scholarly journals An Enhanced Three-Dimensional Auxetic Lattice Structure with Improved Property

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1008 ◽  
Author(s):  
Yingying Xue ◽  
Peixin Gao ◽  
Li Zhou ◽  
Fusheng Han
Keyword(s):  
Lattice Structure ◽  
Three Dimensional ◽  
Base Material ◽  
Compressive Property ◽  
Lattice Structures ◽  
Mechanical Behaviors ◽  
Interesting Phenomenon ◽  
Auxetic Structures ◽  
Infiltration Technique ◽  
Metal Infiltration

In order to enhance the mechanical property of auxetic lattice structures, a new enhanced auxetic lattice structure was designed by embedding narrow struts into a three-dimensional (3D) re-entrant lattice structure. A series of enhanced lattice structures with varied parameters were fabricated by 3D printing combined with the molten metal infiltration technique. Based on the method, parameter studies were performed. The enhanced auxetic lattice structure was found to exhibit superior mechanical behaviors compared to the 3D re-entrant lattice structure. An interesting phenomenon showed that increasing the diameter of connecting struts led to less auxetic and non-auxetic structures. Moreover, the compressive property of the enhanced structure also exhibited obvious dependence on the base material and compression directions. The present study can provide useful information for the design, fabrication and application of new auxetic structures with enhanced properties.

The Mechanical Properties of Hierarchical Truss-Walled Lattice Materials

2017 ◽  
Vol 09 (02) ◽  
pp. 1750027 ◽  
Author(s):  
Fangfang Sun ◽  
Qing Zheng ◽  
Hualin Fan ◽  
Daining Fang
Keyword(s):  
Mechanical Properties ◽  
Lattice Structure ◽  
Wall Structure ◽  
Lattice Structures ◽  
Mechanical Behaviors ◽  
Hierarchical Lattice ◽  
Buckling Stress ◽  
Lattice Materials ◽  
Buckling Resistance ◽  
Theoretical Analyses

To construct a hierarchical lattice structure (HLS), truss wall is introduced into ordinary lattice structure (OLS). Young’s modulus, yield strength and buckling stress of HLSs were evaluated theoretically. Failure maps of different HLSs were plotted and compared based on the theoretical analyses. It is indicated that mechanical behaviors of hexagonal HLSs made of triangular lattice walls can be greatly enhanced by the hierarchical wall structure, while properties of triangular HLSs are weakened, except the anti-buckling resistance. When HLSs are made of bending-dominated honeycomb walls, their properties will be reduced, indicating that hierarchical structure should be appropriately designed to make ultra-light structures benefit from this construction. This viewpoint is strengthened by the discussions on the performances of high order lattice structures, where only bending-dominated HLSs with stretching-dominated lattice wall benefit from the hierarchy.

Mechanical Behaviour of Three Dimensional Lattice Structures

2011 ◽  
Vol 462-463 ◽  
pp. 1302-1307
Author(s):  
Kuniharu Ushijima ◽  
Dai Heng Chen ◽  
Wesley J. Cantwell
Keyword(s):  
Mechanical Behaviour ◽  
Lattice Structure ◽  
Compressive Loading ◽  
Three Dimensional ◽  
Beam Theory ◽  
Lattice Structures ◽  
Initial Stiffness ◽  
Dimensional Lattice ◽  
Collapse Strength ◽  
The One

In this study, a theoretical analysis for predicting the mechanical properties of three dimensional lattice structures under compressive loading is proposed, and verified by comparing the analytical predictions with FEM results. This theory for estimating the initial stiffness E* is based on the classical beam theory, and the one for estimating the plastic collapse strength reflects the stress state for each lattice structure. In particular, effects of inner geometry (strand’s diameter-to-length ratio and micro-architecture) on the mechanical behaviour are discussed.

scholarly journals Toward the integration of lattice structure-based topology optimization and additive manufacturing for the design of turbomachinery components

2019 ◽  
Vol 11 (8) ◽  
pp. 168781401985978
Author(s):  
Enrico Boccini ◽  
Rocco Furferi ◽  
Lapo Governi ◽  
Enrico Meli ◽  
Alessandro Ridolfi ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Lattice Structure ◽  
Three Dimensional ◽  
Optimization Method ◽  
Lattice Structures ◽  
Stiffness Properties ◽  
Maximum Stiffness ◽  
Layer Manufacturing ◽  
Innovative Materials

