scholarly journals Evaluation of energy absorbing property of additively manufactured porous Al-10Si-0.3Mg alloys with an acorn shape at the landing of the smart lander on the inclined plane or the plane with a boulder

2020 ◽  
Vol 70 (8) ◽  
pp. 333-338
Author(s):  
Yuta Fujimori ◽  
Shiyue Guo ◽  
Koichi Kitazono
Keyword(s):  
Inclined Plane ◽  
Absorbing Property ◽  
Energy Absorbing

scholarly journals Use of Geogrids and Recycled Rubber in Railroad Infrastructure for Enhanced Performance

Geosciences ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 30 ◽  
Author(s):  
Buddhima Indraratna ◽  
Yujie Qi ◽  
Trung Ngoc Ngo ◽  
Cholachat Rujikiatkamjorn ◽  
Tim Neville ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Ground Improvement ◽  
Test Results ◽  
Track Maintenance ◽  
Work Input ◽  
The Stability ◽  
Absorbing Property ◽  
Energy Absorbing ◽  
The University ◽  
Track Deformation

Railway tracks are conventionally built on compacted ballast and structural fill layers placed above the natural (subgrade) foundation. However, during train operations, track deteriorations occur progressively due to ballast degradation. The associated track deformation is usually accompanied by a reduction in both load bearing capacity and drainage, apart from imposing frequent track maintenance. Suitable ground improvement techniques involving plastic inclusions (e.g., geogrids) and energy absorbing materials (e.g., rubber products) to enhance the stability and longevity of tracks have become increasingly popular. This paper presents the outcomes from innovative research and development measures into the use of plastic and rubber elements in rail tracks undertaken at the University of Wollongong, Australia, over the past twenty years. The results obtained from laboratory tests, mathematical modelling and numerical modelling reveal that track performance can be improved significantly by using geogrid and energy absorbing rubber products (e.g., rubber crumbs, waste tire-cell and rubber mats). Test results show that the addition of rubber materials can efficiently improve the energy absorption of the structural layer and also reduce ballast breakage. Furthermore, by incorporating the work input parameters, the energy absorbing property of the newly developed synthetic capping layer is captured by correct modelling of dilatancy. In addition, the laboratory behavior of tire cells and geogrids has been validated by numerical modelling (i.e., Finite Element Modelling-FEM, Discrete Element—DEM), and a coupled DEM-FEM modelling approach is also introduced to simulate ballast deformation.

scholarly journals The influence of rubber crumbs on the critical state behavior of waste mixtures

2019 ◽  
Vol 92 ◽  
pp. 06004
Author(s):  
Buddhima Indraratna ◽  
Yujie Qi ◽  
Ana Heitor ◽  
Jayan S. Vinod
Keyword(s):  
Critical State ◽  
Geotechnical Properties ◽  
Triaxial Tests ◽  
Test Results ◽  
State Behavior ◽  
Steel Furnace ◽  
Waste Tyres ◽  
State Behaviour ◽  
Absorbing Property ◽  
Energy Absorbing

The practical application of waste materials such as steel furnace slag (SFS) and coal wash (CW) is becoming more prevalent in many geotechnical projects. It was found that the inclusion of rubber crumbs (RCs) from recycled tyres into mixtures of SFS and CW not only solves the problem of large stockpiles of waste tyres, it also can provide an energy-absorbing medium that will reduce track degradation. In order to investigate the influence of RC on the geotechnical properties of the granular waste matrix (SFS+CW+RC), a series of monotonic consolidated drained triaxial tests were conducted on waste mixtures. The test results reveal that the inclusion of RC significantly affects the geotechnical properties of the waste mixtures, especially their critical state behaviour. Specifically, the waste matrix can achieve a critical state with a low RC content (<20%), whereas those mixtures with higher RC contents (20-40%) cannot attain a critical state within the ultimate strain capacity that can be applied to specimens using the traditional triaxial equipment. Therefore, for the waste matrix with higher RC contents extrapolation of the measured volumetric strains had to be adopted to obtain the appropriate critical state parameters. Moreover, the influence of energy absorbing property by adding RC on the critical state behaviour has also been captured through an empirical equation.

