The Design of Optimal Lattice Structures Manufactured by Maypole Braiding

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Austin Gurley ◽  
David Beale ◽  
Royall Broughton ◽  
David Branscomb
Keyword(s):  
Carbon Fiber ◽  
Full Advantage ◽  
Cross Sections ◽  
Design Methodology ◽  
Lattice Structure ◽  
Axial Stiffness ◽  
Lattice Structures ◽  
Braided Composite ◽  
Composite Lattice ◽  
Round Cross

Beginning with the maypole braiding process and its inherent constraints, we develop a design methodology for the realization of optimal braided composite lattice structures. This process requires novel geometric, mechanical, and optimization procedures for comprehensive design-ability, while taking full advantage of the capabilities of maypole braiding. The composite lattice structures are braided using yarns comprised of multiple prepreg carbon fiber (CF) tows that are themselves consolidated in a thin braided jacket to maintain round cross sections. Results show that optimal lattice-structure tubes provide significant improvement over smooth-walled CF tubes and nonoptimal lattices in torsion and bending, while maintaining comparable axial stiffness (AE).

scholarly journals Analysis of a Preliminary Design Approach for Conformal Lattice Structures

2021 ◽  
Vol 11 (23) ◽  
pp. 11449
Author(s):  
Pierandrea Dal Fabbro ◽  
Stefano Rosso ◽  
Alessandro Ceruti ◽  
Diego Boscolo Bozza ◽  
Roberto Meneghello ◽  
...  
Keyword(s):  
Cross Sections ◽  
Geometric Modeling ◽  
Lattice Structure ◽  
Optimization Method ◽  
Free Form ◽  
Size Optimization ◽  
Lattice Structures ◽  
Finite Element Software ◽  
Beam Analysis ◽  
Prediction Of Mechanical Properties

An important issue when designing conformal lattice structures is the geometric modeling and prediction of mechanical properties. This paper presents suitable methods for obtaining optimized conformal lattice structures and validating them without the need for high computational power and time, enabling the designer to have quick feedback in the first design phases. A wireframe modeling method based on non-uniform rational basis spline (NURBS) free-form deformation (FFD) that allows conforming a regular lattice structure inside a design space is presented. Next, a previously proposed size optimization method is adopted for optimizing the cross-sections of lattice structures. Finally, two different commercial finite element software are involved for the validation of the results, based on Euler–Bernoulli and Timoshenko beam theories. The findings highlight the adaptability of the NURBS-FFD modeling approach and the reliability of the size optimization method, especially in stretching-dominated cell topologies and load conditions. At the same time, the limitation of the structural beam analysis when dealing with thick beams is noted. Moreover, the behavior of different kinds of lattices was investigated.

Buckling and vibration of composite lattice elliptical cylindrical shells

2017 ◽  
Vol 233 (7) ◽  
pp. 1255-1266 ◽  
Author(s):  
AV Lopatin ◽  
EV Morozov ◽  
AV Shatov
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Lattice Structure ◽  
Cylindrical Shells ◽  
Mode Shapes ◽  
Multiple Use ◽  
Elliptical Cross ◽  
Fundamental Frequencies ◽  
Composite Lattice ◽  
Lattice Shells

An approach to the finite element study of the buckling and dynamic behaviour of composite lattice cylindrical shells with elliptical cross sections is presented in this paper. The lattice shells are modelled as three-dimensional frame structures composed of curvilinear ribs using beam finite elements. A specialised algorithm is developed to generate the finite element model of the lattice shells based on multiple use of the repeating unit cell of the composite lattice structure. Using this model, the buckling behaviour of the shells subjected to axial loading and transverse bending are investigated. Fundamental frequencies of axial and transverse vibrations of the shells with a massive rigid disk attached to their ends are determined based on the modelling approach proposed in this work. The effects of parameters of the lattice structure on the values of critical buckling loads, buckling and vibration mode shapes, and the fundamental frequencies are examined using parametric analyses. Based on the computations, the angles of orientation of helical ribs delivering maximum critical loads and fundamental frequencies are identified. The results of this study can be applied to the design of the composite tubular bodies of spacecraft made in the form of cylindrical lattice shells with elliptical cross sections.

On the Compression Mechanism of the Composite Lattice Structures

2015 ◽  
Vol 24 (5) ◽  
pp. 096369351502400
Author(s):  
Yunpeng Jiang
Keyword(s):  
Porous Material ◽  
Analytical Model ◽  
Phenomenological Model ◽  
Volume Fraction ◽  
Lattice Structure ◽  
Void Volume Fraction ◽  
Lattice Structures ◽  
Compression Mechanism ◽  
Composite Lattice ◽  
Comparison With Experiments

The composite lattice structure is regarded as a porous material in the present work, and then the corresponding compression mechanism is clearly interpreted by a simple but reasonable phenomenological model, which containing a damage element to account for the micro-buckling progression and a reinforcement element for the reduction of void volume fraction. Moreover, a micromechanics model is developed to quantitatively characterize the stiffness degradation induced by the micro-buckling deformation. The accuracy of the analytical model is verified by the comparison with experiments.

