Determination of a Simple Geometry for the Characterisation of the Energy Absorption Behaviour of Cast Aluminium

2014 ◽  
Vol 794-796 ◽  
pp. 628-633
Author(s):  
Matthias Hartmann ◽  
Kevin Anders
Keyword(s):  
Energy Absorption ◽  
Functional Integration ◽  
Research Work ◽  
Cross Sectional ◽  
Cast Material ◽  
Damage And Failure ◽  
Simple Geometry ◽  
Macro Scale ◽  
Energy Absorbing

Aluminium cast products are becoming more and more interesting for energy absorbing applications, as a higher functional integration can be achieved with casting processes. Therefore, it is required to find a way to characterise different aluminium alloys regarding their energy absorption behaviour. Energy absorption phenomena in materials depend on the combination of material and geometry on a macro scale level. One of the main contributions of the current research work is to show that the full realization of material absorbing capacity may not be achieved by more complex geometries. Consequently, for the characterisation of cast material under crash load, it is very important to keep the geometry influence on the energy absorption behaviour as low as possible. The ultimate aim herein is to determine an optimised geometry setup to characterise different aluminium casting materials. Three different test geometries were chosen for numerical investigations. All specimens possess the same cross-sectional area and also the same second moment of inertia. The specimens have been tested under an axial crash load at constant speed. Failure has been simulated using a Johnson-Cook damage and failure model. Their absorbing behaviours will be compared and based on the existing literature a theoretical discussion about the geometrical influence will also be given.

Crashworthiness performance of concentric structures with different cross-sectional shapes under multiple loading conditions

2020 ◽  
pp. 095440702096188
Author(s):  
Sadjad Pirmohammad
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Absorption Maximum ◽  
Element Model ◽  
Hexagonal Structure ◽  
Loading Conditions ◽  
Cross Sectional ◽  
Specific Energy Absorption ◽  
Multiple Loading ◽  
Energy Absorbing

This paper evaluates the crashworthiness performance of concentric structures with different numbers of tubes (i.e. one to five) and cross-sectional shapes (i.e. hexagon, octagon, decagon and circle) under the multiple loadings of θ = 0, 10, 20 and 30°. An experimentally validated finite element model generated in LS-DYNA is employed to calculate the crashworthiness parameters including the specific energy absorption, maximum crush force and crush force efficiency. A total of 20 concentric structures are analyzed to explore the effects of number of tubes and cross-sectional shapes on the crushing performance. A multi-criteria decision-making method known as TOPSIS is also used to compare and rank the concentric structures in terms of crushing performance. Based on the results, the hexagonal structure including two tubes and octagonal, decagonal and circular structures including three tubes demonstrate the best results among their corresponding cross-sectional shapes. These structures show 9, 39, 38 and 39% higher specific energy absorption compared to their corresponding single tubal cases, respectively. However, in comparison to single tubal cases, they generate 4, 57, 57 and 58% higher maximum crush force, respectively. As such, the values for the improvement of the crush force efficiency are 3, 26, 25 and 21%, respectively. Furthermore, the decagonal structure including three tubes provides the highest energy absorbing characteristics as compared with all the other structures studied in this research. Meanwhile, taking into account all the multiple loading conditions, this structure shows 50% higher specific energy absorption than the hexagonal structure including single tube (as the weakest structure).

Experimental study of a honeycomb energy-absorbing device for high-speed trains

2019 ◽  
Vol 234 (10) ◽  
pp. 1170-1183
Author(s):  
Benhuai Li ◽  
Zhaijun Lu ◽  
Kaibo Yan ◽  
Sisi Lu ◽  
Lingxiang Kong ◽  
...  
Keyword(s):  
Energy Absorption ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Weight Ratio ◽  
Large Mass ◽  
High Speed Train ◽  
Cross Sectional ◽  
High Speed Trains ◽  
Thin Walled ◽  
Energy Absorbing

