Mechanical performances of four lattice materials guided by topology optimisation

2020 ◽  
Vol 178 ◽  
pp. 339-345 ◽  
Author(s):  
Chengxing Yang ◽  
Ping Xu ◽  
Suchao Xie ◽  
Shuguang Yao
Keyword(s):  
Topology Optimisation ◽  
Lattice Materials ◽  
Mechanical Performances

scholarly journals Comparative Study on the Uniaxial Behaviour of Topology-Optimised and Crystal-Inspired Lattice Materials

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 491 ◽  
Author(s):  
Chengxing Yang ◽  
Kai Xu ◽  
Suchao Xie
Keyword(s):  
Elastic Modulus ◽  
Relative Density ◽  
Energy Absorption ◽  
Design Method ◽  
Deformation Mode ◽  
Topology Optimisation ◽  
Loading Direction ◽  
Collapse Strength ◽  
Lattice Materials ◽  
Cell Topology

This work comparatively studies the uniaxial compressive performances of three types of lattice materials, namely face-centre cube (FCC), edge-centre cube (ECC), and vertex cube (VC), which are separately generated by topology optimisation and crystal inspiration. High similarities are observed between the materials designed by these two methods. The effects of design method, cell topology, and relative density on deformation mode, mechanical properties, and energy absorption are numerically investigated and also fitted by the power law. The results illustrate that both topology-optimised and crystal-inspired lattices are mainly dominated by bending deformation mode. In terms of collapse strength and elastic modulus, VC lattice is stronger than FCC and ECC lattices because its struts are arranged along the loading direction. In addition, the collapse strength and elastic modulus of the topology-optimised FCC and ECC are close to those generated by crystal inspiration at lower relative density, but the topology-optimised FCC and ECC are obviously superior at a higher relative density. Overall, all topology-generated lattices outperform the corresponding crystal-guided lattice materials with regard to the toughness and energy absorption per unit volume.

Lightweight and low thermal conducted face-centered-cubic cementitious lattice materials (FCLMs)

2021 ◽  
pp. 113536
Author(s):  
Jian Song ◽  
Lixiao Li ◽  
Bin Yu ◽  
Yuejia Wan ◽  
Yizhuo Zhou ◽  
...  
Keyword(s):  
Face Centered Cubic ◽  
Lattice Materials ◽  
Face Centered

scholarly journals Coir Fibers Treated with Henna as a Potential Reinforcing Filler in the Synthesis of Polyurethane Composites

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1128
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Agnė Kairytė
Keyword(s):  
Mechanical Properties ◽  
High Energy ◽  
Dynamic Mechanical Properties ◽  
Milling Process ◽  
Coir Fiber ◽  
Lawsonia Inermis ◽  
Coir Fibers ◽  
Mechanical Performances ◽  
The Impact ◽  
Reinforcing Filler

In this study, coir fibers were successfully modified with henna (derived from the Lawsonia inermis plant) using a high-energy ball-milling process. In the next step, such developed filler was used as a reinforcing filler in the production of rigid polyurethane (PUR) foams. The impact of 1, 2, and 5 wt % of coir-fiber filler on structural and physico-mechanical properties was evaluated. Among all modified series of PUR composites, the greatest improvement in physico-mechanical performances was observed for PUR composites reinforced with 1 wt % of the coir-fiber filler. For example, on the addition of 1 wt % of coir-fiber filler, the compression strength was improved by 23%, while the flexural strength increased by 9%. Similar dependence was observed in the case of dynamic-mechanical properties—on the addition of 1 wt % of the filler, the value of glass transition temperature increased from 149 °C to 178 °C, while the value of storage modulus increased by ~80%. It was found that PUR composites reinforced with coir-fiber filler were characterized by better mechanical performances after the UV-aging.

scholarly journals Water-Tree Resistant Characteristics of Crosslinker-Modified-SiO2/XLPE Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1398
Author(s):  
Yong-Qi Zhang ◽  
Xuan Wang ◽  
Ping-Lan Yu ◽  
Wei-Feng Sun
Keyword(s):  
Electric Fields ◽  
Tree Growth ◽  
Mechanical Analysis ◽  
Water Molecules ◽  
Crosslinking Degree ◽  
Water Tree ◽  
Tree Resistance ◽  
Alternating Electric Fields ◽  
Trimethylolpropane Triacrylate ◽  
Mechanical Performances

