertical walls remained unchanged. The Alpha VI is a step forward on the Beta VI, which was promoted by filleting all angles among the vertical walls, created arcs, and face sheets. The two offered sandwich structures have not hitherto been provided in the literature. All models were designed and simulated by the CATIA and ABAQUS, respectively. The three-dimensional printer fabricated the samples by fused deposition modeling technique. The material properties were determined under tensile, compression, and three-point bending tests. The results are carried out by two methods based on experimental tests and finite element analyses that confirmed each other. The achievements provide novel insights into the determination of the adequate number of unit cells and demonstrate the energy absorption capacity of the Beta VI and Alpha VI are 23.7% and 53.9%, respectively, higher than the out-of-plane honeycomb sandwich structures.

Evaluation of Hydroxyapatite Film by Powder Jet Deposition after Artificial Aging

2012 ◽  
Vol 529-530 ◽  
pp. 229-232
Author(s):  
Ryo Akatsuka ◽  
Ken Matsumura ◽  
Miyoko Noji ◽  
Chihiro Nishikawa ◽  
Kei Sato ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Cycling ◽  
Vickers Hardness ◽  
Bonding Strength ◽  
Artificial Aging ◽  
Three Dimensional ◽  
Human Tooth ◽  
Significant Difference ◽  
Before And After ◽  
New Type

This study aimed to create a thick hydroxyapatite (HAp) film on the surface of a human tooth by using a newly developed powder jet deposition (PJD) device for dental handpieces, and sought to examine the microstructural and mechanical properties of the resulting HAp film. The film was evaluated on three-dimensional view, surface roughness, Vickers hardness, and bonding strength before and after artificial aging through thermal cycling (555°C) for 500 cycles (30 sec for each cycle, 20 sec of dwell time).The HAp particles in the deposited film were densely packed, and the HAp films three-dimensional microstructure and its rough surface were maintained after thermal cycling. There was no significant difference in either the HAp films Vickers hardness or the bonding strength between the film and the enamel substrate before and after thermal cycling. The HAp films created in this study demonstrated excellent microstructural and mechanical properties even after the application of thermal stress. We demonstrated the possibility of using a new type of powder jet deposition (PJD) method we developed to form a new type of interface between the tooth and biomaterials. Consequently, we propose the use of this method in new dental treatments.

A review on manufacture of polymeric foam cores for sandwich structures of complex shape in automotive applications

2021 ◽  
pp. 109963622110305
Author(s):  
Youming Chen ◽  
Raj Das
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Complex Shape ◽  
Complex Geometry ◽  
Sandwich Structures ◽  
Three Dimensional ◽  
High Density ◽  
Automotive Applications ◽  
Polymeric Foam ◽  
High Level

In this work, polymeric foam thermoforming, foam injection moulding, bead foaming and film foaming were reviewed in an effort to explore feasible processes to manufacture sandwich structures of complex geometry for automotive applications. Injection moulded foams generally suffer from high density, poor cell morphologies and unnecessary skin layers. Foamable films currently available are pressure-induced. In order for foamable films to produce foam, high uniformly-distributed pressure needs to be applied, which makes it difficult to manufacture foam parts of three-dimensional complex geometry with foamable films. The majority of commercial high-performance foam cores can be thermoformed. Ideally, thermoformed foam cores would have good mechanical properties if high-performance foam sheets are used. However, the mechanical properties of foams might be reduced during the process of thermoforming, especially around corners. Bead foaming offers a high level of freedom in foam geometry to be moulded, and inserts can be integrated into foam cores during the process of moulding. Moreover, foam cores with high density in high stressed areas and low density in low stressed areas can be manufactured with foam beads of different densities. However, due to nonhomogeneous degree of fusion and weak bonds and voids between beads, bead foams generally show mechanical properties lower than their block counterpart. Relatively speaking, thermoforming with high-performance foam sheets and moulding with high-performance foam beads hold great potentials for mass production of sandwich cores of complex geometry for automotive applications. However, further investigation on the mechanical properties of thermoformed foams and high-performance bead foams is still in need to confirm their suitability.

Identification of Damaged Bars in Three-Dimensional Redundant Truss Structures by Means of Genetic Algorithms

2007 ◽  
Vol 348-349 ◽  
pp. 229-232 ◽  
Author(s):  
Erasmo Viola ◽  
Paolo Bocchini
Keyword(s):  
Mechanical Properties ◽  
Genetic Algorithms ◽  
Mechanical Characteristics ◽  
Three Dimensional ◽  
Parametric Identification ◽  
Truss Structures ◽  
Suggested Algorithm ◽  
Lack Of Information ◽  
Non Destructive

The topic of this paper lies in the field of non-destructive parametric identification. Its objective is to evaluate the mechanical characteristics of constituent bars in existing truss structures. In particular, it locates bars with reduced mechanical properties and quantifies the loss of stiffness. The suggested algorithm takes into account plane and three-dimensional structures, both statically determinate and indeterminate. In the case where it is possible to measure strains only on some bars, the procedure uses Genetic Algorithms to overcome the lack of information.