Aluminium honeycomb is a light weight, thin-walled material with a typical multi-cellular construction and a good strength-to-weight ratio. Therefore, aluminium honeycomb can be used as an energy-absorbing device for high-speed trains. Due to its large mass and high operating speed, a high-speed train can generate large impact energy. Thus, an energy-absorbing device with a greater energy absorption capability must be designed for high-speed trains. To reduce the aerodynamic drag, the cross-sectional area of a high-speed train is limited. Therefore, a honeycomb energy-absorbing device should be designed in such a way that it is longer than the traditional energy-absorbing devices; however, this may lead to bending, destruction and uncontrollable deformation of the honeycomb; these factors are not conducive for energy absorption. In this paper, a sleeve structure was designed for high-speed trains, and a crash experiment of the energy-absorbing structure showed that the bending and destruction of the honeycomb energy-absorbing device are effectively suppressed compared with the ordinary honeycomb energy-absorbing structure. Moreover, the fluctuation of the crash force was smaller and the crash force is more stable than the traditional thin-walled energy-absorbing structure. Therefore, the deformation instability problem of the ordinary honeycomb energy-absorbing structure and the crash force fluctuation problem of the traditional thin-walled energy-absorbing structure can be solved. Then, a crash experiment and simulation involving a high-speed train with improved honeycomb energy-absorbing device was carried out, and the results showed that the deformation of the end of the train body was stable and controllable, and the train body deceleration satisfied the collision standard EN15227.

Numerical Analysis of Bearing Capacity of Suction Caisson

2008 ◽  
Author(s):  
Mahmoud Ghazavi ◽  
Kazem Barkhordari ◽  
Hooman Dabirmanesh
Keyword(s):  
Bearing Capacity ◽  
Research Work ◽  
Geometry Optimization ◽  
Uplift Capacity ◽  
Cross Sectional ◽  
Taper Angle ◽  
Suction Caisson ◽  
Parametric Studies

This paper presents a finite element modeling for determination of bearing capacity of a suction caisson subjected to vertical uplift loading. The approach looks at the uplift capacity of the caisson considering a non-uniform cross sectional area to account for a geometry optimization. For this purpose, the numerical simulation is first verified using available data from other research work especially centrifuge data. Parametric studies are then performed to investigate the role of influencing factors including taper angel. The results show that the bearing capacity of caisson increases with increasing the taper angle.

Effect of Cross Sectional Shape on the Energy Absorbing Characteristics of a Tube under Quasi-Static Loading

2013 ◽  
Vol 315 ◽  
pp. 334-338 ◽  
Author(s):  
Jaffar S. Mohamed Ali ◽  
Kassim A. Abdullah ◽  
Yulfian Aminanda
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
Cross Section ◽  
Cross Sections ◽  
Cross Sectional ◽  
Tube Cross Section ◽  
Deformation Response ◽  
Section Shape ◽  
Energy Absorbing ◽  
Sectional Shape

In this study, numerical simulation of tubes of various cross section under axial compression is carried out using LS-DYNA. The effect of varying configurations of tube cross-section shape on the deformation response, collapse mode and energy absorption characteristics of tubes under quasi-static axial compression have been studied. The validation of the finite element tube model was made by comparison with the experimental results of the square tube subjected to quasi-static axial compression. Tabulated results are presented and plots have been included for the specific energy absorption for different cross sections. The study provides an insight on ways to increasing energy absorption of light weight aluminium tubes.

Deformation and Energy Absorption Characteristics of Thin-Walled Structures

2009 ◽  
Author(s):  
Ahmed Elmarakbi ◽  
Niki Fielding
Keyword(s):  
Energy Absorption ◽  
Peak Load ◽  
Cross Sectional ◽  
Explicit Finite Element ◽  
Thin Walled Structures ◽  
Column Structure ◽  
Axial Crush ◽  
Energy Absorbing ◽  
Sectional Shape ◽  
Vehicle Crashworthiness

