Development of a Cubic Core Lightweight Panel Using Origami-Kirigami Engineering
Zhilei Tian,
Jingchao Guan,
Wei Zhao,
Apollo B. Fukuchi,
Xilu Zhao,
Ichiro Hagiwara
Issue:
Volume 11, Issue 2, April 2023
Pages:
38-48
Received:
2 February 2023
Accepted:
21 February 2023
Published:
21 March 2023
Abstract: Honeycomb core panels are commonly used in industry as lightweight structures. However, because the bond between the face plate and the regular hexagonal core is weak, there are strength problems, such as heat and shear loads. In this study, a new cubic core panel was developed as an alternative to a honeycomb core panel. Unlike conventional honeycomb core panels, cubic cores can be processed from a single flat plate by punching and bending. Through the square contact area between the face plate and the cubic core, a double-bond integral panel structure was assembled using glue and rebates. The cubic core panel had a higher bending stiffness and bonding strength than the conventional honeycomb panel. A three-point bending test was performed on the processed cubic core panel. The relationship between the bending load and the deformation of the cubic core panel was determined. The curved part of the cubic core panel can be easily processed by cutting out a part of the material on one side of the cubic core panel in accordance with the lightweight structure of the curved part. A design formula for the curved part of the cubic core panel was derived using the curvature radius and curvature angle of the actual curved structure. A cubic core molding system was investigated using the parallel movement characteristics of the four-bar link mechanism for future mass production. An important design factor for practical use was obtained by deriving the relational expression between the bending load and plastic displacement.
Abstract: Honeycomb core panels are commonly used in industry as lightweight structures. However, because the bond between the face plate and the regular hexagonal core is weak, there are strength problems, such as heat and shear loads. In this study, a new cubic core panel was developed as an alternative to a honeycomb core panel. Unlike conventional honeyc...
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The Employability of Heavy Lift Class Ships for Logistics and Maintenance and Its Application in Military Means - Part I
Issue:
Volume 11, Issue 2, April 2023
Pages:
49-53
Received:
8 October 2022
Accepted:
7 November 2022
Published:
31 March 2023
Abstract: The purpose of this article is to present a concept of the Heavy Lift Ship already used in the maritime market, aiming to propose viable alternatives for its employability, taking as its main focus the performance of the same in military operations, however the versatility of this class of ship, allows a wide range of activities. Currently, the theme of docking, maintenance, repair and logistics is in constant evidence due to the high level demanded by operational means of navies around the world, their maintenance is of essential importance for the preparation and use of Naval Power. The implementation of a ship of this class to a fleet or fleet allows its use to perform the function of a floating dock, for example, being able to carry out the transport of other ships or floating structures. Considering the incorporation of a medium with these characteristics, it allows the performance, in addition to services related to maintenance, repair and transport, the possibility of carrying out missions together with other bodies or companies such as Petrobras, for example, in addition to supporting existing military assets and that will still be incorporated. In general, the concept of using a ship with these characteristics can be put to good use, mainly evaluating the plurality that this means can provide to a Navy.
Abstract: The purpose of this article is to present a concept of the Heavy Lift Ship already used in the maritime market, aiming to propose viable alternatives for its employability, taking as its main focus the performance of the same in military operations, however the versatility of this class of ship, allows a wide range of activities. Currently, the the...
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Reduce the Cooling FAN Blade Pass Frequency Noise in Electrical Vehicle
Issue:
Volume 11, Issue 2, April 2023
Pages:
54-59
Received:
8 March 2023
Accepted:
27 March 2023
Published:
13 April 2023
Abstract: Air duct in the inlet of the cooling fan is often used in EV (electrical vehicle) due to the usage of AGS (active grille system) and profile. It often leads to the unexpected noise of the cooling fan, the overall level and the BPF (blade pass frequency) noise becomes much worse than before significantly. The experimental results shown that the boundary conditions of the cooling fan affect the noise sensitively. So, the whole engine room CAE model is set up to apply the Computational Fluid Dynamics (CFD) and the Computational Aero Acoustics (CAA). Thus, the CFD and CAA synthesis methods are used to predict the fan noise. After theoretical analysis, it is found that the fan shroud is the most sensitive area which significantly affect the BPF noise. Then different shroud proposals are applied to find the best solutions for the BPF noise, The CAA results shown that the BPF frequency peak of the interior noise reduces 5dB (A) for the best shroud case. Then the best proposal one is manufactured and assembled in EV to validate the effects. The Noise in the EV also cut down in 5-8 dB (A). The Experimental and CAE synthesis method for the whole engine room analysis is confirmed to be useful to solve the cooling FAN BPF noise issue. According to the above researches the cooling FAN NVH design rules are drawn and used in EV NVH design.
Abstract: Air duct in the inlet of the cooling fan is often used in EV (electrical vehicle) due to the usage of AGS (active grille system) and profile. It often leads to the unexpected noise of the cooling fan, the overall level and the BPF (blade pass frequency) noise becomes much worse than before significantly. The experimental results shown that the boun...
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