Topology Optimisation Techniques

Ranjan, Rajit; Ayas, Can; Langelaar, Matthijs; Keulen, Fred van

doi:10.1201/9780429436543-2

Cited by 6 publications

(4 citation statements)

References 1 publication

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“…Moreover, this investigation demonstrated the characteristics of infill structures. The hexagonal infill had a higher yield strength compared with square and diagonal structures [ 3 , 4 , 5 ]. The tensile strength of commercial polymer materials was investigated for the Fused Filament Fabrication 3D-Printing technique.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Tensile Properties of Different Infill Pattern Structures of 3D-Printed PLA Polymers: Analysis and Validation Using Finite Element Analysis in ANSYS

Ganeshkumar¹,

Kumar

Magarajan

et al. 2022

Materials

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The advancement of 3D-printing technology has ushered in a new era in the production of machine components, building materials, prototypes, and so on. In 3D-printing techniques, the infill reduces the amount of material used, thereby reducing the printing time and sustaining the aesthetics of the products. Infill patterns play a significant role in the property of the material. In this research, the mechanical properties of specimens are investigated for gyroid, rhombile, circular, truncated octahedron, and honeycomb infill structures (hexagonal). Additionally, the tensile properties of PLA 3D-printed objects concerning their infill pattern are demonstrated. The specimens were prepared with various infill patterns to determine the tensile properties. The fracture of the specimen was simulated and the maximum yield strengths for different infill structures and infill densities were determined. The results show the hexagonal pattern of infill holds remarkable mechanical properties compared with the other infill structures. Through the variation of infill density, the desired tensile strength of PLA can be obtained based on the applications and the optimal weight of the printed parts.

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Section: Introductionmentioning

confidence: 99%

Investigation of Tensile Properties of Different Infill Pattern Structures of 3D-Printed PLA Polymers: Analysis and Validation Using Finite Element Analysis in ANSYS

Ganeshkumar¹,

Kumar

Magarajan

et al. 2022

Materials

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“…[ 1 ] Furthermore, heat accumulation in the samples along the sample height during manufacturing should also be considered. [ 1,67 ] However, the investigation of these influences was not in the focus of present work.…”

Section: Resultsmentioning

confidence: 99%

A Novel Approach to Robustly Determine Residual Stress in Additively Manufactured Microstructures Using Synchrotron Radiation

et al. 2021

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Introduction 1.1. Microstructure of Additively Manufactured MaterialsAdditive manufacturing (AM) is the subject of many recent publications. [1][2][3] Typical representatives of AM methods for the processing of metallic metals are mainly divided into three categories: wire feeding, powder feeding, and powder bed fusion systems. [3] The latter technique enables the production of metallic structures by layer-wise melting of a thin metal powder bed only using AM equipment and a sliced model generated by a computeraided design (CAD) program. The application of a powder bed in powder-based AM technology facilitates the selective processing of individual layers in complex geometry. The most commonly used powder bed fusion techniques are selective electron beam powder bed fusion (EPBF) and laser powder bed fusion (LPBF). [3,4] EPBF structures are produced in a vacuum atmosphere and at a high temperature, eventually leading to a relatively low residual stress level. In contrast, LPBF processes usually take place at temperatures up to 200 C. The localized energy input and the small melt pool sizes, respectively, in combination with low build chamber temperatures result in high temperature gradients, whereby residual stresses are favored. [5] Generally, the influence of scan vectors and related strategies is a complex topic, which crucially has to be dealt with. Scan vector lengths, orientations, the order of rotation within a specific layer, and its subsequent layers are variables in every building process. Only a very limited number of comprehensive studies have reported on the effect of the scan strategy on the density, microstructure, mechanical properties, and residual stresses of LPBF parts, as clearly stated in previous studies. [5][6][7][8] Already an increased scan path length, e.g., due to a change of cross-section of a part, can result in a severely decreased relative density as well as fundamentally changed microstructure. [9,10] The influence of parameters on the evolution of residual stresses was already numerously studied. [11,12] The authors showed that the residual stresses are mainly influenced by cooling rates, temperature gradients, and melt pool sizes. Also, a minimization of the temperature gradient by powder bed preheating is an option to reduce process-induced stresses. [1,13] The high influence of the laser power and the effect of scan strategies have been characterized.

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“…This parameter can be controlled during the slicing step of the printing process. In some previous studies, the effect of infill percentage on the mechanical properties of 3D-printed PLA structures was investigated [ 26 , 27 , 28 ]. It was observed that the infill density, extrusion temperature, infill pattern, and layer thickness had a significant role in modulating the mechanical strength and release profile of the drug [ 29 ].…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Printing of Drug-Eluting Implantable PLGA Scaffolds for Bone Regeneration

Annaji,

Mita,

Poudel

et al. 2024

Bioengineering

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Despite rapid progress in tissue engineering, the repair and regeneration of bone defects remains challenging, especially for non-homogenous and complicated defects. We have developed and characterized biodegradable drug-eluting scaffolds for bone regeneration utilizing direct powder extrusion-based three-dimensional (3D) printing techniques. The PLGA scaffolds were fabricated using poly (lactic-co-glycolic acid) (PLGA) with inherent viscosities of 0.2 dl/g and 0.4 dl/g and ketoprofen. The effect of parameters such as the infill, geometry, and wall thickness of the drug carrier on the release kinetics of ketoprofen was studied. The release studies revealed that infill density significantly impacts the release performance, where 10% infill showed faster and almost complete release of the drug, whereas 50% infill demonstrated a sustained release. The Korsmeyer–Peppas model showed the best fit for release data irrespective of the PLGA molecular weight and infill density. It was demonstrated that printing parameters such as infill density, scaffold wall thickness, and geometry played an important role in controlling the release and, therefore, in designing customized drug-eluting scaffolds for bone regeneration.

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Topology Optimisation Techniques

Cited by 6 publications

References 1 publication

Investigation of Tensile Properties of Different Infill Pattern Structures of 3D-Printed PLA Polymers: Analysis and Validation Using Finite Element Analysis in ANSYS

Investigation of Tensile Properties of Different Infill Pattern Structures of 3D-Printed PLA Polymers: Analysis and Validation Using Finite Element Analysis in ANSYS

A Novel Approach to Robustly Determine Residual Stress in Additively Manufactured Microstructures Using Synchrotron Radiation

Three-Dimensional Printing of Drug-Eluting Implantable PLGA Scaffolds for Bone Regeneration

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