scholarly journals Soft-Landing Dynamic Analysis of a Manned Lunar Lander Em-Ploying Energy Absorption Materials of Carbon Nanotube Buckypaper

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6202
Author(s):  
Qi Yuan ◽  
Heng Chen ◽  
Hong Nie ◽  
Guang Zheng ◽  
Chen Wang ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Energy Absorption ◽  
High Energy ◽  
Absorption Efficiency ◽  
Coarse Grained ◽  
Soft Landing ◽  
Energy Absorption Efficiency ◽  
Buffer Material ◽  
High Energy Absorption ◽  
Lunar Lander

With the rapid development of the aerospace field, traditional energy absorption materials are becoming more and more inadequate and cannot meet the requirements of having a light weight, high energy absorption efficiency, and high energy absorption density. Since existing studies have shown that carbon nanotube (CNT) buckypaper is a promising candidate for energy absorption, owing to its extremely high energy absorption efficiency and remarkable mass density of energy absorption, this study explores the application of buckypaper as the landing buffer material in a manned lunar lander. Firstly, coarse-grained molecular dynamics simulations were implemented to investigate the compression stress-strain relationships of buckypapers with different densities and the effect of the compression rate within the range of the landing velocity. Then, based on a self-designed manned lunar lander, buckypapers of appropriate densities were selected to be the energy absorption materials within the landing mechanisms of the lander. For comparison, suitable aluminum honeycomb materials, the most common energy absorption materials in lunar landers, were determined for the same landing mechanisms. Afterwards, the two soft-landing multibody dynamic models are established, respectively, and their soft-landing performances under three severe landing cases are analyzed, respectively. The results depicted that the landers, respectively, adopting the two energy absorption materials well, satisfy the soft-landing performance requirements in all the cases. It is worth mentioning that the lander employing the buckypaper is proved to demonstrate a better soft-landing performance, mainly reflected in reducing the mass of the energy absorption element by 8.14 kg and lowing the maximum center-of-mass overload of the lander by 0.54 g.

Experimental Measure of Parameters: The Johnson–Cook Material Model of Extruded Mg–Gd–Y Series Alloy

2010 ◽  
Vol 77 (5) ◽  
Author(s):  
Fan Yafu ◽  
Wang Qu-dong ◽  
Ning Jun-sheng ◽  
Chen Jie ◽  
Ji Wei
Keyword(s):  
Energy Absorption ◽  
Elevated Temperatures ◽  
Material Model ◽  
Areal Density ◽  
High Energy ◽  
Thermal Softening ◽  
Absorption Efficiency ◽  
Energy Absorption Efficiency ◽  
Series Alloy ◽  
High Energy Absorption

This paper introduces a method to determine the material constants for Johnson–Cook model of an as-extruded Mg–Gd–Y series alloy by quasistatic tests on Instron 1251 and Hopkinson bar experiment at room and elevated temperatures. The results indicate that the thermal softening exponent of the current magnesium alloy is as high as 3.05, which is obviously higher than that of most metal materials, such as steel and tungsten. High thermal softening exponent usually means high energy absorption efficiency, and the comparison of the dynamic stress-strain curves between ZK60 and Mg–Gd–Y series alloy indeed indicates that the energy absorption efficiency of the Mg–Gd–Y series alloy is higher than that of ZK60. Additionally, high energy absorption efficiency makes the Mg–Gd–Y series alloy exhibit more excellent antipenetration performance than that of 7A52 aluminum alloy at equal areal density condition.

Investigation of Hydrophobic Nanoporous Particle Liquids for Impact Protection

2016 ◽  
Author(s):  
Yi Hsu ◽  
Yingtao Liu
Keyword(s):  
Energy Absorption ◽  
Impact Damage ◽  
Hydraulic Cylinder ◽  
High Energy ◽  
Absorption Efficiency ◽  
Nano Materials ◽  
Energy Absorption Efficiency ◽  
Trap Liquid ◽  
Impact Protection ◽  
High Energy Absorption

Recently, the development of hydrophobic nanoporous liquids has drawn increased attention, especially for the applications of energy absorption and impact protection. Although significant amount of research has been conducted to synthesis and characterize materials to protect structures from impact damage, the tradition methods needed to convert kinetic energy to other forms, such as heat and cell bulking, during impact protection. Due to their high energy absorption efficiency, hydrophobic nanoporous particle liquids are one of the most attractive impact mitigation materials. When impacted, such particles directly trap liquid molecules inside the non-wetting surface of nanopores in the particles. The captured impact energy is simply stored temporarily and isolated from the original energy transmission path. In this paper we investigate the energy absorption efficiency of multiple nanoporous particles and liquids. Inorganic nanoporous silica nanoparticles are investigated as the hydrophobic materials. Nanoporous particle liquids are prepared by dispersing the nano-materials in deionized water. The effects of small molecular promoters, such as methanol and ethanol, on energy absorption efficiency, are studied in this paper. The energy absorption efficiency of these liquids is experimentally characterized using an Instron mechanical testing frame and in-house develop stainless steel hydraulic cylinder system under quasi-static load conditions.