scholarly journals Inserting Stress Analysis of Combined Hexagonal Aluminum Honeycombs

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Xiangcheng Li ◽  
Kang Li ◽  
Yuliang Lin ◽  
Rong Chen ◽  
Fangyun Lu
Keyword(s):  
Structural Parameters ◽  
Base Material ◽  
Peak Stress ◽  
Displacement Curve ◽  
Out Of Plane ◽  
Aluminum Honeycomb ◽  
The One ◽  
Absorbing Property ◽  
Crushing Behavior ◽  
Energy Absorbing

Two kinds of hexagonal aluminum honeycombs are tested to study their out-of-plane crushing behavior. In the tests, honeycomb samples, including single hexagonal aluminum honeycomb (SHAH) samples and two stack-up combined hexagonal aluminum honeycombs (CHAH) samples, are compressed at a fixed quasistatic loading rate. The results show that the inserting process of CHAH can erase the initial peak stress that occurred in SHAH. Meanwhile, energy-absorbing property of combined honeycomb samples is more beneficial than the one of single honeycomb sample with the same thickness if the two types of honeycomb samples are completely crushed. Then, the applicability of the existing theoretical model for single hexagonal honeycomb is discussed, and an area equivalent method is proposed to calculate the crushing stress for nearly regular hexagonal honeycombs. Furthermore, a semiempirical formula is proposed to calculate the inserting plateau stress of two stack-up CHAH, in which structural parameters and mechanics properties of base material are concerned. The results show that the predicted stresses of three kinds of two stack-up combined honeycombs are in good agreement with the experimental data. Based on this study, stress-displacement curve of aluminum honeycombs can be designed in detail, which is very beneficial to optimize the energy-absorbing structures in engineering fields.

Cushioning and Energy Absorbing Property of Combined Aluminum Honeycomb

2015 ◽  
Vol 17 (10) ◽  
pp. 1434-1441 ◽  
Author(s):  
Yu-Liang Lin ◽  
Zhi-Feng Zhang ◽  
Rong Chen ◽  
Yan Li ◽  
Xue-Jun Wen ◽  
...  
Keyword(s):  
Aluminum Honeycomb ◽  
Absorbing Property ◽  
Energy Absorbing

Bilayer Glass Foam with Tunable Energy Absorbing Property by Localizing Voids Density

2021 ◽  
Author(s):  
Jungjin Park ◽  
John M. Howard ◽  
Avi Edery ◽  
Matthew DeMay ◽  
Norman Wereley
Keyword(s):  
Glass Foam ◽  
Absorbing Property ◽  
Energy Absorbing

scholarly journals Advancements in Geo-Inclusions for Ballasted Track: Constitutive Modelling and Numerical Analysis

2021 ◽  
Vol 13 (16) ◽  
pp. 9048
Author(s):  
Yujie Qi ◽  
Buddhima Indraratna ◽  
Trung Ngo ◽  
Fernanda Bessa Ferreira
Keyword(s):  
Cyclic Loading ◽  
Real Life ◽  
Constitutive Modelling ◽  
Discrete Element Modelling ◽  
Element Modelling ◽  
Steel Furnace ◽  
Ballasted Track ◽  
Recycled Rubber ◽  
Absorbing Property ◽  
Energy Absorbing

This paper reviewed some salient features evolving through mathematical and numerical modelling of ballasted track components incorporating recycled rubber products. Firstly, a constitutive model based on the bounding surface concept was introduced to simulate the shear stress-strain response of waste mixtures (i.e., recycled rubber crumbs, coal wash, and steel furnace slag) used for the capping layer placed below the ballast medium, whereby the energy absorbing property resulting from the inclusion of different amounts of rubber has been captured. Subsequently, key research findings concerning the inclusion of recycled rubber mats on ballasted tracks for reduced particle degradation under cyclic loading were examined and discussed. Discrete element modelling (DEM) coupled with Finite element modelling (FEM) to micro-mechanically characterise ballast behaviour with and without rubber mats offers invaluable insight into real-life track operations. In particular, this coupled DEM-FEM model facilitates the exploration of micromechanical aspects of particle breakage, contact force distributions within the granular assembly, and the orientation of contacts during cyclic loading.

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