scholarly journals Shear Deformation Response for Three-Dimensional Lattice Structures(2nd Report, Effects of Unit Cell Geometry in a Lattice Structure)

2011 ◽  
Vol 77 (781) ◽  
pp. 1417-1432
Author(s):  
Kuniharu USHIJIMA ◽  
Dai-Heng CHEN ◽  
Wesley James CANTWELL ◽  
Masataka SEO
Keyword(s):  
Shear Deformation ◽  
Lattice Structure ◽  
Three Dimensional ◽  
Unit Cell ◽  
Lattice Structures ◽  
Cell Geometry ◽  
Dimensional Lattice ◽  
Deformation Response

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 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.

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.

Determination of Optimal Unit-Cell Size of Homogeneous Conformal Unit-Cell Lattice Structure Using Solid Shape Matching

2016 ◽  
Author(s):  
Mahmoud A. Alzahrani ◽  
Seung-Kyum Choi
Keyword(s):  
Cell Size ◽  
Solid Body ◽  
Strain Energy ◽  
Lattice Structure ◽  
Weight Ratio ◽  
Unit Cell ◽  
Optimal Size ◽  
Lattice Structures ◽  
Unit Cell Size ◽  
Unit Cells

With rapid developments and advances in additive manufacturing technology, lattice structures have gained considerable attention. Lattice structures are capable of providing parts with a high strength to weight ratio. Most work done to reduce computational complexity is concerned with determining the optimal size of each strut within the lattice unit-cells but not with the size of the unit-cell itself. The objective of this paper is to develop a method to determine the optimal unit-cell size for homogenous periodic and conformal lattice structures based on the strain energy of a given structure. The method utilizes solid body finite element analysis (FEA) of a solid counter-part with a similar shape as the desired lattice structure. The displacement vector of the lattice structure is then matched to the solid body FEA displacement results to predict the structure’s strain energy. This process significantly reduces the computational costs of determining the optimal size of the unit cell since it eliminates FEA on the actual lattice structure. Furthermore, the method can provide the measurement of relative performances from different types of unit-cells. The developed examples clearly demonstrate how we can determine the optimal size of the unit-cell based on the strain energy. Moreover, the computational cost efficacy is also clearly demonstrated through comparison with the FEA and the proposed method.

OPTIMIZATION OF VIBRATION BANDGAPS IN THREE-DIMENSIONAL LATTICE STRUCTURES

2021 ◽  
Author(s):  
Rubens Gonçalves Salsa Junior ◽  
Thiago de Paula Sales ◽  
Domingos Rade
Keyword(s):  
Three Dimensional ◽  
Lattice Structures ◽  
Dimensional Lattice

Stress-Constrained Design of Functionally Graded Lattice Structures With Spline-Based Dimensionality Reduction

2019 ◽  
Author(s):  
Jenmy Zimi Zhang ◽  
Conner Sharpe ◽  
Carolyn Conner Seepersad
Keyword(s):  
Three Dimensional ◽  
Surrogate Models ◽  
Functionally Graded ◽  
Unit Cell ◽  
Cell Stiffness ◽  
Stress Constraint ◽  
Compact Representation ◽  
Lattice Structures ◽  
Worst Case ◽  
Graded Lattice

Abstract This paper presents a computationally tractable approach for designing lattice structures for stiffness and strength. Yielding in the mesostructure is determined by a worst-case stress analysis of the homogenization simulation data. This provides a physically meaningful, generalizable, and conservative way to estimate structural failure in three-dimensional functionally graded lattice structures composed of any unit cell architectures. Computational efficiency of the design framework is ensured by developing surrogate models for the unit cell stiffness and strength as a function of density. The surrogate models are then used in the coarse-scale analysis and synthesis. The proposed methodology further uses a compact representation of the material distribution via B-splines, which reduces the size of the design parameter space while ensuring a smooth density variation that is desirable for manufacturing. The proposed method is demonstrated in compliance minimization studies using two types of unit cells with distinct mechanical properties. The effects of B-spline mesh refinement and the presence of a stress constraint on the optimization results are also investigated.

Design and Analysis of Lattice Structures for Additive Manufacturing

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Christiane Beyer ◽  
Dustin Figueroa
Keyword(s):  
Additive Manufacturing ◽  
Lattice Structure ◽  
Cost Savings ◽  
Unit Cell ◽  
Cnc Machining ◽  
Numerical Control ◽  
Full Potential ◽  
Lattice Structures ◽  
Cell Structures ◽  
Bending Load

Additive manufacturing (AM) enables time and cost savings in the product development process. It has great potential in the manufacturing of lighter parts or tools by the embedding of cellular/lattice structures that consume less material while still distributing the necessary strength. Less weight and less material consumption can lead to enormous energy and cost savings. Although AM has come a long way over the past 25–30 years since the first technology was invented, the design of parts and tools that capitalize on the technology do not yet encompass its full potential. Designing for AM requires departing from traditional design guidelines and adopting new design considerations and thought structures. Where previous manufacturing techniques (computer numerical control (CNC) machining, casting, etc.) often necessitated solid parts, AM allows for complex parts with cellular and lattice structure implementation. The lattice structure geometry can be manipulated to deliver the level of performance required of the part. The development and research of different cell and lattice structures for lightweight design is of significant interest for realizing the full potential of AM technologies. The research not only includes analysis of existing software tools to design and optimize cell structures, but it also involves design consideration of different unit cell structures. This paper gives a solid foundation of an experimental analysis of additive manufactured parts with diverse unit cell structures in compression and flexural tests. Although the research also includes theoretical finite element analysis (FEA) of the models, the results are not considered here. As an introduction, the paper briefly explains the basics of stress and strain relationship and summarizes the test procedure and methods. The tests concentrate primarily on the analysis of 3D printed polymer parts manufactured using PolyJet technology. The results show the behavior of test specimens with different cell structures under compression and bending load. However, the research has been extended and is still ongoing with an analysis of selective laser melted test specimens in aluminum alloy AlSi10Mg.

scholarly journals Stress-Constrained Design of Functionally Graded Lattice Structures With Spline-Based Dimensionality Reduction

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Jenmy Zimi Zhang ◽  
Conner Sharpe ◽  
Carolyn Conner Seepersad
Keyword(s):  
Three Dimensional ◽  
Surrogate Models ◽  
Functionally Graded ◽  
Unit Cell ◽  
Cell Stiffness ◽  
Stress Constraint ◽  
Compact Representation ◽  
Lattice Structures ◽  
Worst Case ◽  
Graded Lattice

Abstract This paper presents a computationally tractable approach for designing lattice structures for stiffness and strength. Yielding in the mesostructure is determined by a worst-case stress analysis of the homogenization simulation data. This provides a physically meaningful, generalizable, and conservative way to estimate structural failure in three-dimensional functionally graded lattice structures composed of any unit cell architectures. Computational efficiency of the design framework is ensured by developing surrogate models for the unit cell stiffness and strength as a function of density. The surrogate models are then used in the coarse-scale analysis and synthesis. The proposed methodology further uses a compact representation of the material distribution via B-splines, which reduces the size of the design parameter space while ensuring a smooth density variation that is desirable for manufacturing. The proposed method is demonstrated in compliance with minimization studies using two types of unit cells with distinct mechanical properties. The effects of B-spline mesh refinement and the presence of a stress constraint on the optimization results are also investigated.

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