scholarly journals Design Method Using Response Surface Model for CFRP Corrugated Structure under Quasistatic Crushing

2021 ◽  
Vol 11 (21) ◽  
pp. 10178
Author(s):  
Tetsuya Gomi ◽  
Shotaro Ayuzawa ◽  
Yuta Urushiyama ◽  
Kazuhito Misaji ◽  
Susumu Takahashi ◽  
...  
Keyword(s):  
Response Surface ◽  
Energy Absorption ◽  
Design Method ◽  
Deformation Mode ◽  
High Energy ◽  
Absorption Efficiency ◽  
Response Surfaces ◽  
Surface Model ◽  
Development Period ◽  
Energy Absorption Efficiency

The development of a carbon-fiber-reinforced plastic (CFRP) part is carried out by utilizing many experimental results in deciding the design. For this reason, the development period of a CFRP structure is long and an obstacle for commercialization. In this paper, multiple regression analysis is used to derive a response surface that estimates the generated load using the shape parameters of a corrugated collision energy absorbing structure to shorten the development period. To obtain the response surface, we conducted a quasistatic crushing experiment by using the length of linear portions (pitch) and the number of stacks (thickness) of a corrugated shape as parameters. When progressive crushing mode is observed, energy absorption efficiency decreases with the increase in pitch, and increases with the increase in the number of stacks. To discuss how energy absorption efficiency changes, a comparison examination is conducted using the derived response surfaces. Results indicate that specifications with high energy absorption efficiency can be accurately selected using the response surface of primary expression. In addition, differences in deformation mode were due to the influence of the stress at the corner portion of a part.

Energy Absorption of Origami Crash Box: Numerical Simulation and Theoretical Analysis

2018 ◽  
Author(s):  
Mengyan Shi ◽  
Jiayao Ma ◽  
Yan Chen ◽  
Zhong You
Keyword(s):  
Energy Absorption ◽  
Theoretical Study ◽  
Low Cost ◽  
Deformation Mode ◽  
Absorption Efficiency ◽  
Great Promise ◽  
Good Match ◽  
Energy Absorption Efficiency ◽  
Thin Walled ◽  
Initial Peak

Thin-walled tubes as energy absorption devices are widely in use for their low cost and high manufacturability. Employing origami technique on a tube enables induction of a predetermined failure mode so as to improve its energy absorption efficiency. Here we study the energy absorption of a hexagonal tubular device named the origami crash box numerically and theoretically. Numerical simulations of the quasi-static axial crushing show that the pattern triggers a diamond-shaped mode, leading to a substantial increase in energy absorption and reduction in initial peak force. The effects of geometric parameters on the performance of the origami crash box are also investigated through a parametric study. Furthermore, a theoretical study on the deformation mode and energy absorption of the origami crash box is carried out, and a good match with numerical results is obtained. The origami crash box shows great promise in the design of energy absorption devices.

Bending Behavior of Simply-Supported Sandwich Beams Subjected to Large Deflection

2018 ◽  
Vol 777 ◽  
pp. 569-574
Author(s):  
Zhong You Xie
Keyword(s):  
Energy Absorption ◽  
Large Deflection ◽  
Absorption Efficiency ◽  
Sandwich Beams ◽  
Element Simulation ◽  
Energy Absorption Efficiency ◽  
Load Carrying ◽  
Absorption Performance ◽  
Bending Behavior ◽  
The Moment

Due to thin skins and soft core, it is apt to local indentation inducing the concurrence of geometrical and material nonlinearity in sandwich structures. In the paper, finite element simulation is used to investigate the bending behavior of lightweight sandwich beams under large deflection. A modified formulation for the moment at mid-span section of sandwich beams under large deflection is presented, and energy absorption performance is assessed based on energy absorption efficiency. In addition, it is found that no local indentation arises initially, while later that increases gradually with loading displacement increasing. The height of the mid-span section as well as load-carrying capacity decreases significantly with local indentation depth increasing.

Compressive Properties of Electroless Ni-P Coating Reinforced Magnesium Alloy Foams

2021 ◽  
Vol 889 ◽  
pp. 123-128
Author(s):  
Sheng Jun Liu ◽  
Zhi Qiang Dong ◽  
Ren Zhong Cao ◽  
Da Song ◽  
Jia An Liu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Energy Absorption ◽  
Absorption Efficiency ◽  
Absorption Capacity ◽  
Compressive Properties ◽  
Compressive Test ◽  
Energy Absorption Capacity ◽  
Energy Absorption Efficiency ◽  
Hybrid Foams ◽  
Electroless Ni

In this study, the open-cell Mg-2Zn-0.4Y foams were prepared by infiltration casting method. The Ni/Mg hybrid foams were prepared by electroless Ni-P coating on the foam struts to improve the compressive strength and energy absorption capacity. The compressive properties of the Mg alloy foams and Ni/Mg hybrid foams were studied by quasi-static compressive test. The experimental results show that the Ni-P coating is composed of crystallites. The Ni-P coating can significantly enhance the compressive strength, energy absorption capacity and energy absorption efficiency of the foams.

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