Mechanical Properties of Additively Manufactured Periodic Cellular Structures and Design Variations

2021 ◽  
pp. 1-48
Author(s):  
Derek G. Spear ◽  
Anthony N. Palazotto ◽  
Ryan A. Kemnitz
Keyword(s):  
Mechanical Properties ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Material Selection ◽  
Cellular Structures ◽  
New Approach ◽  
Triply Periodic ◽  
Superior Mechanical Properties ◽  
Manufacturing Technologies ◽  
Surface Thickness

Abstract Advances in manufacturing technologies have led to the development of a new approach to material selection, in that architectured designs can be created to achieve a specific mechanical objective. Cellular lattice structures have been at the forefront of this movement due to the ability to tailor their mechanical response through tuning of the topology, surface thickness, cell size, and cell density. In this work, the mechanical properties of additively manufactured periodic cellular lattices are evaluated and compared, primarily through the topology and surface thickness parameters. The evaluated lattices were based upon triply periodic minimal surfaces (TPMS), including novel variations on the base TPMS designs, which have not been tested previously. These lattices were fabricated out of Inconel 718 (IN718) through the selective laser melting (SLM) process. Specimens were tested under uniaxial compression, and the resultant mechanical properties were determined. Further discussion of the fabrication quality and deformation behavior of the lattices are provided. Results of this work indicate that the Diamond TPMS lattice has superior mechanical properties to the other lattices tested. Additionally, with the exception of the Primitive TPMS lattice, the base TPMS designs exhibited superior mechanical performance to their derivative lattice designs.

scholarly journals Modeling Symmetric Minimal Surfaces by Mesh Subdivision

2021 ◽  
pp. 249-254
Author(s):  
Stefano Rosso ◽  
Andrea Curtarello ◽  
Federico Basana ◽  
Luca Grigolato ◽  
Roberto Meneghello ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Minimal Surfaces ◽  
Mean Curvature ◽  
Geometric Modeling ◽  
Mechanical Response ◽  
Triply Periodic Minimal Surfaces ◽  
Triply Periodic ◽  
Enhanced Properties ◽  
Manufacturing Technologies ◽  
Zero Mean Curvature

AbstractThanks to the great diffusion of additive manufacturing technologies, the interest in lattice structures is growing. Among them, minimal surfaces are characterized by zero mean curvature, allowing enhanced properties such as mechanical response and fluidynamic behavior. Recent works showed a method for geometric modeling triply periodic minimal surfaces (TPMS) based on subdivision surface. In this paper, the deviation between the subdivided TPMS and the implicit defined ones is investigated together with mechanical properties computed by numerical methods. As a result, a model of mechanical properties as a function of the TPMS thickness and relative density is proposed.

Novel and Efficient Mathematical and Computational Methods for the Analysis and Architecting of Ultralight Cellular Materials and their Macrostructural Responses

2021 ◽  
pp. 199-246
Author(s):  
Maryam Tabatabaei ◽  
Satya N. Atluri
Keyword(s):  
Composite Materials ◽  
Three Dimensional ◽  
Mechanical Efficiency ◽  
Cellular Structures ◽  
Advanced Manufacturing Technologies ◽  
Low Weight ◽  
Superior Mechanical Properties ◽  
Architectural Principles ◽  
Manufacturing Technologies ◽  
Media Lab

Nature benefits from high stiffness and strength low-weight materials by involving architected cellular structures. For example, trabecular bone, beaks and bones of birds, plant parenchyma, and sponge optimize superior mechanical properties at low density by implementing a highly porous, complex architected cellular core [25]. The same engineering and architectural principles at the material scale have been used by humankind to develop materials with higher mechanical efficiency and lower mass in many weight-critical applications. The emergence of advanced manufacturing technologies such as additive manufacturing and three-dimensional (3D) laser lithography offer the opportunity to fabricate ultralight metallic and composite materials with intricate cellular architecture to location-specific requirements. For example, the world’s lightest metal [26,32], Fig. 7.1, and reversibly assembled ultralight carbon-fiber-reinforced composite materials [4], Fig. 7.2, with architected cellular structures have been recently fabricated at Hughes Research Laboratories (HRL) in California and MIT Media Lab-Center for Bits and Atoms, respectively.

scholarly journals Effect of Short Attritor-Milling of Magnesium Alloy Powder Prior to Spark Plasma Sintering