Used in several industrial fields to create innovative designs, topology optimization is a method to design a structure characterized by maximum stiffness properties and reduced weights. By integrating topology optimization with additive layer manufacturing and, at the same time, by using innovative materials such as lattice structures, it is possible to realize complex three-dimensional geometries unthinkable using traditional subtractive techniques. Surprisingly, the extraordinary potential of topology optimization method (especially when coupled with additive manufacturing and lattice structures) has not yet been extensively developed to study rotating machines. Based on the above considerations, the applicability of topology optimization, additive manufacturing, and lattice structures to the fields of turbomachinery and rotordynamics is here explored. Such techniques are applied to a turbine disk to optimize its performance in terms of resonance and mass reduction. The obtained results are quite encouraging since this approach allows improving existing turbomachinery components’ performance when compared with traditional one.

scholarly journals Determination of the drag coefficient of lattice structures under wind load using porous media approach

2021 ◽  
pp. 233-233
Author(s):  
Milada Pezo ◽  
Nikola Mirkov ◽  
Vukman Bakic
Keyword(s):  
Drag Coefficient ◽  
Lattice Structure ◽  
Three Dimensional ◽  
Reynolds Stress Model ◽  
International Standards ◽  
Lattice Structures ◽  
Three Dimensional Model ◽  
Aerodynamic Forces ◽  
Wind Velocities ◽  
The Stability

The power transmitters, guyed masts and other lattice structures are exposed to wind action. The aerodynamic forces acting on tall tower constructions have crucial importance on the stability of the structure. The lattice structure drag coefficient determination is the subject of the international standards ESDU 81027 and 81028 and Eurocode 3 Part 3.1, but it can also be determined by numerical methods. For that purpose modeling using Computational Fluid Dynamics (CFD) proved to be both accurate and reliable. In this study the fluid flow around the segment of a power transmitter was simulated by a three-dimensional model, where the geometry of the segment is approximated with a porous structure having the appropriate factor of porosity, in order to simplify the geometry. We have used three representative models of turbulence, standard k-? model, RNG k-? model and Reynolds Stress Model. Drag coefficient values are extracted from the flow field and compared for all studied cases and with available experimental results from the wind tunnel. Simulations were performed for four wind velocities between 10 m/s and 30 m/s. The results are supplemented by the ones obtained by Artificial Neural Network. The aim of this study is to show how the simple turbulence model coupled with approximated geometry can be used in the analysis of the aerodynamic forces acting on the lattice structure.

scholarly journals FEM analysis of 3D lattice structures of ABS material

2021 ◽  
Vol 12 (6) ◽  
pp. 648-652
Author(s):  
Seong-Gyu Cho Et.al
Keyword(s):  
Mechanical Properties ◽  
Stress Concentration ◽  
Lattice Structure ◽  
Three Dimensional ◽  
Parametric Modeling ◽  
Lattice Structures ◽  
Filling Rate ◽  
Dimensional Lattice ◽  
Stress And Deformation ◽  
Fcc Structure

FDM is a typical additive manufacturing method. Since FDM is a method of stacking layers one by one, it generally has a flat lattice structure. In this study, by checking the distribution of stress and deformation for several lattice structures made of ABS material, it is intended to find a structure with better mechanical properties with less material. Several three-dimensional lattice structures are modeled using parametric modeling. Subsequently, a constant pressure is applied to the same area to check the stress and strain distribution. A structure with a low maximum stress value in the stress concentration region and a small amount of deformation will have the best mechanical properties. To do this, parametric modeling is performed using Inventor to model four three-dimensional lattice structures. Afterwards, use Ansys Workbench to check the stress and deformation distribution. Looking at the stress distribution, stress concentration occurred in the truss supporting the upper surface of the SC structure. In the BCC and PTC structures, stress concentration occurred at the point where the upper surface and the truss met. In the FCC structure, it can be seen that the load is distributed throughout the truss structure. Looking at the deformation distribution, both the SC and BCC structures show similar amounts of deformation. It was confirmed that the FCC structure had less maximum deformation than the PTC structure with the thickest truss. Unlike previous studies, it was confirmed that the higher the internal filling rate, the better the mechanical properties may not come out. The FDM method can obtain different mechanical properties depending on the internal lattice structure as well as the internal filling rate. In a later study, we will find a new calculation algorithm that applies variables by FDM characteristics using the data obtained by printing the actual specimen.

