scholarly journals Design and manufacture of hybrid metal composite structures using functional tooling made by additive manufacturing

2019 ◽  
Vol 5 ◽  
Author(s):  
Daniel-Alexander Türk ◽  
Fabian Rüegg ◽  
Manuel Biedermann ◽  
Mirko Meboldt

This paper presents a novel manufacturing technique for complex-shaped, hybrid metal composite structures leveraging the design freedom of additive manufacturing (AM). The key novelty of this research is an approach for an autoclave-suitable and removable tooling, which consists of a 3D-printed functional shell and a structural filler material. In this process, a layup shell is produced with AM and filled with a temperature-resistant curing support to form a removable inner tooling. The functional shell has integrated design features for the positioning and the fixation of metallic interface elements and is removed after curing through integrated breaking lines. The feasibility of this manufacturing technique is demonstrated by fabricating a novel lightweight structure for the hydraulic quadruped (HyQ) robot. Selective laser sintering (SLS) was used to produce the functional shell tooling. Titanium interface elements made via selective laser melting (SLM) were assembled to the shell and co-cured to carbon fiber using an autoclave prepreg process. The resulting multi-material structure was tested in ultimate strength and successfully operated on the HyQ robot. Weight savings of 55% compared to a reference design and the mechanical viability of the multi-material structure indicate that the proposed manufacturing technique is appropriate for individualized hybrid composite structures with complex geometries.

2021 ◽  
Vol 2021 (1) ◽  
pp. 24-44
Author(s):  
Jerzy Kozak ◽  
Tomasz Zakrzewski ◽  
Marta Witt ◽  
Martyna Dębowska-Wąsak

Abstract Additive Manufacturing (AM) based on Selective Laser Sintering (SLS) and Selective Laser Melting (SLM) is relatively widely used to manufacture complex shape parts made from metallic alloys, ceramic and polymers. Although the SLM process has many advantages over the conventional machining, main disadvantages are the relatively poor surface quality and the occurrence of the material structure defect porosity. The paper presents key problems directly related to the implementation of AM, and in particular the selection and optimization of process conditions. The first section examines the issues of dimensional accuracy, the second surface quality and porosity problem determining the mechanical properties of manufactured products.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2450
Author(s):  
Andreas Borowski ◽  
Christian Vogel ◽  
Thomas Behnisch ◽  
Vinzenz Geske ◽  
Maik Gude ◽  
...  

Continuous carbon fibre-reinforced thermoplastic composites have convincing anisotropic properties, which can be used to strengthen structural components in a local, variable and efficient way. In this study, an additive manufacturing (AM) process is introduced to fabricate in situ consolidated continuous fibre-reinforced polycarbonate. Specimens with three different nozzle temperatures were in situ consolidated and tested in a three-point bending test. Computed tomography (CT) is used for a detailed analysis of the local material structure and resulting material porosity, thus the results can be put into context with process parameters. In addition, a highly curved test structure was fabricated that demonstrates the limits of the process and dependent fibre strand folding behaviours. These experimental investigations present the potential and the challenges of additive manufacturing-based in situ consolidated continuous fibre-reinforced polycarbonate.


Author(s):  
Shiyu Zhang ◽  
Ravi Kumar Arya ◽  
William G. Whittow ◽  
Darren Cadman ◽  
Raj Mittra ◽  
...  

2021 ◽  
Vol 11 (14) ◽  
pp. 6473
Author(s):  
Valerio Acanfora ◽  
Chiara Corvino ◽  
Salvatore Saputo ◽  
Andrea Sellitto ◽  
Aniello Riccio

In this work, a preliminary numerical assessment on the application of an additive manufactured hybrid metal/composite shock absorber panels to a military seat ejection system, has been carried out. The innovative character of the shock absorber concept investigated is that the absorbing system has a thickness of only 6 mm and is composed of a pyramid-shaped lattice core that, due to its small size, can only be achieved by additive manufacturing. The mechanical behaviour of these shock absorber panels has been examined by measuring their ability to absorb and dissipate the energy generated during the ejection phase into plastic deformations, thus reducing the loads acting on pilots. In this paper the effectiveness of a system composed of five hybrid shock absorbers, with very thin thickness in order to be easily integrated between the seat and the aircraft floor, has been numerically studied by assessing their ability to absorb the energy generated during the primary ejection phase. To accomplish this, a numerical simulation of the explosion has been performed and the energy absorbed by the shock-absorbing mechanism has been assessed. The performed analysis demonstrated that the panels can absorb more than 60% of the energy generated during the explosion event while increasing the total mass of the pilot-seat system by just 0.8%.


Author(s):  
Holly K. Ault ◽  
James C. Wilkinson

Abstract A method for the integrated design and manufacture of radial plate cams is discussed. Currently, a cam-follower system is designed by specifying constraints on the motion of the follower. The physical cam contour or cam pitch curve are not mathematically defined. The cam is manufactured from the discretized follower motion program. A new method for cam design is proposed which will produce a smooth, mathematically defined cam pitch curve while maintaining the proper constraints on the follower motion. Piecewise polynomial functions in the form of rational and/or non-rational splines may be used. Cams will be manufactured using smoothed profiles and tested for improved dynamic performance. The results of initial investigations of cam profile design for this research are presented.


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