Multiaxial static strength of a 3D printed metallic lattice structure exhibiting brittle behavior

In recent years, cellular structures have attracted great deal of attention of many researchers due to their unique properties like exhibiting high strength at low density and great energy absorption. Also, the applications of cellular structures (or lattice structures) such as wing airfoil, tire, fiber and implant, are mainly used in aerospace, automotive, textile and biomedical industries respectively. In this investigation, the idea of using cellular structures in pipes made of acrylonitrile butadiene styrene (ABS) material was focused on and four different pipe types were designed as honeycomb structure model, straight rib pattern model, hybrid version of the first two models and fully solid model. Subsequently, these models were 3D printed by using FDM method and these lightweight pipes were subjected to compression tests in order to obtain stress-strain curves of these structures. Mechanical properties of lightweight pipes like elasticity modulus, specific modulus, compressive strength, specific compressive strength, absorbed energy and specific absorbed energy were calculated and compared to each other. Moreover, deformation modes were recorded during all compression tests and reported as well. The results showed that pipe models including lattice wall thickness could be preferred for the applications which don’t require too high compressive strength and their specific energy absorption values were notably capable to compete with fully solid pipe structures. In particular, rib shape lattice structure had the highest elongation while the fully solid one possessed worst ductility. Lastly, it is pointed out that 3D printing method provides a great opportunity to have a foresight about production of uncommon parts by prototyping.

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Design of Shape Reconfigurable, Highly Stretchable Honeycomb Lattice With Tunable Poisson’s Ratio

Frontiers in Materials ◽

10.3389/fmats.2021.660325 ◽

2021 ◽

Vol 8 ◽

Author(s):

Le Dong ◽

Chengru Jiang ◽

Jinqiang Wang ◽

Dong Wang

Keyword(s):

Theoretical Model ◽

Ambient Temperature ◽

Shape Memory ◽

Poisson’S Ratio ◽

Lattice Structure ◽

Poisson's Ratio ◽

Lattice Structures ◽

Straight Beam ◽

Highly Stretchable ◽

3D Printed

The mechanical behaviors of lattice structures can be tuned by arranging or adjusting their geometric parameters. Once fabricated, the lattice’s mechanical behavior is generally fixed and cannot adapt to environmental change. In this paper, we developed a shape reconfigurable, highly stretchable lattice structure with tunable Poisson’s ratio. The lattice is built based on a hexagonal honeycomb structure. By replacing the straight beam with curled microstructure, the stretchability of the lattice is significantly improved. The Poisson’s ratio is adjusted using a geometric angle. The lattice is 3D printed using a shape memory polymer. Using its shape memory effect, the lattice demonstrates tunable shape reconfigurability as the ambient temperature changes. To capture its high stretchability, tunable Poisson’s ratio and shape reconfigurability, a phase evolution model for lattice structure is used. In the theoretical model, the effects of temperature on the material’s nonlinearity and geometric nonlinearity due to the lattice structure are assumed to be decoupled. The theoretical shape change agrees well with the Finite element results, while the theoretical model significantly reduces the computational cost. Numerical results show that the geometrical parameters and the ambient temperature can be manipulated to transform the lattice into target shapes with varying Poisson’s ratios. This work provides a design method for the 3D printed lattice structures and has potential applications in flexible electronics, soft robotics, and biomedicine.

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Compressive Behaviour of 3D Printed Polymeric Gyroid Cellular Lattice Structure

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/455/1/012047 ◽

2018 ◽

Vol 455 ◽

pp. 012047 ◽

Cited By ~ 2

Author(s):

Gopal K Maharjan ◽

Sohaib Z Khan ◽

Syed H Riza ◽

SH Masood

Keyword(s):

Lattice Structure ◽

Compressive Behaviour ◽

3D Printed

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Computational design, engineering and manufacturing of a material-efficient 3D printed lattice structure

International Journal of Architectural Computing ◽

10.1177/1478077120947990 ◽

2020 ◽

Vol 18 (4) ◽

pp. 404-423

Author(s):

Roberto Naboni ◽

Anja Kunic ◽

Luca Breseghello

Keyword(s):

Lattice Structure ◽

Computational Design ◽

Material Structure ◽

Fused Deposition Modelling ◽

Design Engineering ◽

Design Development ◽

Fused Deposition ◽

Construction Methods ◽

3D Printed ◽

Scarcity Of Resources

Building with additive manufacturing is an increasingly relevant research topic in the field of Construction 4.0, where designers are seeking higher levels of automation, complexity and precision compared to conventional construction methods. As an answer to the increasing problem of scarcity of resources, the presented research exploits the potential of Fused Deposition Modelling in the production of a lightweight load-responsive cellular lattice structure at the architectural scale. The article offers an extensive insight into the computational processes involved in the design, engineering, analysis, optimization and fabrication of a material-efficient, fully 3D printed, lattice structure. Material, structure and manufacturing features are integrated within the design development in a comprehensive computational workflow. The article presents methods and results while discussing the project as a material-efficient approach to complex structures.

