Large size translucent wood fiber reinforced PMMA porous composites with excellent thermal, acoustic and energy absorption properties

2022 ◽  
pp. 101059
Author(s):  
JingShu Gao ◽  
Xuan Wang ◽  
JieWei Tong ◽  
BingBin Kuai ◽  
ZiHao Wang ◽  
...  
2021 ◽  
Vol 11 (12) ◽  
pp. 5445
Author(s):  
Shengyong Gan ◽  
Xingbo Fang ◽  
Xiaohui Wei

The aim of this paper is to obtain the strut friction–touchdown performance relation for designing the parameters involving the strut friction of the landing gear in a light aircraft. The numerical model of the landing gear is validated by drop test of single half-axle landing gear, which is used to obtain the energy absorption properties of strut friction in the landing process. Parametric studies are conducted using the response surface method. Based on the design of the experiment results and response surface functions, the sensitivity analysis of the design variables is implemented. Furthermore, a multi-objective optimization is carried out for good touchdown performance. The results show that the proportion of energy absorption of friction load accounts for more than 35% of the total landing impact energy. The response surface model characterizes well for the landing response, with a minimum fitting accuracy of 99.52%. The most sensitive variables for the four landing responses are the lower bearing width and the wheel moment of inertia. Moreover, the max overloading of sprung mass in LC-1 decreases by 4.84% after design optimization, which illustrates that the method of analysis and optimization on the strut friction of landing gear is efficient for improving the aircraft touchdown performance.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoqin Hao ◽  
Jia Yu ◽  
Weidong He ◽  
Yi Jiang

To solve the problem of the effective cushioning of fast-moving mechanical components in small ring-shaped spaces, the factors affecting the compression and energy absorption properties of small-sized hollow metal tubes were studied. Simulation models were constructed to analyse the influences of tube diameter, wall thickness, relative position, and number of stacked components on the compression and energy absorption properties. The correctness of the simulation method and its output were verified by experiments, which proved the effectiveness of compression and energy absorption properties of small-sized thin-walled metal tubes. The research provides support for the application of metal tube buffers in armament launch technology and engineering practice.


2003 ◽  
Author(s):  
Atsushi Yokoyama ◽  
Tamotsu Nakatani ◽  
Motoharu Tateishi ◽  
Akihiko Gotoh

2021 ◽  
Vol 33 (9) ◽  
pp. 04021252
Author(s):  
Alan Renato Estrada Cáceres ◽  
Sergio Henrique Pialarissi Cavalaro ◽  
Antonio Domingues de Figueiredo

2020 ◽  
Vol 5 (6) ◽  
pp. 702-707
Author(s):  
Fariborz M. Tehrani ◽  
Nazmieh A. Masswadi ◽  
Nathan M. Miller ◽  
Arezoo Sadrinezhad

This paper presents the results of an experimental study to investigate dynamic properties of polypropylene fiber-reinforced concrete beams with lightweight expanded shale (ES) and tire-derived aggregates (TDA). The mixture design followed past experiences in combining ES and TDA to enhance toughness and energy absorption in flexural behavior. The new mixture also contained 2% fiber by volume to improve such properties further. Experiments included compressive testing on cylindrical specimens as well as flexural testing on rectangular specimens to verify mechanical properties of fiber-reinforced tire-derived lightweight aggregate concrete (FRTDLWAC) subject to static loading. The results of these experiments confirmed reduction of mechanical strength due to addition of TDA and improvements in flexural strength due to fiber reinforcement. The dynamic testing included non-destructive impact loads applied to flexural specimens using a standard Schmidt hammer. A high-speed camera recorded the response of the system at 200 frames per second to allow detailed observations and measurements. Interpretation of energy-based dynamic results revealed that TDA enhances energy absorption through damping in flexural behavior. Results also indicated that fiber reinforcement reduces the amount of absorbed dynamic energy, even though; it enhances the absorbed strain energy due to crack bridging effect.


2011 ◽  
Vol 121-126 ◽  
pp. 75-79
Author(s):  
Bo Young Hur ◽  
Rui Zhao

The compressive behaviors of AZ31-Zr foams using Ca particles as thickening agent and CaCO3 powder as foaming agent were investigated in this study. The porosity was about 48.7%~72.9%, pore size was between 0.43~0.97 mm, and homogenous pore structures were obtained. Mechanical properties of AZ31 Mg alloy foams were investigated by means of UTM. The cellular AZ31 Mg foams possess superior comprehensive mechanical properties. The energy absorption characteristics and the effects of compression behavior on the energy absorption properties for the cellular AZ31 Mg foams have been investigated and discussed. The results show that with the addition of Zr, the Mg alloy foam has the highest energy absorption value of 16.26 MJ/m3 and the hardness value of 81.8 HV, which is much higher than that of the foams fabricated without Zr.


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