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3973
Author(s):  
Peter Minárik ◽  
Mária Zemková ◽  
Michal Knapek ◽  
Stanislav Šašek ◽  
Jan Dittrich ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Spark Plasma Sintering ◽  
Alloy Powder ◽  
Mechanical Performance ◽  
Milled Powder ◽  
Plasma Sintering ◽  
Attritor Milling ◽  
Spark Plasma ◽  
Superior Mechanical Properties

The spark plasma sintering (SPS) technique was employed to prepare compacts from (i) gas-atomized and (ii) attritor-milled AE42 magnesium powder. Short attritor-milling was used mainly to disrupt the MgO shell covering the powder particles and, in turn, to enhance consolidation during sintering. Compacts prepared by SPS from the milled powder featured finer microstructures than compacts consolidated from gas-atomized powder (i.e., without milling), regardless of the sintering temperatures in the range of 400–550 °C. Furthermore, the grain growth associated with the increase in the sintering temperature in these samples was less pronounced than in the samples prepared from gas-atomized particles. Consequently, the mechanical properties were significantly enhanced in the material made of milled powder. Apart from grain refinement, the improvements in mechanical performance were attributed to the synergic effect of the irregular shape of the milled particles and better consolidation due to effectively disrupted MgO shells, thus suppressing the crack formation and propagation during loading. These results suggest that relatively short milling of magnesium alloy powder can be effectively used to achieve superior mechanical properties during consolidation by SPS even at relatively low temperatures.

scholarly journals Bone-inspired microarchitectures achieve enhanced fatigue life

2019 ◽  
Vol 116 (49) ◽  
pp. 24457-24462 ◽  
Author(s):  
Ashley M. Torres ◽  
Adwait A. Trikanad ◽  
Cameron A. Aubin ◽  
Floor M. Lambers ◽  
Marysol Luna ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Cancellous Bone ◽  
High Performance ◽  
Mechanical Performance ◽  
Lattice Structures ◽  
Structural Elements ◽  
Naturally Occurring ◽  
Superior Mechanical Properties ◽  
The Cost

Microarchitectured materials achieve superior mechanical properties through geometry rather than composition. Although ultralightweight microarchitectured materials can have high stiffness and strength, application to durable devices will require sufficient service life under cyclic loading. Naturally occurring materials provide useful models for high-performance materials. Here, we show that in cancellous bone, a naturally occurring lightweight microarchitectured material, resistance to fatigue failure is sensitive to a microarchitectural trait that has negligible effects on stiffness and strength—the proportion of material oriented transverse to applied loads. Using models generated with additive manufacturing, we show that small increases in the thickness of elements oriented transverse to loading can increase fatigue life by 10 to 100 times, far exceeding what is expected from the associated change in density. Transversely oriented struts enhance resistance to fatigue by acting as sacrificial elements. We show that this mechanism is also present in synthetic microlattice structures, where fatigue life can be altered by 5 to 9 times with only negligible changes in density and stiffness. The effects of microstructure on fatigue life in cancellous bone and lattice structures are described empirically by normalizing stress in traditional stress vs. life (S-N) curves by √ψ, where ψ is the proportion of material oriented transverse to load. The mechanical performance of cancellous bone and microarchitectured materials is enhanced by aligning structural elements with expected loading; our findings demonstrate that this strategy comes at the cost of reduced fatigue life, with consequences to the use of microarchitectured materials in durable devices and to human health in the context of osteoporosis.

Mapping the structure, composition and mechanical properties of bamboo

2006 ◽  
Vol 21 (8) ◽  
pp. 1969-1976 ◽  
Author(s):  
I.M. Low ◽  
Z.Y. Che ◽  
B.A. Latella
Keyword(s):  
Mechanical Properties ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Damage Zone ◽  
Elastic Stiffness ◽  
Indentation Creep ◽  
Interfacial Damage ◽  
Depth Profiles ◽  
High Toughness ◽  
Synchrotron Radiation Diffraction

The structure, composition, and mechanical response of Australian bamboo were investigated. The graded structure, composition, and mechanical properties were confirmed by depth profiles obtained using synchrotron radiation diffraction and Vickers indentation. The mechanical performance of bamboo was strongly dependent on age. Results indicated that young bamboo has a higher strength, elastic stiffness, and fracture toughness than its older counterpart does. In addition, the hardness of bamboo is both load dependent and time dependent as a result of an expanding interfacial damage zone and indentation creep, respectively. In addition to fiber debonding, crack deflection and crack-bridging are the major energy dissipative processes for imparting a high toughness in bamboo.