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Hypervelocity impact performance of 3D printed aluminum panels

2019 15th Hypervelocity Impact Symposium ◽

10.1115/hvis2019-055 ◽

2019 ◽

Author(s):

Bruce A. Davis ◽

Richard A. Hagen ◽

Robert J. McCandless ◽

Eric L. Christiansen ◽

Dana M. Lear

Keyword(s):

Lattice Structure ◽

Cell Structure ◽

Hypervelocity Impact ◽

Orbital Debris ◽

Metallic Foam ◽

Back Side ◽

Foam Core ◽

Deep Space ◽

3D Printed ◽

Aluminum Panels

Abstract NASA, JSC has been developing a light-weight, multi-functional sandwich core for habitable structure over the last several years. Typically honeycomb-based structures have been and still are a common structural component for many applications in the aerospace industry, unfortunately, honeycomb structures with an ordered, open path through the thickness have served to channel the micro-meteoroid or orbital debris into the pressure wall (instead of disassociating and decelerating). The development of a metallic open cell foam core has been explored to enhance the micro-meteoroid or orbital debris protection, which is heavier than comparable honeycomb-based structures when non-structural requirements for deep space environments (vacuum, micro-meteoroids/orbital debris, and radiation) have not been considered. While the metallic foam core represents a notable improvement in this area, there is an overwhelming need to further reduce the weight of space vehicles; especially when deep space (beyond low earth orbit, or LEO) is considered. NASA, JSC is currently developing a multi-functional sandwich panel using additive machining (3D printing), this effort evaluated the material response of a limited amount of 3D printed aluminum panels under hypervelocity impact conditions. The four 3D printed aluminum panels provided for this effort consisted of three body centric cubic lattice structure core and one kelvin cell structure core. Each panel was impacted once with nominally the same impact conditions (0.34cm diameter aluminum sphere impacting at 6.8 km/s at 0 degrees to surface normal). All tests were impacted successfully, with the aforementioned impact conditions. Each of the test panels maintained their structural integrity from the hypervelocity impact event with no damage present on the back side of the panel for any of the tests. These tests and future tests will be used to enhance development of 3D printed structural panels.

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Failure Behaviour of 3D-Printed ABS Lattice Structure under Compression

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.c6441.029320 ◽

2020 ◽

Vol 9 (3) ◽

pp. 3908-3912

Keyword(s):

Lattice Structure ◽

Compressive Load ◽

Core Material ◽

Fused Deposition Modelling ◽

Failure Behavior ◽

Stress Strain ◽

Lightweight Material ◽

Fused Deposition ◽

Layer Manufacturing ◽

3D Printed

Lattice structure is a lightweight material that can be produced using the cutting edge additive layer manufacturing process or also known as 3D printing. Lattice structure material is a periodic cellular structure material that can be utilized in various applications especially as core material in sandwich structure configuration, where the ultimate aim is to be a lightweight material with load bearing capability. Researches are yet to be done to fully understand the behavior of lattice structure materials under several loading conditions such as tensile, bending and compression. The objective of this paper is to discuss the behavior of acrylonitrile-butadiene-styrene (ABS) lattice structure material that was produced using the layer by layer manufacturing, subjected to compressive load. Lattice structure specimens with dimension 20x20x20 mm3 were designed with body centered cubic (BCC) unit cells for three sets of strut diameter size. The specimens were produced using fused deposition modelling (FDM) Cubepro 3D printer, with varying default parameters of layer thickness, print strength and print pattern. All specimens were subjected to compressive load until densification stage and the stress-strain curves of the material were plotted. The compressed specimens were observed under an optical digital microscope and a common failure behavior of 3D-printed ABS lattice structure material was highlighted. It was shown that the failure of compressed lattice structure was initiated at joint node areas due to bending tensile stress. It can be concluded that this polymer material showed hybrid between stretch and bending-dominated characteristics. This is a good indicator for lightweight material with load absorbing capability. An understanding in the failure behavior of ABS lattice structure material is enriching the knowledge on this material under stress-strain condition.

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A Pyramidal Lattice Frame: Pathways to Inversion

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455421500206 ◽

2020 ◽

pp. 2150020

Author(s):

Yue Guan ◽

Lawrence N. Virgin

Keyword(s):

Experimental Data ◽

3D Printing ◽

Numerical Simulations ◽

Physical System ◽

Discrete Model ◽

Lattice Structure ◽

Three Dimensional ◽

Lateral Load ◽

Structural Inversion ◽

3D Printed

This paper considers the load–deflection behavior of a pyramid-like, shallow lattice structure. It consists of four beams that join at a central apex and when subject to a lateral load, it exhibits a propensity to snap-through: a classical buckling phenomenon. Whether this structural inversion occurs, and the routes by which it happens, depends sensitively on geometry. Given the often sudden nature of the instability, the behavior is also examined within a dynamics context. The outcome of numerical simulations are favorably compared with experimental data extracted from the testing of three-dimensional (3D)-printed specimens. The key contributions of this paper are that despite the continuous nature of the physical system, its behavior (transient and equilibria) can be adequately described using a discrete model, and the paper also illustrates the utility of 3D-printing in an accessible research context.

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