Trimethylolpropane triacrylate (TMPTA) as a photoactive crosslinker is grafted onto hydrophobic nanosilica surface through click chemical reactions of mercapto double bonds to prepare the functionalized nanoparticles (TMPTA-s-SiO2), which are used to develop TMPTA-s-SiO2/XLPE nanocomposites with improvements in mechanical strength and electrical resistance. The expedited aging experiments of water-tree growth are performed with a water-knife electrode and analyzed in consistence with the mechanical performances evaluated by means of dynamic thermo-mechanical analysis (DMA) and tensile stress–strain characteristics. Due to the dense cross-linking network of polyethylene molecular chains formed on the TMPTA-modified surfaces of SiO2 nanofillers, TMPTA-s-SiO2 nanofillers are chemically introduced into XLPE matrix to acquire higher crosslinking degree and connection strength in the amorphous regions between polyethylene lamellae, accounting for the higher water-tree resistance and ameliorated mechanical performances, compared with pure XLPE and neat-SiO2/XLPE nanocomposite. Hydrophilic TMPTA molecules grafted on the nano-SiO2 surface can inhibit the condensation of water molecules into water micro-beads at insulation defects, thus attenuating the damage of water micro-beads to polyethylene configurations under alternating electric fields and thus restricting water-tree growth in amorphous regions. The intensified interfaces between TMPTA-s-SiO2 nanofillers and XLPE matrix limit the segment motions of polyethylene molecular chains and resist the diffusion of water molecules in XLPE amorphous regions, which further contributes to the excellent water-tree resistance of TMPTA-s-SiO2/XLPE nanocomposites.

Numerical and analytical study on the mechanical properties of a connector with long-fiber and metal laminated bolts for prefabricated construction

2021 ◽  
pp. 136943322110073
Author(s):  
Xiaoming Zhang ◽  
Danni Ren ◽  
Xin Liu ◽  
Sujun Guan ◽  
Xindi Yu ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Analytical Study ◽  
High Strength ◽  
Bilinear Model ◽  
Fiber Layer ◽  
Rotational Displacement ◽  
Length Direction ◽  
Plastic Phase ◽  
Fiber Metal ◽  
Mechanical Performances

To improve the mechanical performances of joints in prefabricated construction, a type of connection structure with long-fiber and metal laminated bolts (referred to as a fiber-metal connector) is proposed and investigated by simulation and theoretical methods. The results include the following: (1) The fiber layer in bolts can form a second stiffness during rotation. This mechanical characteristic improves the bearing capacities and energy dissipation ability of the connector relative to the conventional metal connector, which are expected to effectively limit the elastoplastic rotational displacement of a structure. (2) For the reason, the fiber layer can bear load in the plastic phase due to its high-strength characteristic in the length direction. (3) A bilinear model for the bearing curve of the fiber-metal connector is proposed, and equations for optimization of fiber layer thickness are obtained with a target on bearing capacity and energy dissipation ability which are approximately higher 30% and 13% than that of the conventional metal connector, respectively. This research is expected to provide a theoretical basis for the application of this fiber-metal connector in engineering and improve the safety of prefabricated structures.

scholarly journals Molecular-Level Investigation of Cycloaliphatic Epoxidised Ionic Liquids as a New Generation of Monomers for Versatile Poly(Ionic Liquids)

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1512
Author(s):  
Baris Demir ◽  
Gabriel Perli ◽  
Kit-ying Chan ◽  
Jannick Duchet-Rumeau ◽  
Sébastien Livi
Keyword(s):  
Ionic Liquids ◽  
Molecular Level ◽  
Computational Approach ◽  
Polymer Materials ◽  
Chemical Structures ◽  
Cycloaliphatic Epoxy ◽  
Polymer Models ◽  
Mechanical Performances ◽  
Dynamics Simulations ◽  
New Generation

Recently, a new generation of polymerised ionic liquids with high thermal stability and good mechanical performances has been designed through novel and versatile cycloaliphatic epoxy-functionalised ionic liquids (CEILs). From these first promising results and unexplored chemical structures in terms of final properties of the PILs, a computational approach based on molecular dynamics simulations has been developed to generate polymer models and predict the thermo–mechanical properties (e.g., glass transition temperature and Young’s modulus) of experimentally investigated CEILs for producing multi-functional polymer materials. Here, a completely reproducible and reliable computational protocol is provided to design, test and tune poly(ionic liquids) based on epoxidised ionic liquid monomers for future multi-functional thermoset polymers.

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