Mechanical properties of thermoplastic parts produced by fused deposition modeling:a review

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ali Alperen Bakır ◽  
Resul Atik ◽  
Sezer Özerinç
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Material Selection ◽  
Current Knowledge ◽  
Synergistic Effects ◽  
Future Research ◽  
Content Type ◽  
Fused Deposition

Purpose This paper aims to provide an overview of the recent findings of the mechanical properties of parts manufactured by fused deposition modeling (FDM). FDM has become a widely used technique for the manufacturing of thermoplastic parts. The mechanical performance of these parts under service conditions is difficult to predict due to the large number of process parameters involved. The review summarizes the current knowledge about the process-property relationships for FDM-based three-dimensional printing. Design/methodology/approach The review first discusses the effect of material selection, including pure thermoplastics and polymer-matrix composites. Second, process parameters such as nozzle temperature, raster orientation and infill ratio are discussed. Mechanisms that these parameters affect the specimen morphology are explained, and the effect of each parameter on the strength of printed parts are systematically presented. Findings Mechanical properties of FDM-produced parts strongly depend on process parameters and are usually lower than injection-molded counterparts. There is a need to understand the effect of each parameter and any synergistic effects involved better. Practical implications Through the optimization of process parameters, FDM has the potential to produce parts with strength values matching those produced by conventional methods. Further work in the field will make the FDM process more suitable for the manufacturing of load-bearing components. Originality/value This paper presents a critical assessment of the current knowledge about the mechanical properties of FDM-produced parts and suggests future research directions.

ENGINEERING ORIENTATION IN BLOCK COPOLYMERS FOR APPLICATION TO PROSTHETIC HEART VALVES

2010 ◽  
Vol 03 (04) ◽  
pp. 249-252 ◽  
Author(s):  
JOANNA STASIAK ◽  
GEOFF D. MOGGRIDGE ◽  
ADRIANO ZAFFORA ◽  
ANNA PANDOLFI ◽  
MARIA L. COSTANTINO
Keyword(s):  
Mechanical Properties ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Long Range ◽  
Heart Valves ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Prosthetic Heart Valves ◽  
Anisotropic Mechanical Properties ◽  
Butadiene Styrene

This study demonstrates how the mechanical performance of polymeric material can be enhanced by morphology and phase orientation of block copolymers to achieve desired anisotropic mechanical properties. The material used was a new Kraton block copolymer consisting of styrene-isoprene-butadiene-styrene blocks having cylindrical morphology. We report a method of achieving long range uniaxial as well as biaxial orientation of block copolymer. Each microstructural organization results in a specific mechanical performance, which depends on the direction of the applied deformation. The method of tailoring mechanical properties by engineering microstructure may be successfully utilized to applications requiring anisotropic mechanical response, such as prosthetic heart valves.

scholarly journals Compressive Behaviour of Additively Manufactured Lattice Structures: A Review

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 207
Author(s):  
Solomon O. Obadimu ◽  
Kyriakos I. Kourousis
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Lattice Structure ◽  
Evolutionary Process ◽  
Lattice Structures ◽  
Compressive Behaviour ◽  
Technology Industry ◽  
Unit Cells ◽  
Superior Mechanical Properties ◽  
And Performance

Additive manufacturing (AM) technology has undergone an evolutionary process from fabricating test products and prototypes to fabricating end-user products—a major contributing factor to this is the continuing research and development in this area. AM offers the unique opportunity to fabricate complex structures with intricate geometry such as the lattice structures. These structures are made up of struts, unit cells, and nodes, and are being used not only in the aerospace industry, but also in the sports technology industry, owing to their superior mechanical properties and performance. This paper provides a comprehensive review of the mechanical properties and performance of both metallic and non-metallic lattice structures, focusing on compressive behaviour. In particular, optimisation techniques utilised to optimise their mechanical performance are examined, as well the primary factors influencing mechanical properties of lattices, and their failure mechanisms/modes. Important AM limitations regarding lattice structure fabrication are identified from this review, while the paucity of literature regarding material extruded metal-based lattice structures is discussed.

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