Analysis of the compression behaviour of different composite lattice designs

2017 ◽  
Vol 52 (6) ◽  
pp. 715-729 ◽  
Author(s):  
R Umer ◽  
Z Barsoum ◽  
HZ Jishi ◽  
K Ushijima ◽  
WJ Cantwell
Keyword(s):  
Lattice Structure ◽  
Numerical Models ◽  
Fibre Volume ◽  
Lattice Structures ◽  
Compression Tests ◽  
Static Compression ◽  
Bcc Lattice ◽  
Compression Behaviour ◽  
Composite Lattice ◽  
Quasi Static Compression

Four all-composite lattice designs were produced using a lost-mould procedure that involved inserting carbon fibre tows through holes in a core. Following resin infusion and curing, samples were heated to melt the core, leaving well-defined lattice structures based on what are termed BCC, BCCz, FCC and F2BCC designs. Analytical and numerical models for predicting the mechanical properties of the four designs are presented and these results are compared with the experimental data from the quasi-static compression tests. Compression tests on the four lattice structures indicated that the F2BCC lattice offered the highest compression strength, although when normalized by relative density, the BCCz lattice structure out-performed other structures. Similarly, the specific compression strengths were found to be superior to those of more traditional core materials. A number of failure mechanisms were also highlighted, including strut buckling, fracture at the strut-skin joints and debonding of reinforcing members at the central nodes. Finally, it is believed that the properties of these lattices can be further increased using higher fibre volume fractions.

scholarly journals Anisotropy of a Selective Laser-Melted Ti–6Al–4V Lattice Structure

2021 ◽  
Author(s):  
Dingye YAO ◽  
Weixing ZHOU ◽  
Yuli MA ◽  
Bo He
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Cross Sections ◽  
Lattice Structure ◽  
Physical Models ◽  
Image Correlation ◽  
Isotropic Hardening ◽  
Lattice Structures ◽  
Compression Tests ◽  
Small Cross Section

Abstract Selective laser melting (SLM) is a widely adopted additive manufacturing process for the preparation of metallic lattice structures. However, it causes a build-direction-dependent anisotropy of morphologies, microstructures, and mechanical properties, making it difficult to predict the behavior and performance of lattice structures. In this study, tensile samples with different cross-sections and build directions (BDs) were fabricated by SLM. The anisotropic morphology, microstructure, and tensile properties were observed and measured using optical microscopy, scanning electron microscopy, and three-dimensional digital image correlation to determine the effects of the size and BD of SLMed materials. The extracted data were sequentially used to modify the geometric and physical models of the lattice. Body-centered cubic lattice structures were fabricated by SLM, and compression tests were performed to verify the modified compression model. In addition to the BD-related grains, the cross-sectional area of the SLMed sample affects its mechanical properties. The small cross-section makes the microstructure finer because the proportion of the contour path that uses higher power is no longer negligible. The sample with small cross-section has more anisotropy because of the lack of tolerance to heterogeneity and macro defects like roughness. In this study, by analyzing samples with small cross-sections, a model consisting of an isotropic hardening law and Hill’s anisotropic yield function is established to describe the yield and plasticity behavior of the as-built SLMed Ti–6Al–4V lattice. The simulated and experimental data fit very well, verifying the methodology employed in this study.

scholarly journals APPLICATION OF DOMAIN INTEGRATED DESIGN METHODOLOGY FOR BIO-INSPIRED DESIGN- A CASE STUDY OF SUTURE PIN DESIGN

2021 ◽  
Vol 1 ◽  
pp. 487-496
Author(s):  
Pavan Tejaswi Velivela ◽  
Nikita Letov ◽  
Yuan Liu ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Cross Sections ◽  
Design Methodology ◽  
Reaction Force ◽  
Integrated Design ◽  
Total Deformation ◽  
Insertion Force ◽  
Force Reaction ◽  
The Moment ◽  
Work Done

AbstractThis paper investigates the design and development of bio-inspired suture pins that would reduce the insertion force and thereby reducing the pain in the patients. Inspired by kingfisher's beak and porcupine quills, the conceptual design of the suture pin is developed by using a unique ideation methodology that is proposed in this research. The methodology is named as Domain Integrated Design, which involves in classifying bio-inspired structures into various domains. There is little work done on such bio-inspired multifunctional aspect. In this research we have categorized the vast biological functionalities into domains namely, cellular structures, shapes, cross-sections, and surfaces. Multi-functional bio-inspired structures are designed by combining different domains. In this research, the hypothesis is verified by simulating the total deformation of tissue and the needle at the moment of puncture. The results show that the bio-inspired suture pin has a low deformation on the tissue at higher velocities at the puncture point and low deformation in its own structure when an axial force (reaction force) is applied to its tip. This makes the design stiff and thus require less force of insertion.

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