An Algorithm for Generating 3D Lattice Structures Suitable for Printing on a Multi-Plane FDM Printing Platform

2018 ◽  
Author(s):  
Ismayuzri B. Ishak ◽  
Mark B. Moffett ◽  
Pierre Larochelle
Keyword(s):  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Lattice Structure ◽  
Geometric Model ◽  
Three Dimensional ◽  
Manufacturing Processes ◽  
Lattice Structures ◽  
Fused Deposition ◽  
Structure Generator ◽  
Conventional Machining

Manufacturing processes for the fabrication of complex geometries involve multi-step processes when using conventional machining techniques with material removal processes. Additive manufacturing processes give leverage for fabricating complex geometric structures compared to conventional machining. The capability to fabricate 3D lattice structures is a key additive manufacturing characteristic. Most conventional additive manufacturing processes involve layer based curing or deposition to produce a three-dimensional model. In this paper, a three-dimensional lattice structure generator for multi-plane fused deposition modeling printing was explored. A toolpath for an input geometric model with an overhang structure was able to be generated. The input geometric model was able to be printed using a six degree of freedom robot arm platform. Experimental results show the achievable capabilities of the 3D lattice structure generator for use with the multi-plane platform.

scholarly journals Optimization of Generatively Encoded Multi-Material Lattice Structures for Desired Deformation Behavior

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 293
Author(s):  
Petar Ćurković
Keyword(s):  
Deformation Behavior ◽  
Lattice Structure ◽  
Three Dimensional ◽  
Residual Deformation ◽  
Population Based ◽  
Lattice Structures ◽  
Material Distribution ◽  
Natural Systems ◽  
Generative Encoding ◽  
Population Based Algorithm

Natural systems achieve favorable mechanical properties through coupling significantly different elastic moduli within a single tissue. However, when it comes to man-made materials and structures, there are a lack of methods which enable production of artifacts inspired by these phenomena. In this study, a method for design automation based on alternate deposition of soft and stiff struts within a multi-material 3D lattice structure with desired deformation behavior is proposed. These structures, once external forces are applied, conform to the geometry given in advance. For that purpose, a population-based algorithm was proposed and integrated with a multi-material physics simulator. To reduce the amount of data processed during optimization, a generative encoding method based on discrete cosine transform (DCT) was proposed. This enabled a compressed topological description and promoted symmetry in material distribution. The simulation results showed different three-dimensional lattice structures designed with proposed algorithm to meet a set of desired deformation behaviors. The relation between residual deformation error, targeted deformation geometry, and material distribution is discussed.

Compression behavior of three-dimensional printed polymer lattice structures

2018 ◽  
Vol 233 (8) ◽  
pp. 1574-1584 ◽  
Author(s):  
Mohammed Al Rifaie ◽  
Ahsan Mian ◽  
Raghavan Srinivasan
Keyword(s):  
Energy Absorption ◽  
Lattice Structure ◽  
Three Dimensional ◽  
Unit Cell ◽  
The Body ◽  
Basic Unit ◽  
Lattice Structures ◽  
Body Centered Cubic ◽  
Static Compression ◽  
Compression Behavior

This paper focuses on the compression behavior of additively manufactured or three-dimensional printed polymer lattice structures of different configurations. The body-centered cubic lattice unit cell, which has been extensively investigated for energy absorption applications, is the starting point for this research. In this study, the lattice structure based on the body-centered cubic unit cell was modified by adding vertical struts in different arrangements to create three additional configurations. Four lattice structure designs were selected for comparison: the basic unit cell (body centered cubic), body centered cubic with vertical struts added to all nodes in the lattice, body centered cubic with vertical struts added to alternate nodes in the lattice, and body centered cubic with gradient in the number of vertical bars in the lattice. Samples of all four designs were prepared using acrylonitrile–butadiene–styrene polymer by three-dimensional printing. The stiffness, failure loads, and energy absorption behaviors of all four configurations were determined under quasi-static compression loading. Specific properties were calculated by normalizing the test properties by the sample mass. It is observed from experimental data that selective placement of vertical support struts in the unit cell influences both the absolute and specific mechanical properties of lattice structures.

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