scholarly journals Investigation of nonisothermal fusion bonding for extrusion additive manufacturing of large structural parts

2021 ◽  
Author(s):  
Nevine Tagscherer ◽  
Patrick Consul ◽  
Ingo Leonard Kottenstedde ◽  
Houyem Latiri ◽  
Swen Zaremba ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Fusion Bonding ◽  
Structural Parts

Overhanging Feature Analysis for the Additive Manufacturing of Topology Optimized Structures

2018 ◽  
Author(s):  
Dylan Bender ◽  
Ahmad Barari
Keyword(s):  
Additive Manufacturing ◽  
Difference Operator ◽  
Optimized Design ◽  
3D Printer ◽  
Structural Topology ◽  
Gradient Vector ◽  
Distribution Matrix ◽  
Structural Parts ◽  
Part Orientation

This paper presents a methodology to find the optimum build orientation in the additive manufacturing of topologically optimized structural parts. The outlined methodology is based on applying a differential operator to the density distribution matrix of a topologically optimized design. The methodology is developed for 2D parts, where the profile of the geometry is constant. The 2D spatial difference operator effectively calculates the elemental density gradient vector, ultimately used to calculate the angles between i) overhanging surfaces of a topology optimized design, and ii) the build platform of a 3D printer. These angles, referred to as build angles, are used to estimate the relative amount of supporting structure required to print the design at a prescribed part orientation. This methodology can potentially be adopted to simulate the additive manufacturing surface quality of density based, structural topology optimization designs.

Topology and fibre orientation simultaneous optimisation: A design methodology for fibre-reinforced composite components

2020 ◽  
Vol 234 (9) ◽  
pp. 1267-1279 ◽  
Author(s):  
R Caivano ◽  
A Tridello ◽  
D Paolino ◽  
G Chiandussi
Keyword(s):  
Additive Manufacturing ◽  
Composite Structures ◽  
Strain Energy ◽  
Fibre Orientation ◽  
3D Models ◽  
Energy Density Distribution ◽  
Principal Stress Direction ◽  
Reinforced Composite ◽  
Structural Parts ◽  
Research Centres

Additive manufacturing for fibre-reinforced composite structures is rapidly diffusing, since it enables the production of lightweight structural parts characterized by complex geometries and tailored fibre orientations. Therefore, the development of design methodologies capable to simultaneously optimize the shape of the fibre-reinforced composite part and the fibre orientation in the additive manufacturing process is, at present, of utmost interest among industries and research centres. In this paper, a novel simultaneous optimisation method capable to optimise the topology and the local fibre orientation is proposed. The method is computationally cheap, fast convergent and permits to avoid stress peaks, working efficiently on 2D and on 3D models. The analytical formulation of the problem and the optimisation algorithm are at first described. The optimisation criteria are based on the uniform strain energy density distribution and the fibre alignement along the principal stress direction. The proposed method is then verified with several benchmarks from the literature and with a 3D illustrative example, confirming that it can be effectively and efficiently employed for the optimisation of composite components to be produced through additive manufacturing.

Feasibility Study on Fabrication of Large-Scale Offshore Structural Steel Component Using LAAM Technology

2020 ◽  
Author(s):  
Y. X. Chew ◽  
J. H. Ang ◽  
K. Y. Sastry ◽  
D. Q. Xu ◽  
S. Kuik ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Structural Steel ◽  
Large Scale ◽  
Oil And Gas ◽  
Hybrid Approach ◽  
High Strength ◽  
Weight Fraction ◽  
Steel Component ◽  
Enhance Efficiency ◽  
Structural Parts

Abstract ASTM A131 Steel, grade EH36 is a high strength steel used extensively as structural parts in shipbuilding, Oil and Gas applications. In this work, additive manufacturing of a support node connecting the main platform and columns for semi-submersible offshore vessel was performed using Laser Aided Additive Manufacturing (LAAM) process to evaluate both technical feasibility and economic viability. Both coupon and component levels LAAM process study was carried out. Properties of printed EH36 steel are significantly determined by the printing process parameters. EH36 deposited with optimized LAAM process has shown better mechanical properties than conventional rolled EH36 material. A deposition strategy was developed to distribute the accumulated residual stress, to minimize substrate distortion and stress-induced cracking in the print part. A hybrid approach combining both substrate and AM, with a 60% print to hot-rolled substrate plate weight fraction was proposed to enable printability and to enhance efficiency. Near-net-shape node was printed without cracking/delamination using optimized printing strategy. Total printing weight is 70kg and total time spent is 90 hours. It was concluded that LAAM technology is feasible for fabrication of large load bearing structural steel sections.

New additive manufacturing technology for fibre-reinforced plastics in skeleton structure

2018 ◽  
Vol 37 (20) ◽  
pp. 1246-1254 ◽  
Author(s):  
Michael Holzinger ◽  
Johannes Blase ◽  
Andreas Reinhardt ◽  
Lothar Kroll
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
High Deposition Rate ◽  
Printing Process ◽  
Reinforced Plastics ◽  
Continuous Fibre ◽  
Structural Parts ◽  
Reinforced Thermoplastics ◽  
Peel Tests ◽  
Adhesion Process

In order to process structural materials in additive manufacturing, a three-dimensional printing process with high deposition rate was developed. The process enables new design approaches for structural parts in automotive applications, combining continuous fibre-reinforced thermoplastics with short fibre-reinforced thermoplastics. For the combination of these materials, adhesion and the influence of the process parameters on adhesion is crucial. Within this study the adhesion has been measured in peel tests according to ASTM D, 6862, and the interface was investigated by optical microscopy. The adhesion process was evaluated by thermal imaging. The experiments showed that a good adhesion can be achieved during the printing process, but the continuous fibre-reinforced thermoplastic tape has to be preheated. In addition, an analytical model for the adhesion process has been introduced and validated with experimental results.

scholarly journals Synthesis and Characterisation of Acrylic Resin-Al Powder Composites Suitable for Additive Manufacturing

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1642
Author(s):  
J. J. Relinque ◽  
Ismael Romero-Ocaña ◽  
Francisco J. Navas-Martos ◽  
F. J. Delgado ◽  
M. Domínguez ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Synthesis Method ◽  
Acrylic Resin ◽  
Resin Matrix ◽  
Uv Curable ◽  
Commercial Resin ◽  
Starting Point ◽  
Powder Composites ◽  
Structural Parts ◽  
Light Scattering Effect

Stereolithography is an additive manufacturing technology commonly used to build either prototypes or final parts. Nevertheless, the manufacture of structural parts has been ruled out owing to the poor mechanical properties of conventional UV-curable resins. Moreover, the inventory of available commercial resins is still limited and they exhibit low thermal and electrical conductivity values. In this work, some composite materials were designed using Al microparticles dispersed within an SLA commercial resin matrix. These composites overcame the difficulties caused by the light scattering effect during the photopolymerisation process in the SLA technology. Dispersion of the filler was characterised by means of SEM/EDX and AFM. The composites exhibited improved thermal and mechanical behaviour in comparison with the pristine resin. The simplicity of the synthesis method used to prepare the composites provides a convenient starting point to explore new ways of designing composites for SLA with improved mechanical and functional properties.

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