Effect of graphene layer thickness on effective modulus of 3D CNT/Graphene nanostructures

2015 ◽  
Vol 04 (02) ◽  
pp. 1550010
Author(s):  
J. Joseph ◽  
Y. C. Lu
Keyword(s):  
Mechanical Properties ◽  
Layer Thickness ◽  
Graphene Layer ◽  
Effective Properties ◽  
Three Dimensional ◽  
Graphene Layers ◽  
Out Of Plane ◽  
Vertically Aligned ◽  
3D Nanostructure ◽  
Graphene Nanostructure

Three-dimensional CNT/Graphene nanostructure is consisted of vertically aligned carbon nanotube pillars grown directly on parallel graphene layers. The effect of graphene layer thickness on mechanical properties of the 3D nanostructure is analyzed. Overall, when the graphene layers experience the out-of-plane loading, the effective properties (Young's modulus, shear modulus, and major Poisson's ratio) of the 3D CNT/Graphene structure are significantly dependent upon the thickness of graphene layers. When the graphene layers experience the in-plane loading, the effective properties of the 3D CNT/Graphene structure depend upon the graphene thickness initially and then remain relatively unchanged as the thickness increases. It is found that the optimal performance of the 3D CNT/Graphene structure requires a minimum of thickness for the graphene layers, g/t > 5.

Mechanical properties of spider-web hierarchical honeycombs subjected to out-of-plane impact loading

2018 ◽  
Vol 22 (3) ◽  
pp. 771-796 ◽  
Author(s):  
Qiang He ◽  
Jun Feng ◽  
Yunjiang Chen ◽  
Honggen Zhou
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Structural Parameters ◽  
Element Model ◽  
Spider Web ◽  
Crushing Force ◽  
Out Of Plane ◽  
Structural Variables ◽  
New Type ◽  
Deformation Patterns

Spider-web hierarchy can be introduced by adding smaller hexagons at the centers of original cells in an underlying hexagonal network and connecting the adjacent vertices by straight beams. To examine the out-of-plane crashworthiness of this new type of hierarchical honeycomb concept, a finite element model is established and validated by existing theoretical and experimental results. Then, a parametric study on structural variables [Formula: see text] and [Formula: see text] was carried out with three different densities. The mechanical properties of hierarchical honeycombs are also compared with that of regular honeycombs. The research results show that the deformation patterns of hierarchical honeycombs can be divided into three categories. The energy absorption capability can be controlled effectively by proper adjustment of the hierarchical structural parameters. The specific energy absorption per unit mass ([Formula: see text]) of first-order spider-web hierarchical honeycomb with [Formula: see text] and second-order spider-web hierarchical honeycomb with [Formula: see text] and [Formula: see text] increases by 62.1% and 82.4%, respectively. Meanwhile, the spider-web hierarchical characteristics have less influence on the corresponding Peak Crushing Force ( PCF). Further, the mean crushing force is derived by dividing the profile into basic angle elements based on the Simplified Super Folding Element (SSFE) method. The theoretical calculation is in good agreement with the simulation results as the spider-web hierarchical honeycombs deform in Mode I. These results can provide valuable suggestions in the study and design of the new type hierarchical honeycombs.

Biotemplated facile synthesis of three‐dimensional micro/nanoporous tin oxide: improving the flammable and mechanical properties of flexible PVC

2019 ◽  
Vol 14 (8) ◽  
pp. 828-830 ◽  
Author(s):  
Weihua Meng ◽  
Weihong Wu ◽  
Weiwei Zhang ◽  
Luyao Cheng ◽  
Yunhong Jiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tin Oxide ◽  
Three Dimensional ◽  
Facile Synthesis

scholarly journals Is Dialdehyde Chitosan a Good Substance to Modify Physicochemical Properties of Biopolymeric Materials?

2021 ◽  
Vol 22 (7) ◽  
pp. 3391
Author(s):  
Sylwia Grabska-Zielińska ◽  
Alina Sionkowska ◽  
Ewa Olewnik-Kruszkowska ◽  
Katarzyna Reczyńska ◽  
Elżbieta Pamuła
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Physicochemical Properties ◽  
Silk Fibroin ◽  
Three Dimensional ◽  
Microscopy Imaging ◽  
Maximum Deformation ◽  
One Step ◽  
Chitosan Blends ◽  
Fourier Transfer Infrared Spectroscopy

The aim of this work was to compare physicochemical properties of three dimensional scaffolds based on silk fibroin, collagen and chitosan blends, cross-linked with dialdehyde starch (DAS) and dialdehyde chitosan (DAC). DAS was commercially available, while DAC was obtained by one-step synthesis. Structure and physicochemical properties of the materials were characterized using Fourier transfer infrared spectroscopy with attenuated total reflectance device (FTIR-ATR), swelling behavior and water content measurements, porosity and density observations, scanning electron microscopy imaging (SEM), mechanical properties evaluation and thermogravimetric analysis. Metabolic activity with AlamarBlue assay and live/dead fluorescence staining were performed to evaluate the cytocompatibility of the obtained materials with MG-63 osteoblast-like cells. The results showed that the properties of the scaffolds based on silk fibroin, collagen and chitosan can be modified by chemical cross-linking with DAS and DAC. It was found that DAS and DAC have different influence on the properties of biopolymeric scaffolds. Materials cross-linked with DAS were characterized by higher swelling ability (~4000% for DAS cross-linked materials; ~2500% for DAC cross-linked materials), they had lower density (Coll/CTS/30SF scaffold cross-linked with DAS: 21.8 ± 2.4 g/cm3; cross-linked with DAC: 14.6 ± 0.7 g/cm3) and lower mechanical properties (maximum deformation for DAC cross-linked scaffolds was about 69%; for DAS cross-linked scaffolds it was in the range of 12.67 ± 1.51% and 19.83 ± 1.30%) in comparison to materials cross-linked with DAC. Additionally, scaffolds cross-linked with DAS exhibited higher biocompatibility than those cross-linked with DAC. However, the obtained results showed that both types of scaffolds can provide the support required in regenerative medicine and tissue engineering. The scaffolds presented in the present work can be potentially used in bone tissue engineering to facilitate healing of small bone defects.

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