In this paper, to investigate the design of an energy absorbing street pole, a study of axial crush behaviour of metal thin longitudinal tubes (columns) are investigated along with a number of variables such as cross-sectional shape, shell thickness, as well as the velocity affects on columns. Tests have been carried out on the effects of bedded crumple initiators placed a various heights from the top of the column, in determining the desired value of peak load reduction, along with the effect in energy absorption of the column. With the conclusion of the desired variables for the design of an energy absorbing column, the columns are placed 90 degrees to that of the base of the model street column. Simulation of frontal impact of a vehicle and street column are analysed and compared to that of the energy absorbing street column concept. Studies are carried out by numerical simulation via the explicit finite element code LS-DYAN. Results compare the absorbed energy and the deflection of each variable, and recommend best design for the column structure which improved vehicle crashworthiness.

scholarly journals The Effect of Geometrical Non-Linearity on the Crashworthiness of Thin-Walled Conical Energy-Absorbers

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4857
Author(s):  
Michal Rogala ◽  
Jakub Gajewski ◽  
Miroslaw Ferdynus
Keyword(s):  
Energy Absorption ◽  
Wall Thickness ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Cross Sectional ◽  
Variable Wall Thickness ◽  
Thin Walled ◽  
Variable Wall ◽  
Energy Absorbers ◽  
Energy Absorbing

Crashworthiness of conical shells is known to depend on various factors. This study sets out to determine the extent to which the cross-sectional diameter contributes to their energy-absorbing properties. The object of the study was thin-walled aluminium tubes varying in upper diameter and wall thickness. The components were subjected to dynamic axial crushing kinetic energy equal to 1700 J. The numerical analysis was performed using Abaqus 6.14 software. The specific aim of the study was to determine the extent to which variable wall thickness affects the energy absorption capacity of the components under study. From the simulations, we have managed to establish a relationship between total energy absorption capacity and wall thickness. The results from the conducted analyses and the purpose-specific neural networks could provide the base for the future methodology for forecasting and optimisation of energy-absorbing systems.

Investigation of Energy Absorption Behaviour of Square Aluminium Tubes with Cutouts under Axial Compression

2019 ◽  
Vol 969 ◽  
pp. 181-186
Author(s):  
L. Prince Jeya Lal ◽  
G. Yuvaraj ◽  
S. Ramesh
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
Progressive Collapse ◽  
Research Work ◽  
Peak Load ◽  
Compressive Force ◽  
Triggering Mechanisms ◽  
Energy Absorbers ◽  
Energy Absorbing ◽  
Passenger Cabin

Energy absorbers in the form of hollow profiles are used in automobiles to mitigate energy transfer to passenger cabin during a crash event. A similar event is carried out in this research work to study the progressive compression behaviour of aluminium tubes with triggering mechanisms in the form of cut-outs. Various hollow profiles are used as energy absorbing elements. In this work, square aluminium tubes of 50x50 mm side and 150 mm length with wall thickness of 1.5 mm with cut-outs are tested under axial compression loading and the results are compared with tubes without any cutouts. Crash parameters like minimum compressive force required to fail the aluminium tube, energy absorption, peak load and progressive collapse behaviour are studied. Results reveal that tubes with slots exhibited better crash parameters than plain tubes and tubes with circular cutouts.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

Profil Penyakit Malaria Di Rumah Sakit Islam Siti Rahmah Padang Tahun 2018

2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana ◽  
Salmi Salmi
Keyword(s):  
Observational Study ◽  
Frequency Distribution ◽  
Cross Section ◽  
Laboratory Tests ◽  
Age Group ◽  
Normal Range ◽  
Cross Sectional ◽  
West Sumatra ◽  
Severity Of The Disease

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.

Profil Penyakit Malaria di Rumah Sakit Islam Siti Rahmah Padang Tahun 2018

2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana Y ◽  
Salmi Salmi
Keyword(s):  
Observational Study ◽  
Frequency Distribution ◽  
Cross Section ◽  
Laboratory Tests ◽  
Age Group ◽  
Normal Range ◽  
Cross Sectional ◽  
West Sumatra ◽  
Severity Of The Disease

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.

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